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The quality of reporting in systematic reviews: a cross sectional survey in periodontology journals

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The quality of reporting in systematic reviews: a cross sectional survey in periodontology journals

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Copyright 2020 Jassem Alsharah

The Quality of Reporting in Systematic Reviews – A Cross Sectional Survey In Periodontology
Journals

by
Jassem Alsharah, BDS

A Thesis Presented to the
FACULTY OF THE USC HERMAN OSTROW SCHOOL OF DENTISTRY
UNIVERSITY OF SOUTHERN CALIFORNIA
In Partial Fulfilment of the
Requirements for the Degree
MASTER OF SCIENCE
CRANIOFACIAL BIOLOGY

August 2020

ii
Acknowledgments
This project is a continuation of a previous project started by Dr. Husain Mohammad and
Dr. Satish Kumar. I would like to thank my mentors Dr. Kumar and Dr. Kar for their help and
support during this project in addition to my committee members Dr. Navazesh and Dr. Chen.

iii
Table of Contents
Acknowledgments………………...……………………………………………………………...ii
List of Tables……………………………………………………………………………………..iv
List of Figures…………………………………………………………………………………….v
Abstract…………………………………………………………………………………………..vii
Introduction………………………………………………………………………………………..1
Materials and Methods…………………………………………………………………………….6
Results……………………………………………………………………………………………15
Discussion………………………………………………………………………………………..22
Conclusion……………………………………………………………………………………….32
References………………………………………………………………………………………..33
Tables and Figures……………………………………………………………………………….46

iv
List of Tables
Table 1: Included Systematic Reviews…………………………………………………………..46

v
List of Figures
Figure 1: Flow Chart with Search Strategy………………………………………………………49
Figure 2: AMSTAR items JOP 2013…………………………………………………………….50
Figure 3: AMSTAR item JOP 2018……………………………………………………………..51
Figure 4: Glenny Items JOP 2013………………………………………………………………..52
Figure 5: Glenny Items JOP 2018………………………………………………………………..53
Figure 6: AMSTAR items JCP 2013…………………………………………………………….54
Figure 7: AMSTAR items JCP 2018…………………………………………………………….55
Figure 8: Glenny Items JCP 2013………………………………………………………………..56
Figure 9: Glenny Items JCP 2018………………………………………………………………..57
Figure 10: Trend in Reporting Quality JOP 2013/2018 (AMSTAR)……….…………………...58
Figure 11: Trend in Reporting Quality JOP 2013/2018 (Glenny)……………………………….59
Figure 12: Trend in Reporting Quality JCP 2013/2018 (AMSTAR)……………………………60
Figure 13: Trend in Reporting Quality JCP 2013/2018 (Glenny)……………………………….61
Figure 14: Glenny Item K – JOP 2013/2018…………………………………………………….62
Figure 15: Glenny Item K – JCP 2013/2018…………………………………………………….63
vi
Figure 16: Percentage Adherence – All systematic Reviews JOP and JCP…….……………….64

vii
Abstract
Introduction: Systematic reviews are a secondary research based on previous data that has been
published that are important in the decision-making process. The presence of bias has been
present and reported in systematic reviews in medical literature since 1980’s, and the
introduction of checklists to evaluate the quality of systematic reviews and meta-analyses has
been reported in the medical field since 1987. Validated instruments have been developed to
assess the quality of systematic reviews such as the Assessment of Multiple Systematic Reviews
(AMSTAR) and a checklist by Glenny and colleagues. The objective of this descriptive cross-
sectional survey is to assess the reporting quality of systematic reviews published in 2013 and
2018 in two commonly used periodontology journals.
Materials and Methods: Electronic and manual search using Medline of the selected journals was
done independently by two reviewers. Included systematic reviews were evaluated against the
checklist by AMSTAR and Glenny to evaluate the reporting quality of the systematic reviews
from both journals. The mean percentage of each item in the selected systematic review articles
was calculated for each systematic review included in both 2013 and 2018. Following this a
comparison of the mean percentage between the two journals was done at the different time
points previously mentioned. The descriptive trend was analyzed and the trend of the reporting
quality of systematic reviews within the Journal of Periodontology and the Journal of Clinical
Periodontology in the years 2013 and 2018 was evaluated.
Results: Regarding the AMSTAR checklist in the Journal of Periodontology, the year 2013
showed an overall adherence per systematic review ranging between 18-91% and 72-91% for the
year 2018.The Journal of Clinical Periodontology corresponding values for the overall adherence
per systematic review to the AMSTAR checklist were 45-81% in 2013 and 36-91% for the year
2018. With regards to the overall adherence per systematic review to the Glenny Checklist the
results for the Journal of Periodontology in 2013 was 38-92%, and at 2018 that value was 71-
93%. The Journal of Clinical Periodontology overall adherence to the Glenny checklist was 54-
92% for 2013 and the corresponding value for 2018 was ranging from 64-92%. When individual
items were evaluated, the AMSTAR checklist evaluation consistently showed items #4, #5 and
#11 being the least adhered to in both the Journal of Periodontology and Journal of Clinical
Periodontology at both time points. The Glenny checklist showed items [D], [E] and [J] being
the least adhered to in both journals at the evaluation of the two time points.
Conclusion: Through this project it was seen that according to the AMSTAR and Glenny
checklists, multiple items were consistently being unmet in the Journal of Periodontology and
Journal of Clinical Periodontology, and given the importance of producing high-quality
secondary research for optimal application of evidence based dentistry, evaluating and meeting
those unmet items should be emphasized to provide methodological standardization.
1
Introduction
With the increasing amount of literature and the drive to practice evidence-based
dentistry, clinicians are continuously being overwhelmed in their attempts to implement the
available evidence in clinical practice. Within the field of dentistry approximately 450 journals
are publishing at least 43,000 articles yearly
1
. As a consequence of this increasing quantity of
literature, clinicians are becoming increasingly reliant on reviews to keep up with changes in the
literature, especially systematic reviews and meta-analyses as a source of summative information
to assess the considerable amount of data for a specific clinical question. It was reported that
approximately 2,500 new systematic reviews published in English are indexed annually in the
U.S. National Library of Medicine database (PubMed)
3
. Given the significance of systematic
reviews with or without meta analyses within the field of dentistry and specifically
periodontology, it is crucial that this information is being conducted with the least amount of bias
and with great detail to aid in clinical decision-making
4
. A systematic review can be defined as
“a review of a clearly formulated question that attempts to minimize bias using systematic and
explicit methods to identify, select, critically appraise and summarize relevant research”
5
.
It is important to differentiate between systematic reviews and a narrative review. When
narrative reviews are conducted, they provide a general overview about a certain subject/topic
and they lack any inclusion criteria. Additionally, critical evaluation of the included studies is not
mandatory, and they often reflect personal opinions
6
.
Systematic reviews are a secondary research based on previous data that has been
published rather that direct experimentation. Included articles are based on specific inclusion
criteria depending on the research question
5
. Depending on the data that is included in the
systematic review, the results can be combined using statistical formulations and is referred to
2
meta-analysis. However, the feasibility of combing the data is not always possible due to
significant heterogeneity present amongst the included studies. These discrepancies can be due to
methodological, clinical or statistical reasons
1
. When the authors are unable to conduct a meta-
analysis, then results of the systematic review have to be presented as a narrative form, thus
reducing the impact of the systemic review
5
.
To start a systematic review, what has to be done first is formulating a focused question.
This is a fundamental part which is equivalent to formulating the hypothesis in any primary
research. This question should not be broad but rather narrow so that the review can act as a
conclusive summary of the literature and still be able to answer the focused question following
completion of the review
5
. Formulating the focused question is generally done using the PICO
format. In this acronym, the letter P stands for population or problem, the letter I stands for
intervention, the letter C stands for comparison and finally the letter O stands for outcomes
5
.
Following the formulation of the focused question, the inclusion criteria must be established.
These criteria will be used for selection of relevant research papers and must be balanced
between how narrow and specific the data included is. The more specific the criteria the more
homogenous the data is but that can render the systematic review less useful due to lost data.
There has to be specific consideration of the study designs that are planned to be included. For
clinical comparisons of efficacy or effectiveness, randomized control clinical trials are more
appropriate whereas when evaluating novel interventions then different study designs might be
included such as case series or animal studies
5.

The next step is to plan the search strategy. This includes the electronic search and the
search of grey literature by at least two independent reviewers. Regarding the electronic search at
least two databases should be included and there should be no language limitations. Grey
3
literature includes studies that are yet to be published or are still incomplete and are an important
part of the search as they reduce publication bias
5
.
The final results of the included studies are evaluated if they are able to be pooled
together. This can only be done when the characteristics and methodology of the included studies
are similar enough to be combined. Also, heterogeneity is statistically assessed as this is directly
related to the results and the conclusion. Finally, a conclusion is reached that does not extend
beyond answering the focused question
5
. It is also worth to note that systematic reviews can
guide future research by suggesting ways to help with pooling of data to form meta-analysis and
can also identify areas of shortcoming and thus improving the quality of data
5
.
With regards to Periodontology there has been a significant growth in the amount of
available evidence over the past 20 years. The introduction of new surgical techniques and the
availability of new biomaterials has been affecting the amount of literature that is being
published with the aim of providing evidence-based practice
2,3
. There has been several
methodological inconsistencies and presence of bias regarding systematic reviews and
conclusions that are questionable in comparison to the methodological rigor from authors that
previously published systematic reviews
3,7
. Due to these reasons, the selection criteria of
included articles and their assessment has to be strictly followed to provide more reliable results.
That when used clinically similar outcomes can be seen
3,7.

The presence of bias has been present and reported in systematic reviews in medical
literature since 1980’s, and the introduction of checklists to evaluate the quality of systematic
reviews and meta-analyses has been reported in the medical field since 1987
7
.
To counteract the methodological inconsistencies and the quality of reporting when systematic
reviews were being conducted, guidelines and checklists were developed
8
. These checklists have
4
been developed, validated, and used by clinicians, methodologists, epidemiologists in
periodontics and implant dentistry evaluations
9
. The first statement was the Quality of Reporting
of Meta-Analyses (QUOROM), it was developed in 1996 and was first published in 1999, it
included twenty-one headings and subheadings assessing the quality of different components in
conducting a of systematic reviews. These headings include but were not limited to title,
selection of studies, validity assessment, and abstract to the reporting of results
10
.
Due to questionable inter-examiner reliability and the quality of systematic reviews still
being below par, an update to the QUOROM statement was performed in 2009 and the Preferred
Reporting Items for systematic reviews and Meta-Analyses (PRISMA) was published. PRISMA
aimed to improve systematic reviews by having more transparent and complete reporting and
also to provide a continuously updated guide for systematic reviews
11
. The combination of
PRISMA and the Cochrane Handbook for systematic reviews of Interventions that was published
in 2008 have been used as guidelines for the publication of systematic reviews in the recent years
12
. However, the PRISMA checklist is not a quality assessment instrument to gauge the quality of
systematic reviews
11
, so the introduction of grading tools such as the assessment of multiple
systematic reviews (AMSTAR) checklist
13
and Glenny checklist
1
has recently become more
popular in the periodontal literature.
The AMSTAR checklist is a tool for assessing the quality of systematic reviews by
combining components that were not previously covered by other checklists published
previously
7
. In addition, other items were added due to their high impact in the results of the
systematic review according to experts in epidemiology. These items that were added include
publication status, language restrictions during the search and the evaluation of publication bias,
the overlooking of the previously mentioned items can greatly affect the influence of the results.
5
Not evaluating the status of grey literature has been associated with publication bias and over
estimation of the positive impact of the results
5
. The effect of language restriction can also have
an effect on the overall results and skew the data, and finally publication bias which was never
addressed in previous checklist can help in evaluating the amount of evidence regarding certain
research topics
7,8
. Multiple published studies with potential bias can overlook some well-
designed studies and when both are included to a systematic review the overall result is
exaggerated. These factors can affect patients negatively if the results are overstated in either a
positive or negative way and thus interventions, techniques or materials may be used.
Although the AMSTAR checklist was published to evaluate the methodological quality
of systematic reviews, it can still be used to evaluate the reporting quality. The reproducibility
and the reliability of the results achieved with AMSTAR makes it an important tool in the
biomedical field
7
. Finally, the AMSTAR checklist is also used by several worldwide agencies
including the Canadian Agency for Drugs and Technologies in Health and also it is being used
by the Cochrane Effective Practice and Organization of Care Group (EPOC)
79
.
The Glenny et al. checklist was derived from the quality of reporting of meta-analysis
criteria (QUOROM) and the Meta-analysis of Observational Studies in Epidemiology assessment
tool (MOOSE)
80
and contain fifteen different items to answer
1
. The validity of the Glenny
checklist was examined when it was first published, with high agreement rates between the
included clinicians and methodologists
1
.
The objective of this descriptive cross-sectional survey is to assess the reporting quality
of systematic reviews with or without meta-analyses in two commonly used periodontology
journals published in 2013 and 2018. The reporting quality will be assessed based on validated
tools with a main goal to help in improving the quality of reporting in future systematic reviews
6
by showing the trends and variations in the literature, so more reliable conclusions may be
achieved thus supporting our goal of evidence-based dentistry.
The journals that were selected were the Journal of Periodontology and the Journal of
Clinical Periodontology, these two journals are ranked second and third in impact factor amongst
the field of periodontology within the last five years
14
and in addition they also are flagship
publications of the two major international organizations in the field of periodontology, the
American Association of Periodontology and the European Federation of Periodontology.
The primary objective is “what is the reporting quality of systematic reviews published in the
Journal of Periodontology and Journal of Clinical Periodontology published in 2013 and 2018
according to AMSTAR
13
and Glenny
1
checklists.”
The secondary objective to be achieved is to study whether there are any differences in
the reporting quality between the two journals during 2013 and 2018, and whether there has been
improvement in the trends of reporting quality of systematic reviews in The Journal of
Periodontology and Journal of Clinical Periodontology according to AMSTAR
13
and Glenny
1

checklists.
Materials and Methods
Search Strategy:
The first step was to search for systematic reviews published between 01/01/2013 -
12/31/2013, and 01/01/2018- 12/31/2018 in the Journal of Periodontology and the Journal of
Clinical Periodontology using PubMed electronic database; this was also supplemented by a
hand search of the selected journals. The reason why PubMed was the database of choice was
because both of the selected journals are indexed in this database and thus studies fulfilling the
inclusions criteria was readily identified. Eligibility criteria of the included systematic reviews
7
were selected based on discussion and consensus between the authors of the project (J.A, S.S).
The following inclusion and exclusion criteria were used for articles selection:
Inclusion Criteria:
• Systematic reviews with and without meta-analyses published in 2013 and 2018, in Journal of
Periodontology and Journal of Clinical Periodontology.
• Systematic reviews that only includes human data.
• Systematic reviews of primary research.
Exclusion Criteria:
• Position/Consensus reports from the American Academy of Periodontology and /or the
European Federation of Periodontology.
• Reviews of secondary research.

The PubMed data base was electronically searched for articles based on the inclusion
criteria, in the search field on the PubMed website the journal title was entered (i.e. Journal of
Periodontology and Journal of Clinical Periodontology). Using the filtering tools and the
advanced search tabs, the selected volumes (2013 and 2018) and the type of article (systematic
reviews) were specified. This process was done four times, twice with Journal of Periodontology
and twice with The Journal of Clinical Periodontology for the specified years.
For Journal of Periodontology, following the initial search of the journal in PubMed,
9959 articles were found, filtering using the article type tab left us with 108 articles. Advance
search for the volume 84 (2013) revealed a total of 21 publications. Seven of the found
publications were duplicates in the Journal of Clinical Periodontology 2013 issues (i.e.
Supplemental publications of a workshop jointly held by the European Federation of
8
Periodontology and American Academy of Periodontology
15-21
). Six articles were excluded after
title and abstract screening and an additional one was excluded following methodology
screening. A total of seven systematic reviews were excluded for the following reasons; position
paper, reviews of secondary research, retrospective study, one consensus report (from
supplemental publication), narrative reviews (from supplemental publication)
22-28
. A total of 14
systematic reviews were included from volume 84
29-42
. For volume 89 (2018) the search resulted
in nine publications, five were excluded; three were position papers form the American Academy
of Periodontology and two were review papers
43-47
. A total of four systematic reviews were
included from volume 89
48-51
.
For the Journal of Clinical Periodontology, following the initial search of the journal
5598 articles were found, filtering using the article type tab left us with 218 articles. Advance
search for the volume 40 (2013) resulted in twenty four publications, seven were duplicated from
The Journal of Periodontology 2013 issue
15-21
, and three were excluded due to the following
reasons: one was an animal study, one was a review of secondary research and one was not a
scientific article
52-54
. Therefore, with the publications that were excluded, leaving a total of 14
systematic reviews that were included for evaluation
55-68
. For volume 45 (2018) the search left us
with eight articles and following the abstract and title screening and all articles were included
into the systematic review evaluation
69-76
. Although the duplicate supplemental articles fulfilling
the inclusion criteria were excluded from the final total number of systematic reviews selected
for Journal of Clinical Periodontology 2013 issues, those that were selected from Journal of
Periodontology 2013 issues were included in the data analysis of both journals, as they will have
equal effect on the results. This means that the total number of systematic reviews analyzed for
Journal of Clinical Periodontology, 2013 was 18 systematic reviews
9
Following the search electronically, a manual search was done in the selected journals at
the selected time point by the two reviewers (J.A, S.S). After all the articles were selected, they
were reviewed for eligibility to be included in the project, main reviewer assessed the articles
based on the selected checklists. Any uncertainties with the items from the checklist were
independently assessed by the second reviewer (S.S.) and in cases of disagreement persisting
then third reviewer (S.K.) was consulted.
Figure 1 demonstrates the search strategy of the project.
Following the completion of the search, the AMSTAR and Glenny et al. checklists were
used to evaluate the systematic reviews that were included from both journals by both
investigators. Each item on the checklists received a score of 1=Yes or 0=No or N/A. Following
that Inter-examiner reliability was evaluated after the scores were compared between primary
and secondary investigators (J.A, S.S) with very high degree of reliability of more than 90%
found.
Following the evaluation of all the included articles the percentage of articles in the
Journal of Periodontology and Journal of Clinical Periodontology fulfilling each of the items in
these checklist were calculated, excluding the none applicable items. Another evaluation was the
mean value of adherence of the systemic review in both journals, this was a range of the mean
adherence among the articles selected to the items in the checklists.
The mean percentage of each item in the selected systematic review articles was
calculated for each journal in both 2013 and 2018. Following this a comparison of the mean
percentage between the two journals was done at the different time points. The descriptive trend
was analyzed and the trend of the reporting quality of systematic reviews within the Journal of
10
Periodontology and the Journal of Clinical Periodontology in the years 2013 and 2018 was
evaluated.
The percentage of adherence (i.e.; using the mean adherence percentage of each
systematic review) amongst the total number of selected systematic reviews for both journals in
each year, using each checklist, was calculated at three different levels. Those percentages were
selected to provide a perspective of the percentage of SR adhering to at least half of the criteria
of each checklist, three quarters of the criteria (≥75%) or close to all the criteria (≥90%). This
was done to assess how the total number of systematic reviews adhering to each checklist relate
to the increase in percentage of adherence.
Lastly regarding Item #K from Glenny’s check list (are the results given in a narrative or
pooled statistical analysis) was not addressed in such above calculations due to the intrinsic
limitations represented by significant heterogeneity of the primary research included in some
systematic reviews, resulting in narrative presentation of the data which cannot be controlled by
the authors. A separate calculation was done looking at the percentage of pooled results for each
journal in each of the selected years. In some instances, the results from item #K was presented
in both a narrative and pooled method, so it was included in the narrative section.
Below is the copy of the AMSTAR criteria with the additional notes for each item that
was derived from the authors of the AMSTAR checklist that was published in July and
September 2010
77
:
1. Was an 'a priori' design provided?
• The research question and inclusion criteria should be established before the conduct of
the review.
11
• Note: Need to refer to a protocol, ethics approval, or pre-determined/a priori published
research objectives to score a “Yes.”
2. Was there duplicate study selection and data extraction?
• There should be at least two independent data extractors and a consensus procedure for
disagreements should be in place.
• Note: 2 people do study selection, 2 people do data extraction, consensus process or one
person checks the other’s work.
3. Was a comprehensive literature search performed?
• At least two electronic sources should be searched. The report must include years and
databases used (e.g., Central, EMBASE, and MEDLINE). Key words and/or MESH
terms must be stated and where feasible the search strategy should be provided. All
searches should be supplemented by consulting current contents, reviews, textbooks,
specialized registers, or experts in the particular field of study, and by reviewing the
references in the studies found.
• Note: If at least 2 sources + one supplementary strategy used, select “Yes” (Cochrane
register/Central counts as 2 sources; a grey literature search count as supplementary).
4. Was the status of publication (i.e. grey literature) used as an inclusion criterion?
• The authors should state that they searched for reports regardless of their publication
type. The authors should state whether or not they excluded any reports (from the
Systematic Review), based on their publication status, language etc.
• Note: If review indicates that there was a search for “grey literature” or “unpublished
literature,” indicate, “Yes.” SINGLE database, dissertations, conference proceedings, and
trial registries are all considered grey for this purpose. If searching a source that contains
both grey and non-grey, must specify that they were searching for grey/unpublished
literature.
5. Was a list of studies (included and excluded) provided?
• A list of included and excluded studies should be provided.
• Note: Acceptable if the excluded studies are referenced. If there is an electronic link to
the list but the link is dead, select “No.”
6. Were the characteristics of the included studies provided?
• In an aggregated form such as a table, data from the original studies should be provided
on the participants, interventions and outcomes. The ranges of characteristics in all the
12
studies analyzed e.g., age, race, sex, relevant socioeconomic data, disease status,
duration, severity, or other diseases should be reported.
• Note: Acceptable if not in table format as long as they are described as above.
7. Was the scientific quality of the included studies assessed and documented?
• 'A priori' methods of assessment should be provided (e.g., for effectiveness studies if the
author(s) chose to include only randomized, double-blind, placebo controlled studies, or
allocation concealment as inclusion criteria). For other types of studies, alternative items
will be relevant.
• Note: Can include use of a quality-scoring tool or checklist, e.g., Jadad scale, risk of bias,
sensitivity analysis, etc., or a description of quality items, with result for each study
(“low” or “high” is fine, as long as it is clear which studies scored “low” and which
scored “high”; a summary score/range for all studies is not acceptable).
8. Was the scientific quality of the included studies used appropriately in formulating
conclusions?
• The results of the methodological rigor and scientific quality should be considered in
the analysis and the conclusions of the review, and explicitly stated in formulating
recommendations.
• Note: Might say something such as “the results should be interpreted with caution due
to poor quality of included studies.” Cannot score “Yes” for this question if scored
“no” for question 7.
9. Were the methods used to combine the findings of studies appropriate?
• For the pooled results, a test should be done to ensure the studies were combinable, to
assess their homogeneity (i.e., Chi-squared test for homogeneity, I
2
). If heterogeneity
exists, a random effects model should be used and/or the clinical appropriateness of
combining should be taken into consideration (i.e., is it sensible to combine?).
• Note: Indicate, “Yes” if they mention or describe heterogeneity, i.e., if they explain
that they cannot pool because of heterogeneity/variability between interventions.
10. Was the likelihood of publication bias assessed?
• An assessment of publication bias should include a combination of graphical aids
(e.g., funnel plot, other available tests) and/or statistical tests (e.g., Egger
regression test, Hedges Olken).
• Note: If no test values or funnel plot included, score “No”. Score “Yes” if the
systematic review mentions that publication bias could not be assessed because there
were fewer than 10 included studies.
13
11. Was the conflict of interest included?
• Potential sources of support should be clearly acknowledged in both the
systematic review and the included studies.
• Note: To get a “Yes,” must indicate source of funding or support for the
systematic review and for each of the included studies.”
The Glenny checklist included the following questions below followed by additional notes that
the authors mutually agreed on as the authors did not provide additional explanation:
A. Did review address a focused question?
• If all the components of the focused question/questions have been addressed even if the
final conclusion is not conclusive based on the available evidence. The score is a “Yes”
B. Did authors look for appropriate papers?
• Upon discussion, consensus was reached to answer the question with a “Yes” if all the
possible keywords/Mesh terms that are related to the focused question have been used in
the search methodology.
C. Do you think authors attempted to identify all relevant studies?
• If at least two electronic databases supplemented with searching the bibliographies of the
included studies, a “Yes” can be given as an answer.
D. Search for published and unpublished literature
• If the systematic reviews reports looking at any form of unpublished literature as part of
the search strategy, the answer is a “Yes”
E. Were all languages considered?
• There should be no language restrictions to score a “Yes”
F. Was any hand searching carried out?
• If authors report manual/hand search, whether it was for references of the included
articles, or additional journals related to the question of the systematic reviews, the score
is a “Yes”
G. Was it stated that the inclusion criteria were carried out by at least two reviewers?
• “The inclusion criteria have to be applied independently by at least two reviewers when
studies are being selected for a systematic review”. In other words, the application of the
14
criteria in selecting and analyzing the articles included in the project has to be done by at
least two reviewers to score a “Yes”.
H. Did reviewers attempt to assess the quality of the included studies?
• Initially, it was thought to have the answer consistent with question 8 in AMSTAR
checklist (i.e.; was the scientific quality of the included studies assessed and
documented). The answer to this question based on AMSTAR criteria requires the
quality of each study involved in the systematic reviews to be reported. In other words,
summaries or ranges are not acceptable and will score a “No”. However, as the
systematic reviews for this project were being analyzed, we noticed that some quality
assessments were done for a group of studies that share a certain aspect in common (for
instance; Randomized Controlled Trials Vs. Controlled Clinical Trials). We believed that
in this instance, the authors did attempt to assess the quality of the included studies and
deserve credit for that, despite the fact that the assessment was not done in a manner
consistent with AMSTAR criteria. Therefore, we decided to score a “Yes” for any
attempt using quality scoring tools or checklists even if the results of the quality
assessment are given in summery or range format.
I. If so, did they include this in the analysis?
• The results of the quality should be included in the analysis and the final conclusions to
help maintaining high quality practice. If the author reports the effect the quality of the
primary studies has on the results and conclusions, a “Yes” score is given for this
question
J. Was it stated that the quality assessment was carried out by at least two reviewers?
• At least two reviewers should be involved in the quality assessment to score a “Yes”
K. Are the results given in a narrative or pooled statistical analysis?
• All the reported results have to be based on pooled data without any narrative data to be
considered as pooled.
L. If the results have been combined was it reasonable to do so?
• “Prior to conducting a Meta-analysis, consistency of the of the treatment effect across the
primary studies must be tested with a statistical heterogeneity test. In addition to that, a
clear presentation of the characteristics of the primary studies have to be included to
score a “Yes”
M. Are the results clearly displayed?
• If the results can be interpreted easily without vagueness, the score should be a “Yes”
N. Was an assessment of heterogeneity made and reasons for variation discussed?
15
• Heterogeneity, Clinical or statistical in nature must be assessed to score a “Yes”,
• Note: if authors report clinical heterogeneity without testing for it and report that the
results could not be pooled because of such heterogeneity, the score should be a “yes”
O. Were results of review interpreted appropriately?
• The results should be interpreted based on the quality of the primary research involved,
and the variations between the studies. Authors should address all the limitations, which
necessitates the results to be taken with caution to score a “Yes”
Results
Following the evaluation of the literature in the selected years in the Journal of
Periodontology and the Journal of Clinical Periodontology, a total of 40 articles were included in
this project for evaluation using the AMSTAR
13
and Glenny
1
checklists. 14 articles were
included from both the Journal of Periodontology and the Journal of Clinical Periodontology in
the year 2013.Regarding 2018, four articles were included from the Journal of periodontology
and eight articles were included from the Journal of Clinical Periodontology.
Firstly, the initial evaluation of the data involved calculating the overall adherence per
systematic review to each checklist during the selected years. Regarding the AMSTAR checklist
13
in the Journal of Periodontology, the year 2013 showed an overall adherence per systematic
review ranging between 18-91%. For the year 2018, those values for the ASMTAR checklist
were between 72-91%. When the Journal of Clinical Periodontology was evaluated, the
corresponding values for the overall adherence per systematic review to the AMSTAR
13

checklist were 45-81% in 2013 and 36-91% for the year 2018. With regards to the overall
adherence per systematic review to the Glenny Checklist
1
the results for the Journal of
Periodontology in 2013 was 38-92%, and at 2018 that value was 71-93%. When the Journal of
16
Clinical Periodontology was evaluated the overall adherence to the Glenny checklist
1
was 54-
92% for 2013 and the corresponding value for 2018 was ranging from 64-92%.
Secondly the adherence of the included systematic reviews to each item in the AMSTAR
13
and Glenny
1
checklists within the years 2013 and 2018 was evaluated for both the Journal of
Periodontology and the Journal of Clinical Periodontology. Starting with the Journal of
Periodontology and the AMSTAR checklist
13
in the year 2013 (Figure 2) showed 100%
adherence to items #1 (was a priori design provided), #6 (Were the characteristics of the
included studies provided) and #9 (Were the methods used to combine the findings of studies
appropriate). Item #3 (Was a comprehensive literature search performed) Scored 79% followed
by items #7 (Was the scientific quality of the included studies assessed and documented) and #8
(Was the scientific quality of the included studies used appropriately in formulating conclusions)
which both showed 71% adherence. Item #2 (Was there duplicate study selection and data
extraction) had 64% adherence where items #5 (Was a list of studies (included and excluded)
provided) and #10 (Was the likelihood of publication bias assessed) scored 57% and 36%
adherence. Item #4 (Was the status of publication (i.e. grey literature) used as an inclusion
criterion) showed low adherence with only 7% and item #11 (Was the conflict of interest
included) showed the lowest adherence with all the included articles with 0%.
For the results of the same journal with the AMSTAR
13
checklist again but for the 2018
time point (Figure 3), there was 100% adherence to the checklists in 7 out of the 11 items; these
were items #1,2,6,7,8,9 and #10. Item #3 showed 75% adherences while items #4 and #5 showed
50% adherence. Finally, item #11 again presented with 0% adherence.
17
Meanwhile for the Glenny
1
checklist and the Journal of Periodontology (Figure 4), in
2013 the results of the adherence to the checklist showed 100% adherence to items [A] (Did
review address a focused question), [B] (Did authors look for appropriate papers), [I] (If so did
they include this in the analysis), [M] (Are the results clearly displayed) and finally [O] (Were
results of review interpreted appropriately). Items [N] (Was an assessment of heterogeneity made
and reasons for variation discussed) and [H] (Did reviewers attempt to assess the quality of the
included studies) showed 86% adherence. Furthermore item [L] (If the results have been
combined was it reasonable to do so) showed 82% adherence while items [C] (Do you think
authors attempted to identify all relevant studies), [F] (Was any hand searching carried out) and
[G] (Was it stated that the inclusion criteria were carried out by at least two reviewers) had 79%
adherence. Lower adherence was noted in the rest of the items where item [J] (Was it stated that
the quality assessment was carried out by at least two reviewers) showed 38% and item [E]
(Were all languages considered) was 14% and finally item [D] (Search for published and
unpublished literature) showed 7% adherence only.
For the results of the Journal of Periodontology for the year 2018 with the Glenny
Checklist (Figure 5), there was 100% adherence to nine items, these are items [A], [G], [H],v[I],
[J],[L], [M],[N] and [O]. Items [B], [C] and [F] showed 75% adherence while items [D] showed
less adherence with 50% and item [E] showed the least adherence with only 25%.
Moving on to evaluating the Journal of Clinical Periodontology, regarding the AMSTAR
checklist in the year 2013 (Figure 6) 100% adherence was noted in one item only which was
item #1, while items #6 and #9 showed very high adherence also with 94%. Meanwhile an 89%
adherence was noted in item #3 with items #2 showing 83% adherence and item #8 showing
82% respectively. Some reduction in the rate of adherence was noted in the other items, with
18
item #7 with 71% adherence, item #5 presenting with 56% and item #10 showing 35%. Item #4
showed minimal adherence with only 11% and item #11 showing similar findings to the results
from the Journal of Periodontology with 0%.
For the Journal of Clinical Periodontology evaluation for the year 2018 using the
AMSTAR checklist (Figure 7), 100% adherence was seen in one item only which was item #8.
Multiple items showed 88% adherence which were items #1, #2, #4, #6, #7 and #10. A 75%
adherence was seen in two items which were items #5 and 9 and minimal adherence was seen in
two items which were item #4 with only 38% and item #11 with the exact same adherence as in
2013 with 0%.
Regarding the evaluation of the Journal of Clinical Periodontology with the Glenny
Checklist for the year 2013 (Figure 8), the evaluation of the included studies showed multiple
items with 100% in the adherence, these were the following items [A], [B], [I], [M] and [O].
Item [L] followed with 94% adherence, while items [C] and [G] had 89% adherence and these
were followed by items [H] and [N] with 88% consistency. Successively item [F] had 78% and
this was followed by item [E] with 50%. Items [D] and [J] had the lowest adherence in the
included systematic reviews with 11% and 20% respectively.
Finally in the evaluation of the Journal of Clinical Periodontology for the year 2018 using
the Glenny Checklist (Figure 9) , items [B], [C], [G], [I], [M], [N] and [O] all had 100%
adherence from the included nine studies. The items [B], [H] and [J] followed with 88%, and
item [F] showing 75%. Less adherence was noted in the remaining items with item [L] showing
50% adherence, while items [D] and [E] showing even lower adherence from the included
articles where item [D] having 35% and item [E] showing only 25% adherence.
19
The next evaluation was the mean percentage consistency of the items across the
checklists for both journals in both years. For the year 2013, the value for the mean adherence in
the Journal of Periodontology for AMSTAR was 62.3% while the Glenny value was 74.8%. For
the values from the Journal of Clinical Periodontology these were 65% and 79% respectively.
Based on the overall average percentage, the results show that the Journal of Clinical
Periodontology had a higher adherence compared to the Journal of Periodontology, where a
2.7% difference was noted in the AMSTAR checklist while a 4.2% difference was noted in the
Glenny checklist.
Regarding the values from 2018, starting with the Journal of Periodontology the
AMSTAR value for the mean percentage adherence was 79.5% while the Glenny checklist mean
was 85.7%. When the results from the Journal of Clinical periodontology was evaluated, the
results show that the AMSTAR mean percentage adherence was 74.2% while the Glenny value
was 82.3%. Based on the results, a higher average adherence was noted in the Journal of
Periodontology in comparison to the Journal of Clinical Periodontology. A 5.3% was noted in
the AMSTAR checklist while a 3.4% seen in the Glenny.
Evaluating the trend of the mean item consistency between 2013 and 2018 shows a
general improvement in the journals. For the Journal of Periodontology, the AMSTAR checklist
evaluation showed an improvement from 62.3% to79.5% while the Glenny checklist saw an
improvement from 74.8 to 85.7%. The evaluation of the trend in the Journal of Clinical
Periodontology showed a 9.2% increase in the ASMTAR checklist between 2013-2018 which
was 65% and has improved to 74.2% and the Glenny checklist showed a positive trend with an
improvement from 79% to 82.3%.
20
Upon a detailed evaluation of the trends between the year 2013 and 2018, the assessment
of the AMSTAR checklist results for the Journal of Periodontology (Figure 10) showed the same
results in items #1, #6, #9 and #11. Improvements have been seen in item #2, #7,8 and10 which
has all increased to 100%. While item #4 showed less of an increase between the years 2013 and
2018 with a 43% increase (7%-50%). The items #3 and #5 showed a reduction in the percentage
of consistency during the two time points, where item #3 showed a 4% decrease from 79% to
75% and item #5 showed a 7% decrease (57%-50%).
When the Journal of Periodontology is evaluated again according to Glenny checklist for
the trend between 2013 and 2018 for the percentage consistency (Figure 11), items [A], [I], [M]
and [O] showed 100% in the included systematic reviews. Multiple items increased to 100%
between 2013 and 2018, these were Item [G] (79-100%), [H] (86-100%), [J] (38-100%), [L] (83-
100%) and finally [N] (86-100%). Items [D] and [E] showed an increase in the percentage by
43% and 11% respectively between the two time points. Three items showed a reduction in the
consistency upon evaluation of the trend, item [B] decreased by 25% in 2018 compared to 2013,
while item [C] and [F] both showed a slight decrease of 4% in the amount of consistency, being
79% in 2013 and 75% in 2018.
Moving to the Journal of Clinical Periodontology and the trend in consistency between
2013 and 2018 according to the AMSTAR checklist (Figure 12), the only items that showed no
changes were items #1 and #11 which stayed at 100% and item #7 remained at 75%. Item #6 and
#9 both increased by 6% to reach 100% in 2018 compared to 2013. Item #5 and #10 both
showed a 1% increase compared to the previous time point increasing from 56% to 57% and
35% to 36% respectively. A Reduction was noted in the percentage consistency in items #2, #3,
21
#4 and #8, where #2 was reduced by 19% (from 83-64%), item #3 reduced by 10% (89-79%),
item #4 reduced by 4% (11-7%) and finally item #18 was reduced by 11% (82-71%).
Regarding the analysis of the trend of the Journal of Clinical Periodontology based on the
Glenny checklist (Figure 13), Items [B], [I], [M] and [O] showed 100% consistency over the two
time points while Item [H] stayed at 88%. Items [C], [G] and [N] showed similar improvements
between 2013 and 2018 increasing by 11-12% and reaching 100% consistency in 2018. Item [D]
increased slightly by 27% while item [J] consistency increased considerably by 68% (20-88%).
Significant reduction in consistency was noted in items [E] and [L] showing 25% and 44%
respectively, while minimal reduction was noted in item [A] which was reduced by 12% and
item [F] which was reduced by 3%.
Upon the evaluation of item [K] of the Glenny checklist (are the results given in a
narrative or pooled statistical analysis) it was decided prior that if the results were partially
pooled then that study would still be categorized as narrative. For the Journal of Periodontology
(Figure 14), 50% of the data was pooled in 2013, while 100% of the data was pooled in 2018.
The evaluation of the Journal of Clinical Periodontology (Figure 15) showed that 61% of the
data was pooled in 2013 while only half the data was pooled in 2018.
Finally regarding the percentage of adherence amongst the included systematic reviews
in the Journal of Periodontology and the Journal of Clinical Periodontology, it was discovered
that there was significant reduction in the number of systematic reviews adhering to the
checklists in relationship to the predetermined percentages of adherence (Figure 16) in both the
Journal of Periodontology and the Journal of Clinical Periodontology.

22
Discussion
The main objective of this cross-sectional survey was to assess the reporting quality of
systematic reviews published in Journal of Periodontology and Journal of Clinical
Periodontology. Two different checklists were used to evaluate the adherence of different
systematic reviews because it was thought that one checklist may lead to bias and supplementing
the project using a second checklist also aids in the reliability of the results. In addition no
reports were found that evaluated different periodontal journals at different time points but this
was found in other areas of medicine
90,91
. Regarding periodontology it was found that projects
looking at the quality of systematic reviews were based on specific topics such as short implants
7
, root coverage
2
and concept of platform switching
8
.
The range of adherence per included systematic reviews to each checklist in the selected
years was something that was not found in some other publications
2,7,8,9,81
, this simple calculation
gives some understanding regarding the compliance of the included systematic reviews in the
selected journals. The results showed that regarding the AMSTAR checklist
13
in the Journal of
Periodontology, the year 2013 showed an overall adherence per systematic review ranging
between 18-91% and for the year 2018, those values were between 72-91%. With regards to the
Journal of Clinical Periodontology the values for the overall adherence per systematic review to
the AMSTAR
13
checklist were 45-81% in 2013 and 36-91% for the year 2018. When the Glenny
checklist
1
was evaluated the results for the Journal of Periodontology in 2013 was between 38-
92%, and at 2018 that value was 71-93%. For the year 2013 in the Journal of Clinical
Periodontology the overall adherence to the Glenny
1
checklist was 54-92% for 2013 and the
corresponding value for 2018 was ranging from 64-92%. The results from this evaluation
23
showed that the included systematic reviews had a range of adherences that proved lack of
consistency and notable variation in the included journals during both time points
2,4,7,8,9
.
In addition, the mean consistency was also something not reported previously in past
articles. What was found was that the mean item consistency between 2013 and 2018 showed a
positive trend in the selected journals, regarding the Journal of Periodontology, the AMSTAR
checklist evaluation showed an increase in the mean percentage from 62.3% to 79.5% while the
Glenny checklist saw an improvement from 74.8 to 85.7%. When the evaluation of the trend in
the Journal of Clinical Periodontology was done, it was noted that a 9.2% increase in the
ASMTAR checklist between 2013-2018 which was 65% and an improvement to 74.2% and the
Glenny checklist showed a positive trend with an increase by 3.3% from 79% to 82.3%.
Upon evaluation some items consistently showed lack of adherence in both the Journal of
Periodontology and the Journal of Clinical Periodontology during the selected years of 2013 and
2018. In the AMSTAR checklist those were items #4,5,10 and 11. Regarding item #4 [was the
status publication (i.e. grey literature) used as an inclusion criterion] showed very low
percentages of adherence in the included systematic reviews. The same finding was detected in
other published evaluations of the reporting qualities of systematic reviews
2,7,9,81,82 ,83
. One report
that evaluated 10 systematic reviews scored 20% adherence in item #4
2
, while another
systematic review showed 12.5% adherence from the evaluation of the included 24 systematic
reviews evaluating the management of peri-implant disease
83
. These low adherence to item #4
were also seen in other publications, a 25% adherence was noted in an evaluation of systematic
reviews evaluating biological agents in the formation of bone
9
and 30% adherence was seen in
the evaluation of the effect of alveolar socket preservation
81
.
24
Furthermore, one publication showed 0% adherence to item #4 when the evaluation for
the significant of keratinized tissue on implant health was evaluated
82
. A wide range of
adherence and lack of consistency was noted in the literature in relation to item #4, can be
directly associated with publication bias which can have different implications on the results
2
.
The failure to include grey literature has been associated most commonly with skewed results
favoring positive outcomes, as there is a greater tendency for studies with positive outcome to be
published compared to studies with neutral or negative results. Careful consideration to this
aspect must be done to avoid combining multiple possibly overestimated studies and thus giving
an intervention an effect greater than what it actually presents
5
. Item #4 from AMSTAR
overlapped with Glenny item [D] as they both evaluated the search for published and
unpublished literature and presents similar results in this project and in published studies
2,7,9,81,82,83
.
The ability to access and include unpublished data into systematic reviews is not always
easily possible. Limited sources and data bases are present to access and evaluate unpublished
literature compared with published literature and in addition to possibility of limited precision
and low quality compared to evidence published in high ranked journals. But there are possible
options that include authors searching for results through other routes including trial registries,
regulatory documents, and contacting trialists of known or suspected unpublished work
84
.
Even though publication bias is assessed as a separate item in AMSTAR (item #10), it
also showed lack of adherence, ranging between 35-36% in Journal of Periodontology 2013,
Journal of Clinical Periodontology 2013 and Journal of Clinical Periodontology 2018. This is
similar to finding reported in other previously published reports in the field of periodontology,
with the results of these reports range form 0-50%
2,7,9,81,82,83
. It is worth noting that in Journal of
25
Periodontology 2018, that all four included systematic reviews adhered to item #10 and a 100%
adherence was noted, showing a possible positive trend in the Journal of Periodontology. The
results from AMSTAR item #4 and #10 can be correlated, as the lack of evaluating grey
literature can be associated with publication bias as mentioned earlier.
An additional AMSTAR item that surprisingly showed low adherence was item #5 (Was
a list of studies (included and excluded) provided), the range of adherence noted in this project
was between 50-57% in the selected time points in the Journal of Periodontology and Journal of
Clinical Periodontology. This finding was also present in other studies that evaluated the quality
of systematic reviews
2,7,9,81,82,83
. Easy access to the primary research is critical when the quality of
secondary research is considered so that the quality of the studies included can be evaluated.
Finally in AMSTAR, item #11(Was the conflict of interest included?) was consistently
failed to be met in all included systematic reviews in both the Journal of Periodontology and the
Journal of Clinical Periodontology during the years 2013 and 2018. What was reported in all
included systematic reviews was the presence of conflict of interest by the authors of the
systemic review while the primary research was not evaluated for having any conflict of interest.
It is worth noting that this finding was not consistent with other projects previously published,
where multiple publications scored item #11 similarly to this project
4,9,83
and others have scored
item #11 ranging from 40-100%
2,23,81,82
. What remains unclear is how some previously published
project have scored item #11, it is clear that the ASMTAR criteria to score a yes in this item is to
evaluate all the primary research used if any conflict of interest or sources of support were
declared and additional sources of conflict of interest are declared by the authors of the
systematic review. Interestingly, it was found that one publication mentioned that the evaluation
of the primary research included in their systematic review for conflict of interest was not done.
26
This might be a factor to why other publications have scored AMSTAR item #11 highly
especially with the way this item was evaluated in multiple other publications. It remains unclear
on how these high percentages of adherence were reached. It is obvious that conflict of interest
can have an effect on the overall results of projects, even with strict methodological criteria bias
results and statements can be made to support the project. In addition selective reporting of
negative outcomes can make a sponsored product appear more positive
85
. Amalgamation of
multiple projects with an associated risk of bias can have an overall unreliable conclusion
therefore readers have to be aware of these associations and possible reliability of the primary
sources of research included when a clinical decision will be made based on the results of the
systematic review.
Moving to the Glenny checklist, item [E] (Were all languages considered) was associated
with low adherence scores overall with scores ranging from 7-50%. Failure to include a second
language other than English was noted in multiple systematic reviews included in this project,
and similarly to the previously discussed AMSTAR items this was also seen in multiple other
studies
2,8,9,81,82
. The inclusion of other languages help increasing the overall sample size and can
increase the precision in the results and the applicability of the intervention/finding and such
action in restricting other languages is a form of bias and can have an effect on the overall results
of the systematic review. In addition, factors such as ethnicity and environment can be
overlooked when alternative languages are not considered
86
. The search for evidence in other
languages can also evaluate geographical biases in reporting findings and finally it can be an
indicator of the quality of the systematic review
87
. It is correct that the majority of well
published research is in English
3
, however a significant amount of published/unpublished
literature was not considered in the initial search even though there has been some evidence that
27
the inclusion of studies in languages other than English are unlikely to have a significant impact
on the results and the conclusion of the systematic review. However these studies can be more
relevant when publications are scarce or there are significant conflicts of interest in the published
literature
88
. The feasibility of searching and including alternative languages can be limited due to
potential difficulty in accessing non-English journals and the ability to translate their findings in
addition to the potential additional time and finances needed to satisfy this parameter
88
.
The second item that was presenting possible lack of adherence in the Glenny checklist
was item [J] (Was it stated that the quality assessment was carried out by at least two reviewers).
Even though the trend between 2013 and 2018 was positive for item [J] in both the Journal of
Periodontology (38-100%) and the Journal of Clinical Periodontology (20-88%) deficiencies was
also noted in other project with a wide range of adherence that was ranging from 20-100%
2,7,81,82,83
. The potential effect of the number of included systematic reviews in both this project in
the Journal of Periodontology 2018 being only four and with the only other found article
2
with
100% adherence being four also could be having an effect one the noted adherence to item [J]
and therefore the possible variation in the range of results presented. The process of evaluating
the quality assessment by at least two reviewers can reduce the risk of possible mistakes and any
influence on the data from a single person’s biases during the data extraction and evaluation
therefore reducing the risk of selective reporting. Potential errors in the data extraction are
unlikely to get detected by peer reviews, journal editors or the users of the systematic reviews
and therefore the inclusion of two or more extracts is crucial for the overall results and possible
impact of the systemic review
89
. Therefore, this item could be an area of focus to ensure
adequate and careful assessment of the included primary research.
28
Regarding item [K] (Are the results given in a narrative or pooled statistical analysis) in
the Glenny checklist, it is important to realize that pooling of data in a systematic review might
not be always appropriate due to significant heterogeneity due to clinical differences or statistical
differences. It is important that data from systematic reviews should be tested for heterogeneity
statistically by a random effects model or other tests, and if heterogeneity is present this has to be
explained by the authors of the systematic review. This will considerably help as this can be an
area to work on by attempting to improve the homogeneity of the data both clinically and
statistically so that future studies could combine previously published data from primary
studies
13
.
Descriptive evaluation in the trend of the adherence in the Journal of Periodontology
between 2013 and 2018 using the AMSTAR checklist revealed four items showing the same
adherence between the two time points which were items #1, #6, #9 and #11, with the first three
items being 100% at both time points while item #11 was not met in any of the included
systematic reviews. Four items which were items #2,#7,8 and #10 showed great improvement in
their trend between 2013 and 2018, where they all have shown an increase in adherence reaching
100%, item #2 increased by 36%,both items #7 and #8 showed 29% increase and item #10
showed the greatest increase in adherence from being poorly reported with 39% adherence
during 2013 to being 100% in 2018. Item #4 even though showed an increase in adherence
between 2013 and 2018 reaching 50% but it was still inconsistently being met and showed a lack
of adherence. Finally items #3 and #5 showed a decrease in adherence between 2013 and 2018,
where item #3 percentage was reduced by 4% reaching 75% in 2018 and item #5 was reduced by
7% reaching only 50%. An overall positive trend was noticed nevertheless multiple items did
29
show inconsistent results between the two time points and a lack of adherence was noted
suggesting definite room for improvement.
Moving on to the Glenny checklist and the trend that was noticed in the Journal of
Periodontology, similarly to AMSTAR four items showed 100% adherence during both time
points those being items [A], [I], [M] and [O]. Five other items showed an increase reaching
100% adherence in 2018 those were items [G] with a 21% increase, [H] with a 14% increase, [J]
62% increase, [L] 17% increase and finally [N] with 14% increase. An overall positive trend was
also noted in two other items, in item [D] a 43% increase was found reaching 50% in 2018 while
item [E] showed a 11% increase reaching 25%. Finally there was a decrease in percentage
adherence in three items being items [B] which decreased by 25% in 2018 reaching 75%, while
both items [C] and [F] showed a slight decrease of 4% reaching 75%. A positive trend was
noticed overall but similarly to the AMSTAR evaluation of the Journal of Periodontology, there
are areas where improvement can be planned. It is important to keep in mind that the number of
published systematic reviews in the year 2018 was low compared to 2013 and that could have a
possible effect on the results.
For the descriptive trend for item adherence for the Journal of Clinical Periodontology
between 2013 and 2018 and starting with the AMSTAR checklist three items scores has not
changed in both years being items #1 and #11 with the first being 100% and the second being 0%
and item #7 remaining at 75%. Two other items reached 100% in 2018 compared to 2013 being
items #6 and item #9. An increase was noted in two other items being items #5 and #10, but still
showing low adherence overall as item #5 increased from 56% to 57% and item #10 increased
from 35% to 36%. Finally a reduction in the adherence was seen in items #2, #3, #4 and #8 in
varying degrees where #2 was reduced by 19% (from 83-64%), item #3 reduced by 10% (89-
30
79%), item #4 reduced by 4% (11-7%) and finally item #18 was reduced by 11% (82-71%). An
overall similarity in the percentage adherence in individual items was noted between the two
years in the Journal of Clinical Periodontology, this suggests lack of adherence in systematic
reviews in multiple items and potential effect on the overall results of the systematic reviews in
addition to item #11 which scored 0% and was not fulfilled by any systematic review.
Finally the analysis of the trend in adherence to the individual items of the Glenny
checklist between the years 2013 and 2018 showed a total of five items remaining the same,
where the four items [B], [I], [M] and [O] showed 100% consistency over the two time points
while item [H] remained at 88% during the evaluation of the selected years. Three items did
reach 100% adherence between 2013 and 2018 reaching , those being items [C],[G] and [N],
while items [D] and [J] increased considerably with item [D] increasing by 27% reaching 38%
compared to 2013 and item [J] increasing by 68% to reach 88% in 2018. Finally, some reduction
in adherence was noticed, with item [A] reaching 88% and item [F] reaching 75% in 2018 while
items [E] and [L] showed significant reduction with 25% and 44% respectively compared to
2013. Similarly, to the AMSTAR checklist, minimal overall changes were noted between 2013
and 2018 in the Journal of Clinical Periodontology except in item [J] which increased
significantly in adherence.
It is worth noting that in the previous project Dr.Mohammad (unpublished) evaluated an
additional time point being 2010, his findings were in line with the findings of this project
regarding both checklists with a wide range of percentage adherence per included systematic
review in addition to when individual items were evaluated a similar tread was noticed with
AMSTAR items #4,#5 and #11 and Glenny items [D], [E] and [J] being the least adhered.
31
Both of the AMSTAR and Glenny checklists have been used and validated in the dental
field, and their use has enabled investigators to critically and reproducibly evaluate the quality of
published systematic reviews in the field of periodontology
7
. Some items do overlap between
the checklists but it was agreed by the authors that combining these two checklists will reduce
any biases in evaluating any included systematic reviews as well as help in correlation of these
items, in addition there are some extra items that are covered by one checklist but are not part of
the second so potentially more factors can be found that could help in improving the quality of
future research.
It is important to note that quality evaluating projects are not aimed to criticize any
published research methodologically or clinically and arbitrarily assign a number to them based
on a point system, some items may have been met but were unmentioned during the writing of
the systematic review. The main purpose of quality evaluating projects is to understand the trend
in reporting and find any areas that can be improved. This will eventually increase the
transparency of secondary research and improve the overall available data to help with decision
making process.
There are some limitations present in this project, the number of articles published in the
selected years are a limiting factor thus with more articles, more journals and more time points
the trend can be evaluated further. Regarding the checklists used, the AMSTAR checklist has
very strict criteria to fulfill each item unlike the Glenny checklist. Nevertheless, based on similar
projects in the field of periodontology, some items show lack of adherence constantly and future
projects should attempt to address those items to improve the available evidence.

32
Conclusion
Through this project it was seen that according to the AMSTAR and Glenny checklists,
multiple items were consistently being unmet in the Journal of Periodontology and Journal of
Clinical Periodontology. Specifically item #4, #5, #10 and #11 from AMSTAR and items [D],
[E], [J] from the Glenny checklist. The trend in the quality of systematic reviews according to
AMSTAR and Glenny checklist in the Journal of Periodontology showed that a positive trend
was present between 2013 and 2018, with specific items where adherence can be improved.
Regarding the Journal of Clinical Periodontology, similar finds were noted where an overall
similarity in the percentage adherence in individual items between the two years using both
checklists, except for Glenny Item [J] was a significant increase was noted. Given the importance
of producing high-quality secondary research for optimal application of evidence based dentistry
evaluating and meeting those unmet items should be emphasized to provide methodological
standardization.

33
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17. Engebretson S, Kocher T. Evidence that periodontal treatment improves diabetes
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30. D'Aiuto F, Orlandi M, Gunsolley JC. Evidence that periodontal treatment improves
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31. Engebretson S, Kocher T. Evidence that periodontal treatment improves diabetes
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32. Ide M, Papapanou PN. Epidemiology of association between maternal periodontal
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2013;84:S181-194
37
33. Lin GH, Chan HL, Wang HL. The significance of keratinized mucosa on implant health:
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38. Monje A, Chan HL, Fu JH, Suarez F, Galindo-Moreno P, Wang HL. Are short dental
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38
41. Douglas de Oliveira DW, Oliveira-Ferreira F, Flecha OD, Goncalves PF. Is surgical root
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42. Suarez F, Chan HL, Monje A, Galindo-Moreno P, Wang HL. Effect of the timing of
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46. Lin G-H, López del Amo FS, Wang H-L. Laser therapy for treatment of peri-implant
mucositis and peri-implantitis: An American Academy of Periodontology best evidence
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48. Kotsakis GA, Lian Q, Ioan- nou AL, Michalowicz BS, John M, Chu H. A network meta-
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10.1002/JPER.17-0368
49. Moraschini V, Calasans- Maia JA, Calasans-Maia MD. Association between asthma and
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2018;89:440–455. https://doi.org/10.1902/jop.2017.170363
50. Tavelli L, Barootchi S, Nguyen TV, Tattan M, Ravidà A, Wang H-L. Efficacy of tunnel
technique in the treatment of localized and multiple gingival recessions: A systematic
review and meta-analysis. Journal of Periodontology. 2018;89:1075–1090.
https://doi.org/10.1002/JPER.18-0066
51. Troiano G, Zhurakivska K, Lo Muzio L, Laino L, Cicciù M, Lo Russo L. Combination of
bone graft and resorbable membrane for alveolar ridge preservation: A systematic review,
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https://doi.org/10.1902/jop. 2017.170241
52. Faggion CM, Jr., Atieh MA, Park S. Search strategies in systematic reviews in
periodontology and implant dentistry. Journal of clinical periodontology 2013;40:883-
888.
53. Faggion CM, Jr., Giannakopoulos NN. Critical appraisal of systematic reviews on the
effect of a history of periodontitis on dental implant loss. Journal of clinical
periodontology 2013;40:542-552.
40
54. Katsamakis S, Slot DE, Van der Sluis LW, Van der Weijden F. Histological responses of
the periodontium to MTA: a systematic review. Journal of clinical periodontology
2013;40:334-344.
55. Tran DT, Gay I, Du XL, et al. Assessing periodontitis in populations: a systematic review
of the validity of partial-mouth examination protocols. Journal of clinical
periodontology 2013;40:1064-1071.
56. Li W, Xiao L, Hu J. Matrix metalloproteinase-1 promoter -1607 1G/2G polymorphism
and chronic periodontitis susceptibility: a meta-analysis and systematic review. Journal
of clinical periodontology 2013;40:1095-1103.
57. Faggion CM, Jr., Tu YK, Giannakopoulos NN. Reporting adverse events in randomized
controlled trials in periodontology: a systematic review. Journal of clinical
periodontology 2013;40:889-895.
58. Chambrone L, Preshaw PM, Rosa EF, et al. Effects of smoking cessation on the
outcomes of non-surgical periodontal therapy: a systematic review and individual patient
data meta-analysis. Journal of clinical periodontology 2013;40:607-615.
59. Sgolastra F, Petrucci A, Severino M, Graziani F, Gatto R, Monaco A. Adjunctive
photodynamic therapy to non-surgical treatment of chronic periodontitis: a systematic
review and meta-analysis. Journal of clinical periodontology 2013;40:514-526.
60. Figuero E, Carrillo-de-Albornoz A, Martin C, Tobias A, Herrera D. Effect of pregnancy
on gingival inflammation in systemically healthy women: a systematic review. Journal of
clinical periodontology 2013;40:457-473.
41
61. Schmidt JC, Sahrmann P, Weiger R, Schmidlin PR, Walter C. Biologic width
dimensions--a systematic review. Journal of clinical periodontology 2013;40:493-504.
62. Chambrone L, Foz AM, Guglielmetti MR, et al. Periodontitis and chronic kidney disease:
a systematic review of the association of diseases and the effect of periodontal treatment
on estimated glomerular filtration rate. Journal of clinical periodontology 2013;40:443-
456.
63. de Waal YC, van Winkelhoff AJ, Meijer HJ, Raghoebar GM, Winkel EG. Differences in
peri-implant conditions between fully and partially edentulous subjects: a systematic
review. Journal of clinical periodontology 2013;40:266-286.
64. Buti J, Baccini M, Nieri M, La Marca M, Pini-Prato GP. Bayesian network meta-
analysis of root coverage procedures: ranking efficacy and identification of best
treatment. Journal of clinical periodontology 2013;40:372-386.
65. Matesanz-Perez P, Garcia-Gargallo M, Figuero E, Bascones-Martinez A, Sanz M,
Herrera D. A systematic review on the effects of local antimicrobials as adjuncts to
subgingival debridement, compared with subgingival debridement alone, in the treatment
of chronic periodontitis. Journal of clinical periodontology 2013;40:227-241.
66. de Brandao ML, Vettore MV, Vidigal Junior GM. Peri-implant bone loss in cement- and
screw-retained prostheses: systematic review and meta- analysis. Journal of clinical
periodontology 2013;40:287-295.
67. Pan Y, Li D, Cai Q, et al. MMP-9 -1562C>T contributes to periodontitis susceptibility.
Journal of clinical periodontology 2013;40:125-130.
42
68. Lin PY, Cheng YW, Chu CY, Chien KL, Lin CP, Tu YK. In-office treatment for dentin
hypersensitivity: a systematic review and network meta-analysis. Journal of clinical
periodontology 2013;40:53-64.
69. Ziukaite L, Slot DE, Van der Weijden FA. Prevalence of diabetes mellitus in people
clinically diagnosed with periodontitis: A systematic review and meta-analysis of
epidemiologic studies. Journal of clinical periodontology. 2018;45:650–662.
https://doi.org/10.1111/jcpe.12839
70. Troiano G, Lo Russo L, Canullo L, Ciavarella D, Lo Muzio L, Laino L. Early and late
implant failure of submerged versus non-submerged implant healing: A systematic
review, meta-analysis and trial sequential analysis. Journal of clinical periodontology.
2018;45:613–623. https://doi.org/10.1111/ jcpe.12890
71. da Silva JC, Muniz FWMG, Oballe HJR, Andrades M, Rösing CK, Cavagni J. The effect
of periodontal therapy on oxidative stress biomarkers: A systematic review. Journal of
clinical periodontology. 2018;45:1222–1237. https://doi.org/10.1111/jcpe.12993
72. Shi T, Min M, Sun C, Zhang Y, Liang M, Sun Y. Periodontal disease and susceptibility
to breast cancer: A meta-analysis of observational studies. Journal of clinical
periodontology. 2018;45:1025–1033. https://doi.org/10.1111/jcpe.12982
73. Ramírez V, Hach M, López R. Definition of aggressive periodontitis in periodontal
research. A systematic review. Journal of clinical periodontology. 2018;45:278–284.
https://doi.org/10.1111/jcpe.12853
74. McGowan K, McGowan T, Ivanovski S. Optimal dose and duration of amoxicillin-plus-
metronidazole as an adjunct to non-surgical periodontal therapy: A systematic review and
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76. Du M, Bo T, Kapellas K, Peres AM. Prediction models for the incidence and progression
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46
Tables and Figures
Table 1 - Included systematic reviews
Article Journal Year
A systematic review of the use of growth factors in human periodontal regeneration
JoP

2013

Do implant length and width matter for short dental implants (less than 10mm)? A meta -
analysis of prospective studies
JoP 2013
The significance of keratinized mucosa on implant health: A systematic review

JoP

2013

Are short Dental implants (less than 10mm) effective? A meta-analysis on prospective
clinical trials
JoP 2013
Effect of the timing of restoration on implant marginal bone loss: A systematic review
JoP

2013

Effectiveness of periodontal treatment to improve metabolic control in patients with
chronic periodontitis and type II diabetes: a meta-analysis of Randomized Clinical Trials
JoP 2013
Is surgical root coverage effective for the treatment of cervical dentine hypersensitivity?
A systematic review
JoP

2013

Rehabilitation of deficient Alveolar ridges using Titanium Grids before and
simultaneously with implant placement: A systematic review
JoP 2013
The frequency of peri-implant disease: A systematic review and Meta-analysis JoP 2013
The clinical effect of scaling and root planing and the concomitant administration of
systemic amoxicillin and metronidazole: a systematic review
JoP

2013

A systematic review on the effects of local antimicrobials as adjunct to sub-gingival
debridement, Compared with sub- gingival debridement alone, in the treatment of chronic
periodontitis
JCP 2013
Adjunctive photodynamic therapy to non-surgical treatment of chronic periodontitis: a
systematic review and meta- analysis
JCP 2013
Assessing periodontitis in populations: a systematic review of the validity of partial mouth
examination protocol
JCP 2013
Biological width dimensions: a systematic review JCP 2013
47
Bayesian network meta-analysis of root coverage procedures: ranking efficacy and
identification of best treatment
JCP 2013
Differences in peri-implant conditions between fully and partially edentulous subjects: a
systematic review
JCP 2013
Effect of pregnancy on gingival inflammation in systemically healthy women: a
systematic review
JCP 2013
Effect of smoking cessation on the outcome of non-surgical periodontal therapy: a
systematic review and individual patient data meta-analysis
JCP 2013
In office treatment for dentin hypersensitivity: a systematic review and network meta-
analysis
JCP 2013
Matrix Metalloproteinase -1 promoter-1607 1G/2G polymorphism and chronic
periodontitis susceptibility: a meta-analysis and systematic review.
JCP 2013
MMP-9-1562C-T contributes to periodontitis susceptibility JCP 2013
Peri-implants bone loss in cement retained and screw retained prosthesis: Systematic
review
JCP 2013
Periodontitis and chronic kidney disease: a systematic review of the association of disease
and the effect of periodontal treatment on estimated glomerular filtration rate.
JCP 2013
Reporting adverse events in RCT in periodontology: a systematic review JCP 2013
Evidence that periodontal treatment improves biomarkers and CVD outcome
JCP
and
JOP
2013
Effect of periodontal disease on diabetes: Systematic review of epidemiological
observational studies
JCP
and
JOP
2013
Epidemiology of association between maternal periodontal disease and adverse pregnancy
outcomes - Systematic Review
JCP
and
JOP
2013
Evidence that periodontal treatment improves diabetes outcomes: A systematic review
and meta-analysis
JCP
and
JOP
2013
A network meta-analysis of interproximal oral hygiene methods in the reduction of
clinical indices of inflammation.
JOP 2018
Association between asthma and periodontal disease: A systematic review and meta-
analysis
JOP 2018
48
Efficacy of tunnel technique in the treatment of localized and multiple gingival
recessions: A systematic review and meta-analysis
JOP 2018
Combination of bone graft and resorbable membrane for alveolar ridge preservation: A
systematic review, meta-analysis, and trial sequential analysis
JOP 2018
Prevalence of diabetes mellitus in people clinically diagnosed with periodontitis: A
systematic review and meta-analysis of epidemiologic studies
JCP 2018
Early and late implant failure of submerged versus non-submerged implant healing: A
systematic review, meta-analysis and trial sequential analysis
JCP 2018
The effect of periodontal therapy on oxidative stress biomarkers: A systematic review
JCP 2018
Periodontal disease and susceptibility to breast cancer: A meta-analysis of observational
studies
JCP 2018
Definition of aggressive periodontitis in periodontal research. A systematic review
JCP 2018
Optimal dose and duration of amoxicillin-plus-metronidazole as an adjunct to non-
surgical periodontal therapy: A systematic review and meta-analysis of randomized,
placebo-controlled trials
JCP 2018
A systematic review and meta-analysis of epidemiologic observational evidence on the
effect of periodontitis on diabetes
JCP 2018
Prediction models for the incidence and progression of periodontitis: A systematic review
JCP 2018

49
Figure 1 - Flow chart with search strategy

50
Figure 2 - AMSTAR items Journal of Periodontology 2013

51
Figure 3 - AMSTAR items Journal of Periodontology 2018

52
Figure 4 - Glenny items Journal of Periodontology 2013

53
Figure 5 - Glenny items Journal of Periodontology 2018

54
Figure 6 - AMSTAR items Journal of Clinical Periodontology 2013

55
Figure 7 - AMSTAR items Journal of Clinical Periodontology 2018

56
Figure 8 - Glenny items Journal of Clinical Periodontology 2013

57
Figure 9 - Glenny items Journal of Clinical Periodontology 2018

58
Figure 10 - Trends in Reporting Quality in Journal of Periodontology 2013/2018 (AMSTAR)

59
Figure 11 - Trends in Reporting Quality in Journal of Periodontology 2013/2018 (Glenny)

-%
20%
40%
60%
80%
100%
1 2 3 4 5 6 7 8 9 10 11
100% 100%
75%
50% 50%
100% 100% 100% 100% 100%
-%
AMSTAR Items "JOP 2018"
% Consistency
-%
20%
40%
60%
80%
100%
A B C D E F G H I J L M N O
100%
75% 75%
50%
25%
75%
100% 100% 100% 100% 100% 100% 100% 100%
Glenny Items "JOP 2018"
% Consistency
50% 50%
Item K "JOP 2013"
Pooled Narrative/Both
61%
39%
Item K "JCP 2013"
Pooled Narrative/Both
-%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
1 2 3 4 5 6 7 8 9 10 11
% Consistency 2018 100% 100% 75% 50% 50% 100% 100% 100% 100% 100% -%
% Consistency 2013 100% 64% 79% 7% 57% 100% 71% 71% 100% 36% -%
Trends of Reporting Quality in JOP 2013-2018 (AMSTAR)
-%
20%
40%
60%
80%
100%
1 2 3 4 5 6 7 8 9 10 11
88% 88% 88%
38%
75%
88% 88%
100%
75%
88%
-%
AMSTAR Items "JCP 2018"
% Consistency
-%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
1 2 3 4 5 6 7 8 9 10 11
% Consistency 2018 100% 64% 79% 7% 57% 100% 71% 71% 100% 36% -%
% Consistency 2013 100% 83% 89% 11% 56% 94% 71% 82% 94% 35% -%
Trends of Reporting Quality in JCP 2013-2018 (AMSTAR)
50% 50%
Item K "JCP 2018"
Pooled Narrative/Both
100%
Item K "JOP 2018"
Pooled Narrative/Both
-%
20%
40%
60%
80%
100%
A B C D E F G H I J L M N O
88%
100% 100%
38%
25%
75%
100%
88%
100%
88%
50%
100% 100% 100%
Glenny Items "JCP 2018"
% Consistency
-%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
A B C D E F G H I J L M N O
% Consistency 2018 100% 75% 75% 50% 25% 75% 100% 100% 100% 100% 100% 100% 100% 100%
% Consistency 2013 100% 100% 79% 7% 14% 79% 79% 86% 100% 38% 82% 100% 86% 100%
Trends of Reporting Quality in JOP 2013-2018 (Glenny)
-%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
A B C D E F G H I J L M N O
% Consistency 2018 88% 100% 100% 38% 25% 75% 100% 88% 100% 88% 50% 100% 100% 100%
% Consistency 2013 100% 100% 89% 11% 50% 78% 89% 88% 100% 20% 94% 100% 88% 100%
Trends of Reporting Quality in JCP 2013-2018 (Glenny)
-%
20%
40%
60%
80%
100%
≥50% ≥75% ≥90%
AMSTAR 91% 73% 64%
Glenny 93% 86% 64%
% Of Adherence Amongst All SR in JOP
-%
10%
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30%
40%
50%
60%
70%
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90%
≥50% ≥75% ≥90%
AMSTAR 82% 82% 9%
Glenny 86% 79% 50%
% Of Adherence Amongst All SR in JOP
60
Figure 12 - Trends in Reporting Quality in Journal of Clinical Periodontology 2013/2018
(AMSTAR)

61
Figure 13 - Trends in Reporting Quality in Journal of Clinical Periodontology 2013/2018
(Glenny)

-%
20%
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100%
1 2 3 4 5 6 7 8 9 10 11
100% 100%
75%
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100% 100% 100% 100% 100%
-%
AMSTAR Items "JOP 2018"
% Consistency
-%
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A B C D E F G H I J L M N O
100%
75% 75%
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75%
100% 100% 100% 100% 100% 100% 100% 100%
Glenny Items "JOP 2018"
% Consistency
50% 50%
Item K "JOP 2013"
Pooled Narrative/Both
61%
39%
Item K "JCP 2013"
Pooled Narrative/Both
-%
10%
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100%
1 2 3 4 5 6 7 8 9 10 11
% Consistency 2018 100% 100% 75% 50% 50% 100% 100% 100% 100% 100% -%
% Consistency 2013 100% 64% 79% 7% 57% 100% 71% 71% 100% 36% -%
Trends of Reporting Quality in JOP 2013-2018 (AMSTAR)
-%
20%
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100%
1 2 3 4 5 6 7 8 9 10 11
88% 88% 88%
38%
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-%
AMSTAR Items "JCP 2018"
% Consistency
-%
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1 2 3 4 5 6 7 8 9 10 11
% Consistency 2018 100% 64% 79% 7% 57% 100% 71% 71% 100% 36% -%
% Consistency 2013 100% 83% 89% 11% 56% 94% 71% 82% 94% 35% -%
Trends of Reporting Quality in JCP 2013-2018 (AMSTAR)
50% 50%
Item K "JCP 2018"
Pooled Narrative/Both
100%
Item K "JOP 2018"
Pooled Narrative/Both
-%
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A B C D E F G H I J L M N O
88%
100% 100%
38%
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Glenny Items "JCP 2018"
% Consistency
-%
10%
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100%
A B C D E F G H I J L M N O
% Consistency 2018 100% 75% 75% 50% 25% 75% 100% 100% 100% 100% 100% 100% 100% 100%
% Consistency 2013 100% 100% 79% 7% 14% 79% 79% 86% 100% 38% 82% 100% 86% 100%
Trends of Reporting Quality in JOP 2013-2018 (Glenny)
-%
10%
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A B C D E F G H I J L M N O
% Consistency 2018 88% 100% 100% 38% 25% 75% 100% 88% 100% 88% 50% 100% 100% 100%
% Consistency 2013 100% 100% 89% 11% 50% 78% 89% 88% 100% 20% 94% 100% 88% 100%
Trends of Reporting Quality in JCP 2013-2018 (Glenny)
-%
20%
40%
60%
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100%
≥50% ≥75% ≥90%
AMSTAR 91% 73% 64%
Glenny 93% 86% 64%
% Of Adherence Amongst All SR in JOP
-%
10%
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50%
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≥50% ≥75% ≥90%
AMSTAR 82% 82% 9%
Glenny 86% 79% 50%
% Of Adherence Amongst All SR in JOP
62
Figure 14 - Glenny Item K – Journal of Periodontology 2013/2018

-%
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AMSTAR Items "JOP 2018"
% Consistency
-%
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A B C D E F G H I J L M N O
100%
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Glenny Items "JOP 2018"
% Consistency
50% 50%
Item K "JOP 2013"
Pooled Narrative/Both
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Item K "JCP 2013"
Pooled Narrative/Both
-%
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1 2 3 4 5 6 7 8 9 10 11
% Consistency 2018 100% 100% 75% 50% 50% 100% 100% 100% 100% 100% -%
% Consistency 2013 100% 64% 79% 7% 57% 100% 71% 71% 100% 36% -%
Trends of Reporting Quality in JOP 2013-2018 (AMSTAR)
-%
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1 2 3 4 5 6 7 8 9 10 11
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AMSTAR Items "JCP 2018"
% Consistency
-%
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1 2 3 4 5 6 7 8 9 10 11
% Consistency 2018 100% 64% 79% 7% 57% 100% 71% 71% 100% 36% -%
% Consistency 2013 100% 83% 89% 11% 56% 94% 71% 82% 94% 35% -%
Trends of Reporting Quality in JCP 2013-2018 (AMSTAR)
50% 50%
Item K "JCP 2018"
Pooled Narrative/Both
100%
Item K "JOP 2018"
Pooled Narrative/Both
-%
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A B C D E F G H I J L M N O
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Glenny Items "JCP 2018"
% Consistency
-%
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A B C D E F G H I J L M N O
% Consistency 2018 100% 75% 75% 50% 25% 75% 100% 100% 100% 100% 100% 100% 100% 100%
% Consistency 2013 100% 100% 79% 7% 14% 79% 79% 86% 100% 38% 82% 100% 86% 100%
Trends of Reporting Quality in JOP 2013-2018 (Glenny)
-%
10%
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A B C D E F G H I J L M N O
% Consistency 2018 88% 100% 100% 38% 25% 75% 100% 88% 100% 88% 50% 100% 100% 100%
% Consistency 2013 100% 100% 89% 11% 50% 78% 89% 88% 100% 20% 94% 100% 88% 100%
Trends of Reporting Quality in JCP 2013-2018 (Glenny)
-%
20%
40%
60%
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100%
≥50% ≥75% ≥90%
AMSTAR 91% 73% 64%
Glenny 93% 86% 64%
% Of Adherence Amongst All SR in JOP
-%
10%
20%
30%
40%
50%
60%
70%
80%
90%
≥50% ≥75% ≥90%
AMSTAR 82% 82% 9%
Glenny 86% 79% 50%
% Of Adherence Amongst All SR in JOP
63
Figure 15 - Glenny Item K – Journal of Clinical Periodontology 2013/2018

-%
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-%
AMSTAR Items "JOP 2018"
% Consistency
-%
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100%
A B C D E F G H I J L M N O
100%
75% 75%
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100% 100% 100% 100% 100% 100% 100% 100%
Glenny Items "JOP 2018"
% Consistency
50% 50%
Item K "JOP 2013"
Pooled Narrative/Both
61%
39%
Item K "JCP 2013"
Pooled Narrative/Both
-%
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1 2 3 4 5 6 7 8 9 10 11
% Consistency 2018 100% 100% 75% 50% 50% 100% 100% 100% 100% 100% -%
% Consistency 2013 100% 64% 79% 7% 57% 100% 71% 71% 100% 36% -%
Trends of Reporting Quality in JOP 2013-2018 (AMSTAR)
-%
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1 2 3 4 5 6 7 8 9 10 11
88% 88% 88%
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AMSTAR Items "JCP 2018"
% Consistency
-%
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1 2 3 4 5 6 7 8 9 10 11
% Consistency 2018 100% 64% 79% 7% 57% 100% 71% 71% 100% 36% -%
% Consistency 2013 100% 83% 89% 11% 56% 94% 71% 82% 94% 35% -%
Trends of Reporting Quality in JCP 2013-2018 (AMSTAR)
50% 50%
Item K "JCP 2018"
Pooled Narrative/Both
100%
Item K "JOP 2018"
Pooled Narrative/Both
-%
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A B C D E F G H I J L M N O
88%
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Glenny Items "JCP 2018"
% Consistency
-%
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100%
A B C D E F G H I J L M N O
% Consistency 2018 100% 75% 75% 50% 25% 75% 100% 100% 100% 100% 100% 100% 100% 100%
% Consistency 2013 100% 100% 79% 7% 14% 79% 79% 86% 100% 38% 82% 100% 86% 100%
Trends of Reporting Quality in JOP 2013-2018 (Glenny)
-%
10%
20%
30%
40%
50%
60%
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80%
90%
100%
A B C D E F G H I J L M N O
% Consistency 2018 88% 100% 100% 38% 25% 75% 100% 88% 100% 88% 50% 100% 100% 100%
% Consistency 2013 100% 100% 89% 11% 50% 78% 89% 88% 100% 20% 94% 100% 88% 100%
Trends of Reporting Quality in JCP 2013-2018 (Glenny)
-%
20%
40%
60%
80%
100%
≥50% ≥75% ≥90%
AMSTAR 91% 73% 64%
Glenny 93% 86% 64%
% Of Adherence Amongst All SR in JOP
-%
10%
20%
30%
40%
50%
60%
70%
80%
90%
≥50% ≥75% ≥90%
AMSTAR 82% 82% 9%
Glenny 86% 79% 50%
% Of Adherence Amongst All SR in JOP
64
Figure 16 - Percentage Adherence – All systematic Reviews Journal of Periodontology and
Journal of Clinical Periodontology

Abstract (if available)

Abstract Introduction: Systematic reviews are a secondary research based on previous data that has been published that are important in the decision-making process. The presence of bias has been present and reported in systematic reviews in medical literature since 1980’s, and the introduction of checklists to evaluate the quality of systematic reviews and meta-analyses has been reported in the medical field since 1987. Validated instruments have been developed to assess the quality of systematic reviews such as the Assessment of Multiple Systematic Reviews (AMSTAR) and a checklist by Glenny and colleagues. The objective of this descriptive cross-sectional survey is to assess the reporting quality of systematic reviews published in 2013 and 2018 in two commonly used periodontology journals. ❧ Materials and Methods: Electronic and manual search using Medline of the selected journals was done independently by two reviewers. Included systematic reviews were evaluated against the checklist by AMSTAR and Glenny to evaluate the reporting quality of the systematic reviews from both journals. The mean percentage of each item in the selected systematic review articles was calculated for each systematic review included in both 2013 and 2018. Following this a comparison of the mean percentage between the two journals was done at the different time points previously mentioned. The descriptive trend was analyzed and the trend of the reporting quality of systematic reviews within the Journal of Periodontology and the Journal of Clinical Periodontology in the years 2013 and 2018 was evaluated. ❧ Results: Regarding the AMSTAR checklist in the Journal of Periodontology, the year 2013 showed an overall adherence per systematic review ranging between 18-91% and 72-91% for the year 2018. The Journal of Clinical Periodontology corresponding values for the overall adherence per systematic review to the AMSTAR checklist were 45-81% in 2013 and 36-91% for the year 2018. With regards to the overall adherence per systematic review to the Glenny Checklist the results for the Journal of Periodontology in 2013 was 38-92%, and at 2018 that value was 71-93%. The Journal of Clinical Periodontology overall adherence to the Glenny checklist was 54-92% for 2013 and the corresponding value for 2018 was ranging from 64-92%. When individual items were evaluated, the AMSTAR checklist evaluation consistently showed items #4, #5 and #11 being the least adhered to in both the Journal of Periodontology and Journal of Clinical Periodontology at both time points. The Glenny checklist showed items [D], [E] and [J] being the least adhered to in both journals at the evaluation of the two time points. ❧ Conclusion: Through this project it was seen that according to the AMSTAR and Glenny checklists, multiple items were consistently being unmet in the Journal of Periodontology and Journal of Clinical Periodontology, and given the importance of producing high-quality secondary research for optimal application of evidence based dentistry, evaluating and meeting those unmet items should be emphasized to provide methodological standardization.

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Asset Metadata

Creator Alsharah, Jassem (author)

Core Title The quality of reporting in systematic reviews: a cross sectional survey in periodontology journals

School School of Dentistry

Degree Master of Science

Degree Program Craniofacial Biology

Publication Date 07/29/2020

Defense Date 05/20/2020

Publisher University of Southern California (original), University of Southern California. Libraries (digital)

Tag AMSTAR,Glenny,OAI-PMH Harvest,periodontology,quality of reporting

Language English

Contributor Electronically uploaded by the author (provenance)

Advisor Kar, Kian (committee chair), Chen, Casey (committee member), Kumar, Satish (committee member), Navazesh, Mahvash (committee member)

Creator Email alsharah@usc.edu,j_alsharah@hotmail.com

Permanent Link (DOI) https://doi.org/10.25549/usctheses-c89-350713

Unique identifier UC11665938

Identifier etd-AlsharahJa-8815.pdf (filename),usctheses-c89-350713 (legacy record id)

Legacy Identifier etd-AlsharahJa-8815.pdf

Dmrecord 350713

Document Type Thesis

Rights Alsharah, Jassem

Type texts

Source University of Southern California (contributing entity), University of Southern California Dissertations and Theses (collection)

Access Conditions The author retains rights to his/her dissertation, thesis or other graduate work according to U.S. copyright law. Electronic access is being provided by the USC Libraries in agreement with the a...

Repository Name University of Southern California Digital Library

Repository Location USC Digital Library, University of Southern California, University Park Campus MC 2810, 3434 South Grand Avenue, 2nd Floor, Los Angeles, California 90089-2810, USA