The independent and joint risks of alcohol consumption, smoking, and excess weight on morbidity and mortality: a systematic review and meta-analysis exploring synergistic associations

OBJECTIVE

Alcohol consumption, smoking, and excess weight independently increase the risk of morbidity/mortality. Less is known about how they interact. This research aims to quantify the independent and joint associations of these exposures across health outcomes and identify whether these associations are synergistic.

STUDY DESIGN

The protocol for this systematic review and meta-analysis was pre-registered (PROSPERO CRD42021231443).

METHODS

Medline and Embase were searched between 1 January 2010 and 9 February 2022. Eligible peer-reviewed observational studies had to include adult participants from Organisation for Co-Operation and Development countries and report independent and joint associations between at least two eligible exposures (alcohol, smoking, and excess weight) and an ICD-10 outcome (or equivalent). For all estimates, we calculated the synergy index (SI) to identify whether joint associations were synergistic. Meta-analyses were conducted for outcomes with sufficiently homogenous data.

RESULTS

The search returned 26,290 studies, of which 98 were included. Based on 138,130 participants, the combined effect (SI) of alcohol and smoking on head and neck cancer death/disease was 3.78 times greater than the additive effect of each exposure (95% confidence interval [CI] = 2.61, 5.48). Based on 2,603,939 participants, the combined effect of alcohol and excess weight on liver disease/death was 1.55 times greater than the additive effect of each exposure (95% CI = 1.33, 1.82).

CONCLUSION

Synergistic associations suggest the true population-level risk may be underestimated. In the absence of bias, individuals with multiple risks would experience a greater absolute risk reduction from an intervention that targets a single exposure than individuals with a single risk.

Factors associated with successful publication for systematic review protocol registration: an analysis of 397 registered protocols

BACKGROUND

Meta-analyses are on top of the evidence-based medicine pyramid, yet many of them are not completed after they are begun. Many factors impacting the publication of meta-analysis works have been discussed, and their association with publication likelihood has been investigated. These factors include the type of systematic review, journal metrics, h-index of the corresponding author, country of the corresponding author, funding sources, and duration of publication. In our current review, we aim to investigate these various factors and their impact on the likelihood of publication. A comprehensive review of 397 registered protocols retrieved from five databases was performed to investigate the different factors that might affect the likelihood of publication. These factors include the type of systematic review, journal metrics, h-index of the corresponding author, country of the corresponding author, funding sources, and duration of publication.

RESULTS

We found that corresponding authors in developed countries and English-speaking countries had higher likelihoods of publication: 206/320 (p = 0.018) and 158/236 (p = 0.006), respectively. Factors affecting publications are the countries of corresponding author (p = 0.033), whether they are from developed countries (OR: 1.9, 95% CI: 1.2-3.1, p = 0.016), from English-speaking countries (OR: 1.8, 95% CI: 1.2-2.7, p = 0.005), update status of the protocol (OR: 1.6, 95% CI: 1.0-2.6, p = 0.033), and external funding (OR: 1.7, 95% CI: 1.1-2.7, p = 0.025). Multivariable regression retains three variables as significant predictors for the publication of a systematic review: whether it is the corresponding author from developed countries (p = 0.013), update status of the protocol (p = 0.014), and external funding (p = 0.047).

CONCLUSION

Being on top of the evidence hierarchy, systematic review and meta-analysis are the keys to informed clinical decision-making. Updating protocol status and external funding are significant influences on their publications. More attentions should be paid to the methodological quality of this type of publication.

Predictors of Higher Quality of Systematic Reviews Addressing Nutrition and Cancer Prevention

Systematic reviews/meta-analyses (SR/MAs) are considered a reliable source of information in healthcare. We aimed to explore the association of several characteristics of SR/MAs addressing nutrition in cancer prevention and their quality/risk of bias (using assessments from AMSTAR-2 and ROBIS tools). The analysis included 101 SR/MAs identified in a systematic survey. Associations of each specified characteristic (e.g., information about the protocol, publication year, reported use of GRADE, or other methods for assessing overall certainty of evidence) with the number of AMSTAR-2 not met (‘No’ responses) and the number of ROBIS items met (‘Probably Yes’ or “Yes’ responses) were examined. Poisson regression was used to identify predictors of the number of ‘No’ answers (indicating lower quality) for all AMSTAR-2 items and the number of ‘Yes’ or ‘Probably Yes’ answers (indicating higher quality/lower concern for bias) for all ROBIS items. Logistic regression was used to identify variables associated with at least one domain assessed as ‘low concern for bias’ in the ROBIS tool. In multivariable analysis, SR/MAs not reporting use of any quality/risk of bias assessment instrument for primary studies were associated with a higher number of ‘No’ answers for all AMSTAR-2 items (incidence rate ratio (IRR) 1.26, 95% confidence interval (CI) 1.09–1.45), and a lower number of ‘Yes’ or ‘Probably Yes’ answers for all ROBIS items (IRR 0.76, 95% CI 0.66–0.87). Providing information about the protocol and search for unpublished studies was associated with a lower number of ‘No’ answers (IRR 0.73, 95% CI 0.56–0.97 and IRR 0.75, 95% CI 0.59–0.95, respectively) and a higher number of ‘Yes’ or ‘Probably Yes’ answers (IRR 1.43, 95% CI 1.17–1.74 and IRR 1.28, 95% CI 1.07–1.52, respectively). Not using at least one quality/risk of bias assessment tool for primary studies within an SR/MA was associated with lower odds that a study would be assessed as ‘low concern for bias’ in at least one ROBIS domain (odds ratio 0.061, 95% CI 0.007–0.527). Adherence to methodological standards in the development of SR/MAs was associated with a higher overall quality of SR/MAs addressing nutrition for cancer prevention.

Development of an efficient search filter to retrieve systematic reviews from PubMed

Objective:

Locating systematic reviews is essential for clinicians and researchers when creating or updating reviews and for decision-making in health care. This study aimed to develop a search filter for retrieving systematic reviews that improves upon the performance of the PubMed systematic review search filter.

Methods:

Search terms were identified from abstracts of reviews published in Cochrane Database of Systematic Reviews and the titles of articles indexed as systematic reviews in PubMed. Both the precision of the candidate terms and the number of systematic reviews retrieved from PubMed were evaluated after excluding the subset of articles retrieved by the PubMed systematic review filter. Terms that achieved a precision greater than 70% and relevant publication types indexed with MeSH terms were included in the filter search strategy.

Results:

The search strategy used in our filter added specific terms not included in PubMed's systematic review filter and achieved a 61.3% increase in the number of retrieved articles that are potential systematic reviews. Moreover, it achieved an average precision that is likely greater than 80%.

Conclusions:

The developed search filter will enable users to identify more systematic reviews from PubMed than the PubMed systematic review filter with high precision.

Assessing the compliance of systematic review articles published in leading dermatology journals with the PRISMA statement guidelines: A systematic review

Background

Reporting quality of systematic reviews and meta-analyses is of critical importance in dermatology because of their key role in informing health care decisions.

Objective

To assess the compliance of systematic reviews and meta-analyses in leading dermatology journals with the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) statement guidelines.

Methods

This review was carried out in accordance with PRISMA guidelines. Included studies were reviews published across 6 years in the top 4 highest-impact-factor dermatology journals of 2017. Records and full texts were screened independently. Data analysis was conducted with univariate multivariable linear regression. The primary outcome was to assess the compliance of systematic reviews and meta-analyses in leading dermatology journals with the PRISMA statement.

Results

A total of 166 studies were included and mean PRISMA compliance across all articles was 73%. Compliance significantly improved over time (β = .016; P = <.001). The worst reported checklist item was item 5 (reporting on protocol existence), with a compliance of 15% of articles.

Conclusion

PRISMA compliance within leading dermatology journals could be improved; however, it is steadily improving.

Worldwide production on sleep apnea from 2009-2018. Analysis of the ability to secure funding and international collaboration networks

BACKGROUND

Obstructive sleep apnea (OSA) is an emerging health problem, but information on scientific production in this subject area is scarce. We aim to evaluate the scientific production on OSA from 2009 to 2018 to illustrate its worldwide distribution, topic areas, and ability to secure funding, as well as to describe international collaboration networks in this field.

METHODS

Articles published between 2009 and 2018 were extracted from the Science Citation Index Expanded via Web of Science (WoS) using the search term "obstructive sleep apn*". Publication year, number and country of authors, journal, subject category, key words, funding source and number of citations received were recorded. We also conducted network analyses for key words and international collaboration.

RESULTS

12,666 articles on OSA were located, which had increased from 895 documents in 2009 to 1592 in 2018. The progressive growth in scientific production on OSA had outpaced the growth rate of total WoS production since 2012.50% of the articles declared some type of funding, with a citation index higher than manuscripts that were not funded. The manuscripts were distributed in journals from 135 subject categories of the WoS, and keyword distribution showed a dispersed pattern with a high number of nodes. The international collaboration rate was 18.2%, and the country network showed the United States as the hegemonic node.

CONCLUSION

World production on OSA has grown at a higher rate than global production and shows notable thematic dispersion as well as a high ability to secure funding, which increases its impact.

Inexpensive Systemic Inflammatory Biomarkers in Ovarian Cancer: An Umbrella Systematic Review of 17 Prognostic Meta-Analyses

The association of several inflammation-based biomarkers [lymphocyte-to-monocyte, neutrophil-to-lymphocyte, and platelet-to-lymphocyte ratios (LMR, NLR, and PLR, respectively)] with the survival of epithelial ovarian cancer (EOC) patients has been extensively investigated in several systematic reviews and meta-analyses (MAs) of observational studies. The aim of this umbrella systematic review is to appraise all available results in published MAs that explored the association between these biomarkers and EOC outcomes. An umbrella systematic review of the current evidence for systemic inflammatory biomarkers in the peripheral blood of EOC patients was performed by searching several databases including PubMed/Medline and Web of Science. The quality of the MAs was appraised using the AMSTAR-2 tool as well as other qualitative criteria. The evidence was graded from convincing (Class I) to weak (Class IV). Our umbrella review appraised 17 MAs of retrospective studies (range: 7-16) with a number of enrolled patients ranging from 1,636 to 4,910 patients in each MA. All these MAs demonstrated that pretreatment high NLR and PLR, as well as low LMR, were independent predictors of poor overall survival and progression-free survival in EOC. Nearly all published MAs were conducted by Chinese researchers (16/17) and were redundant in their character. Another issue in these MAs is the absence of prior PROSPERO database registration as well as the earlier exclusion of the gray literature. On the other hand, Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) and Meta-analyses Of Observational Studies in Epidemiology (MOOSE)-based reporting guidelines were used in nine out of the 17 MAs. A good number of MAs have transparently provided funding acknowledgment. The AMSTAR-2-based assessment showed low quality in 11 out of the 17 reviewed MAs. This negative rating was largely due to the absence of critical domains. Finally, all evaluated MAs were rated as Class III or IV (suggestive and weak, respectively). Despite the power of MAs in increasing sampling and precision, the quality of the current non-randomized evidence on this topic is still weak.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO, identifier CRD42020201493.

Financial conflicts of interest in systematic reviews: associations with results, conclusions, and methodological quality

BACKGROUND

Financial conflicts of interest in systematic reviews (e.g. funding by drug or device companies or authors' collaboration with such companies) may impact on how the reviews are conducted and reported.

OBJECTIVES

To investigate the degree to which financial conflicts of interest related to drug and device companies are associated with results, conclusions, and methodological quality of systematic reviews.

SEARCH METHODS

We searched PubMed, Embase, and the Cochrane Methodology Register for studies published up to November 2016. We also read reference lists of included studies, searched grey literature sources, and Web of Science for studies citing the included studies.

SELECTION CRITERIA

Eligible studies were studies that compared systematic reviews with and without financial conflicts of interest in order to investigate differences in results (estimated treatment effect and frequency of statistically favourable results), frequency of favourable conclusions, or measures of methodological quality of the review (e.g. as evaluated on the Oxman and Guyatt index).

DATA COLLECTION AND ANALYSIS

Two review authors independently determined the eligibility of studies, extracted data, and assessed risk of bias. We synthesised the results of each study relevant to each of our outcomes. For meta-analyses, we used Mantel-Haenszel random-effects models to estimate risk ratios (RR) with 95% confidence intervals (CIs), with RR > 1 indicating that systematic reviews with financial conflicts of interest more frequently had statistically favourable results or favourable conclusions, and had lower methodological quality. When a quantitative synthesis was considered not meaningful, results from individual studies were summarised qualitatively.

MAIN RESULTS

Ten studies with a total of 995 systematic reviews of drug studies and 15 systematic reviews of device studies were included. We assessed two studies as low risk of bias and eight as high risk, primarily because of risk of confounding. The estimated treatment effect was not statistically significantly different for systematic reviews with and without financial conflicts of interest (Z-score: 0.46, P value: 0.64; based on one study of 14 systematic reviews which had a matched design, comparing otherwise similar systematic reviews). We found no statistically significant difference in frequency of statistically favourable results for systematic reviews with and without financial conflicts of interest (RR: 0.84, 95% CI: 0.62 to 1.14; based on one study of 124 systematic reviews). An analysis adjusting for confounding due to methodological quality (i.e. score on the Oxman and Guyatt index) provided a similar result. Systematic reviews with financial conflicts of interest more often had favourable conclusions compared with systematic reviews without (RR: 1.98, 95% CI: 1.26 to 3.11; based on seven studies of 411 systematic reviews). Similar results were found in two studies with a matched design, which therefore had a reduced risk of confounding. Systematic reviews with financial conflicts of interest tended to have lower methodological quality compared with systematic reviews without financial conflicts of interest (RR for 11 dimensions of methodological quality spanned from 1.00 to 1.83). Similar results were found in analyses based on two studies with matched designs.

AUTHORS' CONCLUSIONS

Systematic reviews with financial conflicts of interest more often have favourable conclusions and tend to have lower methodological quality than systematic reviews without financial conflicts of interest. However, it is uncertain whether financial conflicts of interest are associated with the results of systematic reviews. We suggest that patients, clinicians, developers of clinical guidelines, and planners of further research could primarily use systematic reviews without financial conflicts of interest. If only systematic reviews with financial conflicts of interest are available, we suggest that users read the review conclusions with skepticism, critically appraise the methods applied, and interpret the review results with caution.

Gambling Research and Funding Biases

A recent systematic review of the responsible gambling research suggests that there are no significant differences between gambling industry and non-industry funded research with regard to research design and outcomes. This study empirically synthesizes the outcomes of a larger sample of the scientific gambling literature to determine the generalizability of these original results. Our goal was to determine the extent to which funding sources might differentially influence characteristics of research design and outcomes. We conducted a comprehensive review of 18 research databases and examined studies published between January 2008 and August 2018. For four gambling-related journals, we reviewed all of the available studies. For 14 addiction-related journals, we examined only studies that examined gambling-related outcomes. To be included in this study, publications had to be quantitative and include a clear gambling-related hypothesis. After retrieving 1731 gambling studies, we applied the inclusion criteria and retained 720 studies for our final analytic sample. We used hypothesis confirmation and funding source information to determine the presence or absence of funding bias. Gambling industry funded studies were no more likely than studies not funded by the gambling industry to report either confirmed, partially confirmed, or rejected hypotheses. Nonetheless, studies funded by the gambling industry were more likely than other types of funding sources to include a conflict of interest statement. Studies with disclosed funding sources were more likely than those with undisclosed funding sources to include a conflict of interest statement. These findings highlight the importance of transparency and disclosure during research dissemination.

Bibliometric Analysis of Journals in the Field of Endoscopic Endonasal Surgery for Pituitary Adenomas

Endoscopic endonasal surgery for pituitary adenomas is being performed more frequently worldwide in the recent years. This first bibliometric analysis was conducted aiming to have a microscopic view of research activities about endoscopic endonasal surgery for pituitary adenomas. The original articles about endoscopic endonasal surgery for pituitary adenomas were extracted from the Web of Science (WoS) and analyzed concerning their distributions. We also explored the potential correlations between publications of different countries and their gross domestic product (GDP) via Pearson correlation test. The total number of original articles retrieved from WoS was 307 from 1997 to 2017. The number of original articles published in the last decade has increased by 530.95% compared with that published in the former decade. The United States has published 124 articles (40.391%), followed by Italy with 40 (13.029%) and Japan with 27 articles (8.795%). The journal that published the highest number of original articles was Journal of Neurosurgery with 31 (10.098%), followed by Neurosurgery (n = 23, 7.492%), World Neurosurgery (n = 23, 7.492%), and Neurosurgical Focus (n = 15, 4.886%). There was a strong correlation between publication numbers and GDP of different countries (r = 0.889, P < 0.001). There is a skyrocket trend of endoscopic endonasal surgery for pituitary adenomas during the last 2 decades, and countries with high GDP tend to make more contributions to this field.

Evaluating characteristics of PROSPERO records as predictors of eventual publication of non-Cochrane systematic reviews: a meta-epidemiological study protocol

BACKGROUND

Epidemiology and the reporting characteristics of systematic reviews (SRs) and meta-analyses (MAs) are well known. However, no study has analyzed the influence of protocol features on the probability that a study's results will be finally reported, thereby indirectly assessing the reporting bias of International Prospective Register of Systematic Reviews (PROSPERO) registration records.

OBJECTIVE

The objective of this study is to explore which factors are associated with a higher probability that results derived from a non-Cochrane PROSPERO registration record for a systematic review will be finally reported as an original article in a scientific journal.

METHODS/DESIGN

The PROSPERO repository will be web scraped to automatically and iteratively obtain all completed non-Cochrane registration records stored from February 2011 to December 2017. Downloaded records will be screened, and those with less than 90% fulfilled or are duplicated (i.e., those sharing titles and reviewers) will be excluded. Manual and human-supervised automatic methods will be used for data extraction, depending on the data source (fields of PROSPERO registration records, bibliometric databases, etc.). Records will be classified into published, discontinued, and abandoned review subgroups. All articles derived from published reviews will be obtained through multiple parallel searches using the full protocol "title" and/or "list reviewers" in MEDLINE/PubMed databases and Google Scholar. Reviewer, author, article, and journal metadata will be obtained using different sources. R and Python programming and analysis languages will be used to describe the datasets; perform text mining, machine learning, and deep learning analyses; and visualize the data. We will report the study according to the recommendations for meta-epidemiological studies adapted from the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement for SRs and MAs.

DISCUSSION

This meta-epidemiological study will explore, for the first time, characteristics of PROSPERO records that may be associated with the publication of a completed systematic review. The evidence may help to improve review workflow performance in terms of research topic selection, decision-making regarding team selection, planning relationships with funding sources, implementing literature search strategies, and efficient data extraction and analysis. We expect to make our results, datasets, and R and Python code scripts publicly available during the third quarter of 2018.

The differential impact of scientific quality, bibliometric factors, and social media activity on the influence of systematic reviews and meta-analyses about psoriasis

Researchers are increasingly using on line social networks to promote their work. Some authors have suggested that measuring social media activity can predict the impact of a primary study (i.e., whether or not an article will be highly cited). However, the influence of variables such as scientific quality, research disclosures, and journal characteristics on systematic reviews and meta-analyses has not yet been assessed. The present study aims to describe the effect of complex interactions between bibliometric factors and social media activity on the impact of systematic reviews and meta-analyses about psoriasis (PROSPERO 2016: CRD42016053181). Methodological quality was assessed using the Assessing the Methodological Quality of Systematic Reviews (AMSTAR) tool. Altmetrics, which consider Twitter, Facebook, and Google+ mention counts as well as Mendeley and SCOPUS readers, and corresponding article citation counts from Google Scholar were obtained for each article. Metadata and journal-related bibliometric indices were also obtained. One-hundred and sixty-four reviews with available altmetrics information were included in the final multifactorial analysis, which showed that social media and impact factor have less effect than Mendeley and SCOPUS readers on the number of cites that appear in Google Scholar. Although a journal's impact factor predicted the number of tweets (OR, 1.202; 95% CI, 1.087-1.049), the years of publication and the number of Mendeley readers predicted the number of citations in Google Scholar (OR, 1.033; 95% CI, 1.018-1.329). Finally, methodological quality was related neither with bibliometric influence nor social media activity for systematic reviews. In conclusion, there seems to be a lack of connectivity between scientific quality, social media activity, and article usage, thus predicting scientific success based on these variables may be inappropriate in the particular case of systematic reviews.

Is the information of systematic reviews published in nursing journals up-to-date? a cross-sectional study

BACKGROUND

An up-to-date systematic review is important for researchers to decide whether to embark on new research or continue supporting ongoing studies. The aim of this study is to examine the time taken between the last search, submission, acceptance and publication dates of systematic reviews published in nursing journals.

METHODS

Nursing journals indexed in Journal Citation Reports were first identified. Thereafter, systematic reviews published in these journals in 2014 were extracted from three databases. The quality of the systematic reviews were evaluated by the AMSTAR. The last search, submission, acceptance, online publication, full publication dates and other characteristics of the systematic reviews were recorded. The time taken between the five dates was then computed. Descriptive statistics were used to summarize the time differences; non-parametric statistics were used to examine the association between the time taken from the last search and full publication alongside other potential factors, including the funding support, submission during holiday periods, number of records retrieved from database, inclusion of meta-analysis, and quality of the review.

RESULTS

A total of 107 nursing journals were included in this study, from which 1070 articles were identified through the database search. After screening for eligibility, 202 systematic reviews were included in the analysis. The quality of these reviews was low with the median score of 3 out of 11. A total of 172 (85.1%), 72 (35.6%), 153 (75.7%) and 149 (73.8%) systematic reviews provided their last search, submission, acceptance and online published dates respectively. The median numbers of days taken from the last search to acceptance and to full publication were, respectively, 393 (IQR: 212-609) and 669 (427-915) whereas that from submission to full publication was 365 (243-486). Moreover, the median number of days from the last search to submission and from submission to online publication were 167.5 (53.5-427) and 153 (92-212), respectively. No significant association were revealed between the time lag and those potential factors.

CONCLUSION

The median time from the last search to acceptance for systematic reviews published in nursing journals was 393 days. Readers for systematic reviews are advised to check the time taken from the last search date of the reviews in order to ensure that up-to-date evidence is consulted for effective clinical decision-making.

Most systematic reviews of high methodological quality on psoriasis interventions are classified as high risk of bias using ROBIS tool

OBJECTIVES

No gold standard exists to assess methodological quality of systematic reviews (SRs). Although Assessing the Methodological Quality of Systematic Reviews (AMSTAR) is widely accepted for analyzing quality, the ROBIS instrument has recently been developed. This study aimed to compare the capacity of both instruments to capture the quality of SRs concerning psoriasis interventions.

STUDY DESIGN AND SETTING

Systematic literature searches were undertaken on relevant databases. For each review, methodological quality and bias risk were evaluated using the AMSTAR and ROBIS tools. Descriptive and principal component analyses were conducted to describe similarities and discrepancies between both assessment tools.

RESULTS

We classified 139 intervention SRs as displaying high/moderate/low methodological quality and as high/low risk of bias. A high risk of bias was detected for most SRs classified as displaying high or moderate methodological quality by AMSTAR. When comparing ROBIS result profiles, responses to domain 4 signaling questions showed the greatest differences between bias risk assessments, whereas domain 2 items showed the least.

CONCLUSION

When considering SRs published about psoriasis, methodological quality remains suboptimal, and the risk of bias is elevated, even for SRs exhibiting high methodological quality. Furthermore, the AMSTAR and ROBIS tools may be considered as complementary when conducting quality assessment of SRs.

The influence of the team in conducting a systematic review

There is an increasing body of research documenting flaws in many published systematic reviews' methodological and reporting conduct. When good systematic review practice is questioned, attention is rarely turned to the composition of the team that conducted the systematic review. This commentary highlights a number of relevant articles indicating how the composition of the review team could jeopardise the integrity of the systematic review study and its conclusions. Key biases require closer attention such as sponsorship bias and researcher allegiance, but there may also be less obvious affiliations in teams conducting secondary evidence-syntheses. The importance of transparency and disclosure are now firmly on the agenda for clinical trials and primary research, but the meta-biases that systematic reviews may be at risk from now require further scrutiny.

Author-paper affiliation network architecture influences the methodological quality of systematic reviews and meta-analyses of psoriasis

Moderate-to-severe psoriasis is associated with significant comorbidity, an impaired quality of life, and increased medical costs, including those associated with treatments. Systematic reviews (SRs) and meta-analyses (MAs) of randomized clinical trials are considered two of the best approaches to the summarization of high-quality evidence. However, methodological bias can reduce the validity of conclusions from these types of studies and subsequently impair the quality of decision making. As co-authorship is among the most well-documented forms of research collaboration, the present study aimed to explore whether authors’ collaboration methods might influence the methodological quality of SRs and MAs of psoriasis. Methodological quality was assessed by two raters who extracted information from full articles. After calculating total and per-item Assessment of Multiple Systematic Reviews (AMSTAR) scores, reviews were classified as low (0-4), medium (5-8), or high (9-11) quality. Article metadata and journal-related bibliometric indices were also obtained. A total of 741 authors from 520 different institutions and 32 countries published 220 reviews that were classified as high (17.2%), moderate (55%), or low (27.7%) methodological quality. The high methodological quality subnetwork was larger but had a lower connection density than the low and moderate methodological quality subnetworks; specifically, the former contained relatively fewer nodes (authors and reviews), reviews by authors, and collaborators per author. Furthermore, the high methodological quality subnetwork was highly compartmentalized, with several modules representing few poorly interconnected communities. In conclusion, structural differences in author-paper affiliation network may influence the methodological quality of SRs and MAs on psoriasis. As the author-paper affiliation network structure affects study quality in this research field, authors who maintain an appropriate balance between scientific quality and productivity are more likely to develop higher quality reviews.