Changing patterns in reporting and sharing of review data in systematic reviews with meta-analysis of the effects of interventions: a meta-research study

Objectives To examine changes in completeness of reporting and frequency of sharing data, analytic code and other review materials in systematic reviews (SRs) over time; and factors associated with these changes. Design Cross-sectional meta-research study. Sample A random sample of 300 SRs with meta-analysis of aggregate data on the effects of a health, social, behavioural or educational intervention, which were indexed in PubMed, Science Citation Index, Social Sciences Citation Index, Scopus and Education Collection in November 2020. Analysis/Outcomes The extent of complete reporting and frequency of sharing review materials in these reviews were compared with 110 SRs indexed in February 2014. Associations between completeness of reporting and various factors (e.g. self-reported use of reporting guidelines, journal’s data sharing policies) were examined by calculating risk ratios (RR) and 95% confidence intervals (CI). Results Several items were reported sub-optimally among 300 SRs from 2020, such as a registration record for the review (38%), a full search strategy for at least one database (71%), methods used to assess risk of bias (62%), methods used to prepare data for meta-analysis (34%), and funding source for the review (72%). Only a few items not already reported at a high frequency in 2014 were reported more frequently in 2020. There was no evidence that reviews using a reporting guideline were more completely reported than reviews not using a guideline. Reviews published in 2020 in journals that mandated either data sharing or inclusion of Data Availability Statements were more likely to share their review materials (e.g. data, code files) (18% vs 2%). Conclusion Incomplete reporting of several recommended items for systematic reviews persists, even in reviews that claim to have followed a reporting guideline. Data sharing policies of journals potentially encourage sharing of review materials. SUMMARY BOX #### What is already known on this topic What is already known on this topic #### What this study adds What this study adds ### Competing Interest Statement The authors have declared no competing interest. ### Funding Statement This research is funded by the Australian Research Council Discovery Early Career Researcher Award (DE200101618), held by MJP; JEM is supported by the National Health and Medical Research Council Career Development Fellowship (APP1143429); DM is supported in part as the University Research Chair, University of Ottawa; NRH is funded by the Alexander von Humboldt Experienced Researcher Fellowship; DGH is supported by the Australian Commonwealth Government Research Training Program Scholarship; RK is supported by the Monash Graduate Scholarship and the Monash International Tuition Scholarship. The funders had no role in the study design, decision to publish, or preparation of the manuscript. ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines and uploaded the relevant EQUATOR Network research reporting checklist(s) and other pertinent material as supplementary files, if applicable. Yes All datasets and analytic code can be found on the Open Science Framework (DOI: 10.17605/OSF.IO/JSP9T).