Factors Associated With Successful Publication for Systematic Review Protocol Registration: an Analysis of 397 Registered Protocols.

Abstract 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. Our models of multivariable logistic regression analysis revealed that two main factors impact the publication outcome: updated protocol status of the published review paper (OR: 1.7, 95% CI: 1.0-2.8, p=0.037) and external funding (OR: 2.1, 95% CI: 1.2-3.8, p=0.01). However, corresponding authors’ location in developed countries (OR: 1.7, 95% CI: 0.8-3.4, p=0.139) and English-speaking countries (OR: 1.5, 95% CI: 0.9-2.6, p=0.1) were insignificant determinants.Conclusion: Meta-analyses continue to be on top of the evidence hierarchy, rendering them the key to informed clinical decision-making. Therefore, more attention should be paid to the methodological quality of this type of publication.