Reporting quality of systematic reviews of interventions aimed at improving vaccination coverage: compliance with PRISMA guidelines.

Systematic reviews have become increasingly important for informing clinical practice and policy; however, little is known about the reporting characteristics and quality of SRs of interventions to improve immunization coverage in different settings. The aim of this study was to assess the reporting quality of systematic reviews of interventions aimed at improving vaccination coverage using the recommended Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) guideline.PubMed and Cochrane Library were searched to identify SRs of interventions to improve immunization coverage, indexed up to May 2016. Two authors independently screened the search output, assessed study eligibility, and extracted data from eligible SRs using a 27-item data collection form derived from PRISMA. Discrepancies in reviews assessments were resolved by discussion and consensus.A total of 57 reviews were included in this study with a mean percentage of applicable PRISMA items that were met across all studies of 66% (range 19-100%) and median compliance of 70%. 39 out of the 57 reviews were published after the release of the PRISMA statement in 2009. Highest compliance was observed in items related to the "description of rational", "description of eligibility criteria", "synthesis of results" and "provision of a general interpretation of the results" (items #3, #6, #14 and #26, respectively). Compliance was poorest in the items "describing summary of evidence" (item 24, 19%), "describing indication of review protocol and registration" (item 5, 26%) and "describing results of risk of bias across studies (item 22, 33%).The overall reporting quality of systematic reviews of interventions to improve vaccination coverage requires significant improvement. There remains a need for additional research targeted at addressing potential barriers to compliance and strategies to improve compliance with PRISMA guideline.