The reporting of safety among drug systematic reviews was poor before the implementation of the PRISMA harms checklist.

Objectives: To examine, through a cross-sectional survey, how well safety information was reported among drug systematic reviews predating PRISMA harms checklist and explore factors associated with better reporting.

Study Design And Setting: We searched PubMed to identify all systematic reviews published in the Cochrane Database of Systematic Review or the core clinical journals in 2015, one year before the PRISMA harms checklist was published. We randomly selected, in a 1:1 ratio, Cochrane and non-Cochrane systematic reviews assessing drug effects (including both efficacy and safety). We used the PRISMA harms checklist published in 2016 to assess the quality of reporting of drug safety information. Multivariable linear regression analyses were used to explore the association of six prespecified variables with more complete reporting of PRISMA harms items.

Results: We included 120 systematic reviews, including 60 Cochrane and 60 non-Cochrane reviews. Scores on the PRISMA harms checklist (23 items) were low (median 4, [first, third quartile: 2, 6]), with no difference between Cochrane and non-Cochrane reviews (4.5 [2, 7] vs. 4 [2.5, 5]; P = 0.29). Among all eligible reviews, only one item (i.e., state conclusions in coherence with the review findings) was reported adequately (proportion of adherence 81.6%); proportion of reporting for other items ranged from 1.7% to 68.3%. The four essential reporting items from PRISMA harms checklist were also poorly complied (proportion of adherence ranged from 1.7% to 9.2%). Multivariable linear regression analyses found no significant associations between any study characteristic and reporting on the PRISMA harms, likely because of limited variability in scores across studies.

Conclusions: The reporting of safety information was poor both for Cochrane and non-Cochrane drug systematic reviews predating PRISMA harms checklist. The findings suggested a strong need to use the PRISMA harms checklist for reporting safety among drug systematic reviews.