Assessment of the abstract reporting of systematic reviews of dose-response meta-analysis: a literature survey

Background There is an increasing number of published systematic reviews (SR) of dose-response meta-analyses (DRMAs) over the past decades. However, the quality of abstract reporting of these SR-DRMAs remains to be understood. We conducted a literature survey to investigate the abstract reporting of SR-DRMAs. Methods Medline, Embase, and Wiley online Library were searched for eligible SR-DRMAs. The reporting quality of SR-DRMAs was assessed by the modified PRISMA-for-Abstract checklist (14 items). We summarized the adherence rate of each item and categorized them as well complied (adhered by 80% or above), moderately complied (50 to 79%), and poorly complied (less than 50%). We used total score to reflect the abstract quality and regression analysis was employed to explore the potential influence factors for it. Results We included 529 SR-DRMAs. Eight of 14 items were moderately (3 items) or poorly complied (5 items) while only 6 were well complied by these SR-DRMAs. Most of the SR-DRMAs failed to describe the methods for risk of bias assessment (30.2, 95% CI: 26.4, 34.4%) and the results of bias assessment (48.8, 95% CI: 44.4, 53.1%). Few SR-DRMAs reported the funding (2.3, 95% CI: 1.2, 3.9%) and registration (0.6, 95% CI: 0.1, 1.6%) information in the abstract. Multivariable regression analysis suggested word number of abstracts [> 250 vs. ≤ 250 (estimated ß = 0.31; 95% CI: 0.02, 0.61; P = 0.039)] was positively associated with the abstract reporting quality. Conclusion The abstract reporting of SR-DRMAs is suboptimal, substantial effort is needed to improve the reporting. More word number may benefit for the abstract reporting. Given that reporting of abstract largely depends on the reporting and conduct of the SR-DRMA, review authors should also focus on the completeness of SR-DRMA itself.