Reporting guidelines on how to write a complete and transparent abstract for overviews of systematic reviews of health care interventions

Objective: An overview of systematic reviews (OoSRs) is a study designed to offer a broad view of evidence from existing systematic reviews (SRs). The abstract is an important part of an OoSRs as it can determine whether reading the full text is of interest. The aim of this article is to offer guidelines to promote transparent and sufficient reporting in abstracts of OoSRs of health care interventions.

Study design and setting: The items were developed by combining key features from abstracts of OoSRs, PRISMA for abstracts, and our published reporting guidelines for OoSRs. The initial version was distributed to experts to give feedback; pilot testing by a group of researchers followed. The refined checklist was applied by two reviewers independently in a sample of 40 abstracts.

Results: The developed instrument "Preferred Reporting Items for OoSRs abstracts" (PRIO for abstracts) consists of six sections with 15 topics including 20 items in total. The mean inter-rater reliability was 0.87 (95% confidence interval: 0.82, 0.92). An explanation and at least one published example of good reporting per item are provided.

Conclusion: This instrument will assist authors in writing transparent and informative abstracts for OoSRs and can be adopted by journals that publish OoSRs.