Preferred reporting items for overviews of systematic reviews including harms checklist: a pilot tool to be used for balanced reporting of benefits and harms

An overview of systematic reviews (OoSRs) is a study designed to synthesize multiple evidence from existing systematic reviews on a specific domain. The aim of this paper was to offer a pilot version checklist with Preferred Reporting Items for OoSRs (PRIO-harms) to promote a more balanced reporting of benefits and harms in OoSRs of health care interventions. The included items were developed by combining key features from health care OoSRs designs with recommendations from statements of other relevant checklists and pertinent methodological review articles. Two raters independently used the PRIO-harms checklist to assess a sample of 20 OoSRs. The PRIO-harms tool consists of a 27-item (56 (sub-)items in total) checklist and is accompanied by a five-stage process flow diagram (identification, screening, eligibility, inclusion, and separation of relevant studies). The mean interrater reliability (Gwet's AC1 statistic) between reviewers was 0.90 (95% confidence interval: 0.88, 0.92) indicating a very good agreement. The PRIO-harms tool can be used in every OoSRs that addresses health care interventions. This instrument will assist overview authors to improve completeness and transparency of research reporting with emphasis on harms. However, it might benefit from critical review and further validation from experts and research teams that produce OoSRs.