Measuring impact of systematic reviews using individual participant data: evidence from clinical guidelines

Article type
Authors
Vale C1, Rydzewska L1, Stewart L1, Rovers M2, Emberson J1, Gueyffier F3
1Cochrane IPD Meta-analysis Methods Group, UK
2Cochrane IPD Meta-analysis Methods Group, The Netherlands
3Cochrane IPD Meta-analysis Methods Group, France
Abstract
Background: Systematic reviews (SRs) based on individual participant data (IPD) are often referred to as the gold standard due to improved precision and reliability. Furthermore, IPD SRs may identify treatment by participant subgroup interactions, enabling treatments to be better targeted. This gives IPD SRs enormous potential to influence clinical guidelines. However, uptake by guideline developers, as Level 1 evidence, is unclear.

Objectives: We aimed to assess the impact of IPD SRs of interventions on clinical guidelines across a variety of healthcare areas.

Methods: A sample of IPD SRs published between 2008 and 2010 that evaluated treatment interventions across a number of healthcare areas was identified, largely from records kept by the Cochrane IPD Meta-analysis Methods Group. Relevant clinical guidelines published or revised since 2010 were searched for citations of these IPD SRs. Details of specific recommendations based on results of the IPD SRs and details of citations of any SRs of aggregate data were also collected.

Results: 30 eligible IPD SRs in a number of clinical areas including cancer, cardiovascular disease, and epilepsy were identified and included in the study. 227 potentially relevant clinical guidelines based on disease or treatment types were identified from 4 sources. Preliminary findings are based on 4 IPD SRs in cancer, for which 65 relevant guidelines had been identified. Each IPD SR had been cited in guidelines (2–5 citations per IPD SR), with time from publication to inclusion in a guideline ranging from 6–18 m. However, only 14 guidelines (22%) had cited a relevant IPD Sr. Further results based on all 30 IPD SRs will be presented.

Conclusions: Results of this study will help to guide both those conducting IPD SRs, as well as guideline developers, regarding how best to use IPD SRs to inform guidelines and thus impact on clinical practice.