Uptake of systematic reviews and meta-analyses based on individual participant data in clinical practice guidelines: descriptive study

OBJECTIVE To establish the extent to which systematic reviews and meta-analyses of individual participant data (IPD) are being used to inform the recommendations included in published clinical guidelines. DESIGN Descriptive study. SETTING Database maintained by the Cochrane IPD Meta-analysis Methods Group, supplemented by records of published IPD meta-analyses held in a separate database. POPULATION A test sample of systematic reviews of randomised controlled trials that included a meta-analysis of IPD, and a separate sample of clinical guidelines, matched to the IPD meta-analyses according to medical condition, interventions, populations, and dates of publication. DATA EXTRACTION Descriptive information on each guideline was extracted along with evidence showing use or critical appraisal, or both, of the IPD meta-analysis within the guideline; recommendations based directly on its findings and the use of other systematic reviews in the guideline. RESULTS Based on 33 IPD meta-analyses and 177 eligible, matched clinical guidelines there was evidence that IPD meta-analyses were being under-utilised. Only 66 guidelines (37%) cited a matched IPD meta-analysis. Around a third of these (n=22, 34%) had critically appraised the IPD meta-analysis. Recommendations based directly on the matched IPD meta-analyses were identified for only 18 of the 66 guidelines (27%). For the guidelines that did not cite a matched IPD meta-analysis (n=111, 63%), search dates had preceded the publication of the IPD meta-analysis in 23 cases (21%); however, for the remainder, there was no obvious reasons why the IPD meta-analysis had not been cited. CONCLUSIONS Our results indicate that systematic reviews and meta-analyses based on IPD are being under-utilised. Guideline developers should routinely seek good quality and up to date IPD meta-analyses to inform guidelines. Increased use of IPD meta-analyses could lead to improved guidelines ensuring that routine patient care is based on the most reliable evidence available.