Article type
Year
Abstract
Background: Reports of randomized clinical trials (RCTs) do not typically report whether certain categories of participants (e.g. non-compliers, those who withdraw consent) were followed-up for the outcome(s) of interest. It is not clear how systematic reviews (SRs) address this lack of information, i.e. assume they have missing participant data (MPD) or not.
Objectives: To describe how SRs report and handle categories of participants that could be potentially counted as having MPD.
Methods: We included SRs reporting a group-level meta-analysis of a patient-important dichotomous efficacy outcome, with a statistically significant effect estimate. Thirteen reviewers, working in pairs, independently extracted data from eligible SRs. We focused on 10 categories that could be counted as potentially having MPD: 'ineligible participants', 'did not receive any treatment', 'withdrew consent', 'outcome not assessable', 'explained and unexplained lost to follow-up', 'dead', 'experienced adverse events', 'non-compliant', 'discontinued prematurely', and 'cross-over'. We assessed whether the systematic reviewers: 1) planned in the methods section to collect information about those categories; 2) reported in the results section, the number of participants in those categories; and 3) reported on methods for handling MPD in their primary meta-analysis.
Results: We included a random sample of 100 Cochrane and non-Cochrane SRs published in 2012. Tables 1, 2, and 3 report our main findings. Twenty-five per cent of the SRs reported a plan to collect information about the categories of interest in their methods section, whereas 45% reported in their results section the number of participants in those categories. Only 13% reported a method to handle MPD in their primary meta-analyses, which were primarily complete case analysis.
Conclusions: Most SRs do not explicitly report sufficient information on categories of participants that could be potentially counted as having MPD, or handle MPD in their primary meta-analysis.
Objectives: To describe how SRs report and handle categories of participants that could be potentially counted as having MPD.
Methods: We included SRs reporting a group-level meta-analysis of a patient-important dichotomous efficacy outcome, with a statistically significant effect estimate. Thirteen reviewers, working in pairs, independently extracted data from eligible SRs. We focused on 10 categories that could be counted as potentially having MPD: 'ineligible participants', 'did not receive any treatment', 'withdrew consent', 'outcome not assessable', 'explained and unexplained lost to follow-up', 'dead', 'experienced adverse events', 'non-compliant', 'discontinued prematurely', and 'cross-over'. We assessed whether the systematic reviewers: 1) planned in the methods section to collect information about those categories; 2) reported in the results section, the number of participants in those categories; and 3) reported on methods for handling MPD in their primary meta-analysis.
Results: We included a random sample of 100 Cochrane and non-Cochrane SRs published in 2012. Tables 1, 2, and 3 report our main findings. Twenty-five per cent of the SRs reported a plan to collect information about the categories of interest in their methods section, whereas 45% reported in their results section the number of participants in those categories. Only 13% reported a method to handle MPD in their primary meta-analyses, which were primarily complete case analysis.
Conclusions: Most SRs do not explicitly report sufficient information on categories of participants that could be potentially counted as having MPD, or handle MPD in their primary meta-analysis.