Article type
Year
Abstract
Background: A completely specified outcome requires the following five elements: domain (e.g. intraocular pressure (IOP)), specific measurement (e.g. applanation tonometry), specific metric (e.g. change from baseline), method of aggregation (e.g. mean), and time-point (e.g. three months). To perform a meta-analysis of the effect of an intervention, one also needs to know the estimate of treatment effect as well as its precision (e.g. standard error) from each trial. Incomplete reporting of an outcome prevents its full use in a systematic review and meta-analysis, resulting in wasted information.
Objectives: To quantify the proportion of incomplete outcome data reporting for randomized controlled trials (RCTs) of medical interventions for open-angle glaucoma (OAG).
Methods: We searched electronic databases for RCTs of medical interventions for OAG with no restrictions with respect to date or language. Two individuals independently screened records and abstracted data. For this project, we analyzed the completeness of IOP and visual field (VF) data in included trials. Discrepancies were resolved by consensus. We used the most complete reporting of outcomes for each RCT.
Results: We identified 417 trials with 65,452 participants as of May 2014, of which 406 (97%) trials and 87 (21%) trials reported IOP and VF as an outcome, respectively (Table 1). Data from about 56,000 participants from 356 trials was 'wasted' due to lack of VF outcome data (Table 1). For IOP, a surrogate outcome, data from about 10,000 participants from 67 trials was 'wasted' due to lack of IOP outcome data.
Conclusions: Only a small proportion of all identified trials reported complete VF data for meta-analysis, a patient-centered outcome. Investigators have a moral obligation to their participants and colleagues to be more vigilant about complete reporting outcomes and not 'waste' data. The comparative effectiveness of glaucoma interventions could be better determined with more complete reporting on VF and other patient-centered outcomes.
Objectives: To quantify the proportion of incomplete outcome data reporting for randomized controlled trials (RCTs) of medical interventions for open-angle glaucoma (OAG).
Methods: We searched electronic databases for RCTs of medical interventions for OAG with no restrictions with respect to date or language. Two individuals independently screened records and abstracted data. For this project, we analyzed the completeness of IOP and visual field (VF) data in included trials. Discrepancies were resolved by consensus. We used the most complete reporting of outcomes for each RCT.
Results: We identified 417 trials with 65,452 participants as of May 2014, of which 406 (97%) trials and 87 (21%) trials reported IOP and VF as an outcome, respectively (Table 1). Data from about 56,000 participants from 356 trials was 'wasted' due to lack of VF outcome data (Table 1). For IOP, a surrogate outcome, data from about 10,000 participants from 67 trials was 'wasted' due to lack of IOP outcome data.
Conclusions: Only a small proportion of all identified trials reported complete VF data for meta-analysis, a patient-centered outcome. Investigators have a moral obligation to their participants and colleagues to be more vigilant about complete reporting outcomes and not 'waste' data. The comparative effectiveness of glaucoma interventions could be better determined with more complete reporting on VF and other patient-centered outcomes.