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Consistency of outcome and statistical reporting of time-to-event data: The impact on Cochrane Reviews and meta-analyses in epilepsy

Date and Location




Monday 23 September 2013 - 10:30 - 12:00


Presenting author and contact person

Presenting author

Sarah Nolan

Contact person

Sarah Nolan
Abstract text
Background: Inadequate reporting of time-to-event (censored) outcomes and statistical analyses in individual randomised controlled trials is well documented. Therefore, meta-analyses of such outcomes frequently require the re-analysis of individual participant data (IPD). This approach has been undertaken in seven Cochrane reviews in epilepsy, with 60-100% of IPD made available by original trial authors for meta-analysis. When an IPD approach is not feasible or practical or if a proportion of IPD is unavailable for inclusion in meta-analysis as in the epilepsy reviews, methods of meta-analysing study level aggregate data, including indirect estimation methods, are required. The feasibility of indirect estimation methods also depend on the extent and quality of statistical reporting in individual trials. Objectives: We aim to investigate the consistency and quality of reporting of outcomes and statistical analyses of time-to-event data in the context of published epilepsy monotherapy designed studies in order to determine if we can make use of any published summary statistics via indirect estimation or otherwise and therefore avoid biases related to unavailability of IPD Methods: A systematic search of the Cochrane Epilepsy Group Specialised Register has been conducted to identify all epilepsy monotherapy designed studies which report at least one time-to-event outcome. Quality and consistency of reporting will be assessed according to ILAE recommendations for the reporting of outcomes in monotherapy studies and according to statistical recommendations for the reporting of survival analyses. Results and Conclusions (to date): 111 epilepsy monotherapy studies have been identified and the systematic review is underway. Updated results and conclusions will be presented at a later date.