Abstract
A survey of randomized controlled trials found that almost a quarter of trials had more than 10% of responses missing for the primary outcome. There are a number of ways in which data could be missing: the subject is unable to provide it, or they withdraw, or become lost to follow-up. Such attrition means that balance in baseline characteristics for those randomized may not be maintained in the subsample who has outcome data. For individual trials, if the attrition is systematic and linked to outcome, then this will result in biased estimates of the overall effect. It then follows that if such trials are combined in a meta-analysis, it will result in a biased estimate of the overall effect and be misleading. The aim of this study was to investigate the impact of attrition on baseline imbalance within individual trials and across multiple trials.
Original language | English |
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Pages (from-to) | 1264-1270 |
Number of pages | 7 |
Journal | Journal of Clinical Epidemiology |
Volume | 63 |
Issue number | 11 |
DOIs | |
Publication status | Published - Nov 2010 |
Keywords
- Bias (Epidemiology)
- Data Collection
- Humans
- Meta-Analysis as Topic
- Musculoskeletal Diseases
- Patient Dropouts
- Randomized Controlled Trials as Topic