Figure 2. Comparison of the results of 8000 randomized, controlled trials (RCTs) and 8000 concurrently controlled trials (CCTs) obtained from resampling within the European Carotid Surgery Trial. The distribution of results revealed that 9% of studies within each design had statistically significant findings. Adapted with permission from reference 27: Deeks JJ, Dinnes J, D'Amico R, Sowden AJ, Sakarovitch C, Song F, et al. Evaluating non-randomised intervention studies. Health Technol Assess. 2003;7:iii-x, 1-173.