Table 1 Comparison of non-truncated RCTs only and truncated + non-truncated RCTs as comparators to estimate the magnitude of bias associated with stopping clinical trials early for benefit based on simulations and theoretical considerations.
Non-truncated RCTs only | Truncated & non-truncated RCTs |
|---|---|
- more appropriate when the number of non-truncated RCTs in meta-analyses is relatively small (= weight of tRCTs in meta-analyses relatively large) | - more appropriate when the number of non-truncated RCTs in meta-analyses is relatively large (= weight of tRCTs in meta-analyses relatively small) |
- more appropriate when true treatment effects are small (RCTs in meta-analyses likely to be underpowered) | - more appropriate when true treatment effects are large (RCTs in meta-analyses likely to be adequately powered) |
- more appropriate in the presence of considerable publication bias | - more conservative bias estimation |
- more appropriate when proportion of trials in meta-analyses without formal stopping rule is large | |
- trial sample separate/independent from tRCT(s) facilitates statistical analysis |