Table 3 – Simulation results for scenarios where a non-random subset is re-randomised, outcomes differ across randomisation periods, or treatment effects carryover into subsequent randomisation periodsa
|  | Treatment effect = 0 | Treatment effect = 0.4 | ||
|---|---|---|---|---|
| Â | Estimated treatment effect | Type I error rate (%) | Estimated treatment effect | Difference in power vs. parallel group trialb (%) |
Scenario 1: Sicker patients are re-randomised | Â | Â | Â | Â |
 • Unadjusted for patient effects | 0.0 | 5.1 | 0.4 | −0.4 |
 • Adjusted for patient effectsc | 0.0 | 5.2 | 0.4 | +10.8 |
Scenario 2: Patients who experienced a poor outcome are more likely to be re-randomised | Â | Â | Â | Â |
 • Unadjusted for patient effects | 0.0 | 4.4 | 0.4 | −1.2 |
 • Adjusted for patient effectsc | 0.0 | 4.8 | 0.4 | +6.1 |
Scenario 3: Patients who received the intervention are more likely to be re-randomised | Â | Â | Â | Â |
 • Unadjusted for patient effects | 0.0 | 5.0 | 0.4 | −0.3 |
 • Adjusted for patient effectsc | 0.0 | 4.8 | 0.4 | +7.3 |
Scenario 4: Patients who received the control are more likely to be re-randomised | Â | Â | Â | Â |
 • Unadjusted for patient effects | 0.0 | 4.7 | 0.4 | −0.3 |
 • Adjusted for patient effectsc | 0.0 | 5.4 | 0.4 | +7.0 |
Scenario 5: Patients’ health status changes for their subsequent re-randomisationd |  |  |  |  |
 • Unadjusted for patient effects | 0.0 | 5.3 | 0.4 | −1.0 |
 • Adjusted for patient effectsc | 0.0 | 5.1 | 0.4 | +13.9 |
Scenario 6: The intervention effect carries over into subsequent randomisation periods | Â | Â | Â | Â |
 • Unadjusted for patient effects | NA | NA | 0.4 | −2.9 |
 • Adjusted for patient effectsc | NA | NA | 0.3 | −22.9 |
 • Adjusted for patient effectsc, and adjusted for number of previous allocations to the intervention | NA | NA | 0.4 | +13.3 |
Scenario 7: The intervention and control effects carry over differentially into subsequent randomisation periods | Â | Â | Â | Â |
 • Unadjusted for patient effects | NA | NA | 0.4 | −10.3 |
 • Adjusted for patient effectsc | NA | NA | 0.3 | −29.8 |
 • Adjusted for patient effectsc, and adjusted for number of previous allocations to the intervention | NA | NA | 0.5 | +18.4 |
 • Adjusted for patient effectsc, and adjusted for both the number of previous allocations to the intervention and number of previous allocations to the control | NA | NA | 0.4 | +10.0 |