Table 2 Statistical power estimates for differing drop-out rates and ICCs
Drop-out | 15% | 20% | 25% | 30% | |||||
|---|---|---|---|---|---|---|---|---|---|
Assumed ICC | 0.05 | 0.10 | 0.05 | 0.10 | 0.05 | 0.10 | 0.05 | 0.10 | |
770 | 93% | 88% | 91% | 86% | 90% | 85% | 88% | 82% | |
Total | 720 | 91% | 86% | 90% | 85% | 88% | 83% | 83% | 77% |
Randomised | |||||||||
620 | 88% | 83% | 86% | 81% | 84% | 79% | 87% | 76% | |
500 | 82% | 77% | 79% | 75% | 78% | 73% | 82% | 71% | |