Power and sample size scenarios
| Conservative | Ambitious | |||
| Control group readmission rate* | 13.52% | 13.52% | 13.52% | 13.52% |
| Intervention group readmission rate | 9.60% | 9.10% | 10.20% | 9.70% |
| Power | 80% | 90% | 80% | 90% |
| Detectable difference | 3.9% | 4.4% | 3.3% | 3.8% |
| Projected study sample size | 1117 | 1117 | 1582 | 1582 |
Two-group X2 test of equal proportions (equal n’s), two-sided test, final analysis α=0.048.
*Historical Vanderbilt University Medical Center readmission rates.