Sample size calculations comparing total hip arthroplasty (THA) and hemiarthroplasty (HA)
| HA 1 year event risk | Total patients required | Expected events (n) | RRR |
|---|---|---|---|
| 4% | 1123 | 72 | 0.50 |
| 5% | 1316 | 96 | 0.45 |
| 6% | 1435 | 108 | 0.42 |
Sample size requirement for HEALTH Pivotal Trial (non-inferiority design).
RRR, relative risk reduction.