Table 3.
Responsiveness of Frailty Measures and Sample Size Considerations for Clinical Trials
| Frailty Measures | Clinically Meaningful Change* | SD of Change in Stable Group | Responsiveness Index | Sample Size (Per Group)† |
|---|---|---|---|---|
| FI (38 items)‡ | ||||
| Small change | 0.030 | 0.055 | 0.552 | 51 |
| Large change | 0.076 | 0.058 | 1.319 | 9 |
| FI (43 items)§ | ||||
| Small change | 0.028 | 0.068 | 0.417 | 90 |
| Large change | 0.067 | 0.058 | 1.154 | 12 |
| Frailty phenotype | ||||
| Small change | 0.097 | 1.172 | 0.083 | 2,294 |
| Large change | 0.607 | 1.210 | 0.502 | 62 |
| FRAIL scale | ||||
| Small change | 0.269 | 1.041 | 0.258 | 236 |
| Large change | 0.368 | 1.074 | 0.343 | 133 |
| SOF index | ||||
| Small change | 0.028 | 0.593 | 0.046 | 7,272 |
| Large change | 0.287 | 0.610 | 0.471 | 71 |
Note: FI = frailty index; FRAIL = Fatigue, Resistance, Ambulation, Illness, and Loss of weight; SOF = Study of Osteoporotic Fracture; SD = standard deviation.
*Clinically meaningful changes were estimated from the anchor-based method.
†Sample size was estimated for a 1:1 two-arm clinical trial to detect small and large clinically meaningful changes, with 5% Type I error and 80% power.
‡The 38-item FI was calculated from 38 self-reported items.
§The 43-item FI was calculated from 38 self-reported items and 5 performance test items.