TABLE 2.
Sample size estimates to achieve 80% power, comparing intermittent and repeated measures
| Outcome | Effect size % | Measurement frequency
|
|
|---|---|---|---|
| Weekly×24 | Weeks 1 and 24 | ||
| FVC; assumed control change of −50 mL | 20 | 5946 | 24002 |
| 35 | 1942 | 7837 | |
| 50 | 951 | 3840 | |
| FVC; assumed control change of −100 mL | 20 | 1487 | 6000 |
| 35 | 485 | 1959 | |
| 50 | 238 | 960 | |
| FVC; assumed control change of −150 mL | 20 | 661 | 2667 |
| 35 | 216 | 871 | |
| 50 | 106 | 427 | |
| UCSD-SOBQ | 20 | 1778 | 1731 |
| 35 | 581 | 565 | |
| 50 | 285 | 277 | |
| Dyspnoea VAS | 20 | 5122 | 4993 |
| 35 | 1672 | 1630 | |
| 50 | 819 | 799 | |
FVC: forced vital capacity; UCSD-SOBQ: University of California, San Diego Shortness of Breath Questionnaire; VAS: visual analogue score.