Table 1.
Sample-size calculation
| Expected treatment effect (L/min) |
Expected SD within group (L/min) |
|||||
|---|---|---|---|---|---|---|
| 50 | 100 | 150 | 200 | 250 | 300 | |
| 50 |
15 |
58 |
125 |
250 |
400 |
600 |
| 100 |
5 |
15 |
35 |
60 |
95 |
125 |
| 150 |
<5 |
8 |
15 |
26 |
42 |
58 |
| 200 | <5 | 5 | 10 | 16 | 24 | 34 |
Estimates of required number of participants per study group to give 80% power at the 5% significance level, according to different expected treatment-effect sizes and different expected group standard deviations (SDs) of the primary outcome (peak expiratory cough flow (PECF) of voluntary cough).