Table 1 Estimated effect size for respiratory outcome (wheeze at any time during first year of life) for anticipated questionnaire returns
Size per group | Prevalence of wheezing after treatment | Detectable effect size |
|---|---|---|
Power 0.8, alpha 0.05, initial incidence of wheeze 65% | ||
350 | 54.3% | 10.7% |
300 | 53.5% | 11.5% |
250 | 52.3% | 12.7% |
200 | 50.7% | 14.3% |
Power 0.9, alpha 0.05, initial incidence of wheeze 65% | ||
350 | 52.7% | 12.3% |
300 | 51.7% | 13.3% |
250 | 50.4% | 14.6% |
200 | 48.5% | 16.5% |