Table 3.
Sample size calculation
| Sample size (per group) | Baseline incidence | ||
|---|---|---|---|
| 10% (wheeze) | 6.2% (preterm birth) | 5% (low birth weight) | |
| Detectable odds ratios: | |||
| 100 | 3.00 | 3.62 | 3.19 |
| 200 | 2.25 | 2.63 | 2.26 |
| 300 | 1.96 | 2.24 | 1.91 |
| 400 | 1.80 | 2.04 | 1.74 |
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