Table 2. Factors associated with secondary gastroenteritis among 3,916 household contacts.
| Characteristic | Adjusted odds ratio (95% CI)* | p value* |
|---|---|---|
| Age, y | ||
| <2 | 8.0 (5.5–11.4) | <0.0001 |
| 2–5 | 3.0 (2.0–4.3) | <0.0001 |
| 6–17 | 2.0 (1.5–2.8) | <0.0001 |
| ≥18 | Reference | |
| Shares bed with primary case-patient | 2.0 (1.5-2.7) | <0.0001 |
| Exposure/primary vomiting episode | 1.6 (1.2–2.2) | 0.001 |
| Member of index family | 2.5 (1.7–3.6) | <0.0001 |
| Primary cases, no. | 1.5 (1.0–2.2) | 0.07 |
| Primary cases, ≥5 y | 1.7 (1.3–2.3) | 0.0009 |
| Primary cases, duration, days | 1.09 (1.0–1.1) | <0.0001 |
*p values and confidence intervals (CI) obtained by logistic regression for correlated observations, assuming exchangeable correlation within households.