Table 7. Combined effects of father’s education and residence at birth as asthma risk factors among schoolchildren in a case-control study from 2015 to 17 (N = 1,670).
| Father’s education level | Child’s residence at birth | Asthma cases N = 555 |
Non-asthma controls N = 1115 |
Adj. OR (95% CI)* |
|---|---|---|---|---|
| Primary | Rural | 20 (3.6) | 115 (10.3) | 1 |
| Primary | Town | 67 (12.1) | 206 (18.5) | 2.13 (1.22–3.74) |
| Primary | City | 12 (2.2) | 17 (1.5) | 4.98 (2.02–12.31) |
| Secondary | Rural | 26 (4.7) | 109 (9.8) | 1.39 (0.72–2.66) |
| Secondary | Town | 156 (28.1) | 268 (24.0) | 3.97 (2.34–6.76) |
| Secondary | City | 11 (1.9) | 24 (2.2) | 2.80 (1.16–6.76) |
| Tertiary | Rural | 28 (5.0) | 54 (4.8) | 3.22 (1.64–6.33) |
| Tertiary | Town | 189 (34.1) | 283 (25.4) | 4.96 (2.89–8.53) |
| Tertiary | City | 46 (8.3) | 39 (3.5) | 6.95 (3.52–13.71) |
N = number; CI = confidence interval; Adj. OR = adjusted odds ratio; 3rd and 4th column contain n (%); *Adjusted for child’s age and sex. Similar pattern was observed for mother’s education level and child’s residence at birth.