Table 6. Combined effects of residence at birth and atopy as asthma risk factors among schoolchildren in a case-control study between 2015–17 (N = 1,635).
| Child’s residence at birth | Atopy (SPT to any of 7 allergens) | Asthma cases N = 546 | Non-asthmatic controls N = 1089 | Adj. OR (95% CI)* |
|---|---|---|---|---|
| Rural | - | 42 (7.7) | 191 (17.5) | 1 |
| Town | - | 177 (32.4) | 504 (46.3) | 1.72 (1.16–2.55) |
| City | - | 25 (4.6) | 43 (4.0) | 2.63 (1.41–4.91) |
| Rural | + | 31 (5.7) | 81 (7.4) | 1.77 (1.02–3.05) |
| Town | + | 228 (41.7) | 236 (21.7) | 4.61 (3.07–6.90) |
| City | + | 43 (7.9) | 34 (3.1) | 4.67 (2.56–8.52) |
Adj. OR = adjusted odds ratio; CI = confidence interval; N = number; SPT = skin prick test; ‘-' refers to SPT negative, ‘+' refers to SPT positive to any of seven crude extracts of Blomia tropicalis, Dermatophagoides mix, cockroach, peanut, cat, weeds pollen mix, and mould mix. number (%) in 3rd and 4th column. *Adjusted for child’s age, sex and father’s education level.