Table 5. Combined effects of residence at birth and parental history of allergic disease as risk factors for asthma among schoolchildren in a case-control study from 2015 to 17 (N = 1,532).
| Child’s residence at birth | Parental history of allergy | Asthma cases N = 526 | Non-asthmatic controls N = 1006 | Adj. OR (95% CI)* |
|---|---|---|---|---|
| Rural | − | 27 (5.1) | 158 (15.7) | 1 |
| Town | − | 137 (26.1) | 383 (38.1) | 2.15 (1.35–3.44) |
| City | − | 20 (3.8) | 31 (3.1) | 3.33 (1.61–6.90) |
| Rural | + | 42 (8.0) | 85 (8.4) | 2.78 (1.58–4.89) |
| Town | + | 253 (48.1) | 306 (30.4) | 5.16 (3.25–8.17) |
| City | + | 47 (8.9) | 43 (4.3) | 5.54 (2.99–10.26) |
Adj. OR = adjusted odds ratio; CI = confidence interval; N = number; ‘−' refers to no history of parental allergy, ‘+' refers to positive history of parental allergy. number (%) in 3rd and 4th column. *Adjusted for child’s age, sex, and father’s education level. Parental history of allergic disease included a history of asthma, eczema, allergic rhinitis, allergic conjunctivitis and any other allergies.