Association of recent wheeze, asthma diagnosis, and medication use with sociodemographic and exposure characteristics (logistic regression model)
| Recent wheeze(N = 13 002) | Asthma diagnosis(N = 13 002) | Asthma medication use(N = 2219) | ||||
|---|---|---|---|---|---|---|
| OR | 95% CI | OR | 95% CI | OR | 95% CI | |
| N, number of observations; records with missing values excluded from analysis. | ||||||
| *p<0.05 (Wald test) for overall significance of variable in the model. | ||||||
| **p <0.05 (t test) for stratum difference from reference stratum. | ||||||
| †Current daily and occasional manufactured and hand rolled cigarettes. | ||||||
| ‡Current daily and occasional pipes, cigars, cheroots, cigarillos. | ||||||
| Women | 1.6* | 1.3 to 1.8** | 1.2 | 0.9 to 1.6 | 0.6* | 0.4 to 0.9** |
| Age (years) | ||||||
| 15–24 | 1.0 | 1.0 | 1.0 | |||
| 25–44 | 0.9 | 0.7 to 1.1 | 0.7 | 0.5 to 1.0 | 1.2 | 0.5 to 2.7 |
| >44 | 1.3* | 1.0 to 1.6 | 1.0* | 0.7 to 1.5 | 2.3* | 1.0 to 5.7 |
| Asset index | ||||||
| I (poorest) | 1.0 | 1.0 | 1.0 | |||
| II | 1.1 | 0.9 to 1.3 | 0.9 | 0.6 to 1.3 | 2.0 | 1.0 to 4.1 |
| III | 0.8 | 0.6 to 1.0** | 0.7 | 0.5 to 1.2 | 1.7 | 0.8 to 3.8 |
| IV | 1.0 | 0.7 to 1.3 | 0.9 | 0.5 to 1.5 | 2.7 | 1.1 to 6.5** |
| V | 0.9 | 0.7 to 1.3 | 0.9 | 0.5 to 1.6 | 2.3 | 0.8 to 6.4 |
| Education (years) | ||||||
| None | 1.0 | 1.0 | 1.0 | |||
| 1–7 | 0.8 | 0.6 to 0.9** | 1.0 | 0.7 to 1.4 | 1.4 | 0.8 to 2.6 |
| 8–12 | 0.5 | 0.4 to 0.7** | 0.5 | 0.3 to 0.8** | 0.8 | 0.4 to 1.6 |
| >12 | 0.4* | 0.3 to 0.6** | 0.6* | 0.4 to 1.1 | 0.6 | 0.2 to 1.8 |
| Racial group | ||||||
| African | 1.0 | 1.0 | 1.0 | |||
| Coloured | 0.8 | 0.6 to 1.0** | 1.3 | 0.9 to 1.9 | 3.3 | 1.9 to 5.7** |
| White | 1.7 | 1.2 to 2.6** | 2.1 | 1.2 to 3.7** | 1.4 | 0.5 to 3.9 |
| Asian | 1.4* | 1.0 to 1.9 | 1.7 | 0.9 to 3.0 | 2.5* | 1.0 to 6.3** |
| Rural residence | 1.1 | 0.8 to 1.6 | 0.9 | 0.6 to 1.4 | 1.4 | 0.7 to 2.7 |
| No medical insurance | 1.0 | 0.8 to 1.2 | 0.7* | 0.5 to 1.0** | 0.6 | 0.3 to 1.2 |
| Smoky domestic fuel | 0.9 | 0.8 to 1.2 | 0.8 | 0.5 to 1.1 | 0.5* | 0.3 to 0.8** |
| Occupational exposure | 1.8* | 1.5 to 2.0** | 1.9* | 1.4 to 2.4** | 1.5 | 1.0 to 2.2 |
| Smoking | ||||||
| Non-smoker | 1.0 | 1.0 | 1.0 | |||
| Light (1–14)† | 1.5 | 1.3 to 1.9** | 1.2 | 0.9 to 1.7 | 0.5 | 0.3 to 0.8** |
| Heavy (15+)† | 1.8 | 1.4 to 2.4** | 1.5 | 0.9 to 2.4 | 0.8 | 0.4 to 1.8 |
| Ex-smokers | 1.3 | 1.1 to 1.6** | 1.2 | 0.9 to 1.8 | 0.8 | 0.4 to 1.3 |
| Non-cigarette‡ | 1.6* | 1.0 to 2.5** | 0.8 | 0.4 to 1.7 | 0.4 | 0.1 to 1.3 |
| Tuberculosis (ever) | 3.4* | 2.5 to 4.7** | 2.2* | 1.5 to 3.2** | 1.0 | 0.5 to 2.0 |
| Body mass index | ||||||
| Normal | 1.0 | 1.0 | 1.0 | |||
| Obese | 1.2 | 1.0 to 1.4** | 1.0 | 0.8 to 1.3 | 1.1 | 0.7 to 1.9 |
| Overweight | 1.0 | 0.9 to 1.2 | 1.0 | 0.7 to 1.3 | 1.2 | 0.7 to 1.9 |
| Underweight | 1.1 | 0.9 to 1.4 | 1.0 | 0.7 to 1.4 | 1.5 | 0.8 to 2.7 |