TABLE 3.
Likelihood of Having Asthma at Ages 6 Years (n = 2151) and 14 Years (n = 1796), by Income Trajectory: Western Australia Pregnancy Cohort (Raine) Study, Perth, Australia, 1989–2005
| Asthma at Age 6 Years, OR (95% CI) | Asthma at Age 14 Years, OR (95% CI) | |
| Unadjusted model | ||
| Chronic low income | 1.30 (0.94, 1.81) | 1.67 (0.97, 2.86) |
| Increasing income | … | 0.79 (0.40, 1.55) |
| Decreasing income | … | 1.26 (0.87, 1.83) |
| Model adjusted for asthma risk factorsa | ||
| Chronic low income | 1.30 (0.92, 1.83) | 2.30 (1.23, 4.31) |
| Increasing income | … | 0.89 (0.43, 1.87) |
| Decreasing income | … | 1.31 (0.89, 1.93) |
| Single parent family at age 1 y | not in model | 0.49 (0.26, 0.94) |
| Model adjusted for asthma risk factorsa and stress at age 1 y | ||
| Chronic low income | 1.14 (0.74, 1.75) | 2.34 (1.22, 4.48) |
| Increasing income | … | 0.92 (0.44, 1.92) |
| Decreasing income | … | 1.29 (0.86, 1.94) |
| Single parent family at age 1 y | not in model | 0.40 (0.20, 0.80) |
| Pregnancy stress | 1.69 (1.15, 2.48) | 0.99 (0.54, 1.80) |
| Family stress at age 1 y | 1.42 (1.06, 1.90) | 1.25 (0.81, 1.91) |
| Model adjusted for asthma risk factorsa and chronic family stress | ||
| Chronic low income | 1.17 (0.82, 1.65) | 2.21 (1.17, 4.17) |
| Increasing income | … | 0.83 (0.39, 1.74) |
| Decreasing income | … | 1.25 (0.84, 1.85) |
| Single parent family at age 1 y | not in model | 0.45 (0.24, 0.87) |
| Pregnancy stress | 1.48 (1.05, 2.08) | 1.04 (0.59, 1.82) |
| Chronic family stress | 1.82 (1.16, 2.85) | 2.25 (1.28, 3.97) |
Note. OR = odds ratio; CI = confidence interval. Ellipses indicate not applicable. Reference category is never low income.
a
Asthma risk factors at age 6 years: gender, preterm birth, maternal asthma, and dog ownership in first year. Asthma risk factors at age 14 years: gender, maternal history of asthma, and cat ownership in first year.