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Table 2 Adjusted HR (95% CI) for asthma medication and diagnoses, in relation to traffic-related exposure, n = 7898

From: Asthma incidence in children growing up close to traffic: a registry-based birth cohort

  Inhaled asthma medicationa Diagnosesa
β2-agonist β2-agonist Corticosteroid Corticosteroid Bronchiolitis Obstructive bronchitis Asthma
  1st purchase 3rd year 1st purchase 3rd year
Heaviest road ≤100 m, birth address b
0–8640 cars/day 1.0 1.0 1.0 1.0 1.0 1.0 1.0
≥8640 cars/day 0.9 (0.8–1.0) 0.7 (0.6– 0.9) 0.8 (0.7–0.9) 0.8 (0.6–1.0) 0.7 (0.6–0.9) 1.0 (0.9–1.2) 0.7 (0.6–0.9)
Heaviest road ≤100 m, never moved b
0–8640 cars/day 1.0 1.0 1.0 1.0 1.0 1.0 1.0
≥8640 cars/day 0.9 (0.7–1.0) 0.7 (0.5–1.0) 0.8 (0.6–0.9) 0.9 (0.6–1.2) 0.7 (0.6–0.9) 1.0 (0.8–1.2) 0.7 (0.6–0.9)
NO X, birth address c
≤15 μg/m3 1.0 1.0 1.0 1.0 1.0 1.0 1.0
15–25 0.8 (0.7–1.0) 0.7 (0.5–0.8) 0.8 (0.7–0.9) 0.7 (0.5–0.9) 0.6 (0.5–0.8) 1.1 (0.9–1.3) 0.8 (0.7–0.9)
>25 0.7 (0.6–0.9) 0.6 (0.4–0.8) 0.7 (0.5–0.9) 0.6 (0.4–0.8) 0.5 (0.4–0.8) 1.1 (0.8–1.4) 0.7 (0.5–0.9)
NO X , never moved c
≤15 μg/m3 1.0 1.0 1.0 1.0 1.0 1.0 1.0
15–25 0.8 (0.7–1.0) 0.6 (0.4–0.8) 0.8 (0.7–0.9) 0.6 (0.4–0.8) 0.6 (0.5–0.8) 1.1 (0.9–1.3) 0.8 (0.7–0.9)
>25 0.8 (0.6–1.0) 0.5 (0.3–0.9) 0.6 (0.5–0.8) 0.5 (0.3–0.9) 0.5 (0.4–0.8) 1.1 (0.8–1.5) 0.7 (0.5–0.9)
NO X, lifetime mean d
≤15 μg/m3 1.0 1.0 1.0 1.0 1.0 1.0 1.0
15–25 0.8 (0.7–0.9) 0.7 (0.6–0.9) 0.7 (0.6–0.9) 0.7 (0.6–0.9) 0.7 (0.5–0.8) 0.9 (0.8–1.1) 0.7 (0.6–0.9)
>25 0.8 (0.6–1.1) 0.5 (0.3–0.9) 0.6 (0.5–0.9) 0.5 (0.3–0.9) 0.7 (0.5–1.0) 1.0 (0.7–1.3) 0.7 (0.5–1.0)
  1. aadjusted for sex, ETS, breastfeeding, parental allergy, parental origin, parental education, and year of birth.
  2. bn = 6007 children had complete covariate information and traffic exposure assessments.
  3. cn = 6005 children had complete covariate information and modeled NOX concentrations.
  4. dnumber of children with complete covariate information and modeled mean NOX during time at risk varies between n = 5194-5248 depending on outcome.