Table 2 Association between change in traffic-originated PM10 and asthma incidence among SAPALDIA never-smokers
NHR (95% CI)p Value
Unadjusted association27251.28 (1.01 to 1.61)0.040
Adjusted for:
    Age, gender27251.22 (0.98 to 1.51)0.072
    Age, gender, baseline atopy, BMI, BHR, maternal allergies (main model)23901.30 (1.05 to 1.61)0.018
    Main model + paternal asthma23031.34 (1.08 to 1.67)0.007
    Main model + random effect for study area23901.32 (1.06 to 1.65)0.013
    Main model + education and work exposure23681.30 (1.05 to 1.61)0.018
    Main model + FEV1 at baseline (% predicted)23901.30 (1.05 to 1.61)0.015
    Main model + environmental tobacco smoke at baseline23901.30 (1.05 to 1.61)0.018
    Main model + years lived at SAPALDIA 2 address23801.30 (1.03 to 1.63)0.025
    Main model, non-movers only (same residence SAPALDIA 1 and 2)20221.53 (1.02 to 2.28)0.039
    Main model, but loose definition of “new asthma”*24091.17 (0.96 to 1.42)0.114
  • BHR, bronchial hyperreactivity; BMI, body mass index; CI, confidence interval; FEV1, forced expiratory volume in 1 s; HR, hazard ratio; PM10, particulate matter up to 10 μm in diameter; SAPALDIA, Swiss Cohort Study on Air Pollution and Lung Diseases in Adults.

  • Hazard ratios (HR) are given per 1 μg/m3 dTPM10 and presented for several models. The first two models include all 41 new cases of asthma; the others are based on 38 new cases due to some missing data in the covariates.

  • *Includes newly reported asthma at SAPALDIA 2 but age of onset reported as before SAPALDIA 1; age of onset was set to 0.1 years.