Table 2 Association between change in traffic-originated PM₁₀ and asthma incidence among SAPALDIA never-smokers

	N	HR (95% CI)	p Value
Unadjusted association	2725	1.28 (1.01 to 1.61)	0.040
Adjusted for:
Age, gender	2725	1.22 (0.98 to 1.51)	0.072
Age, gender, baseline atopy, BMI, BHR, maternal allergies (main model)	2390	1.30 (1.05 to 1.61)	0.018
Main model + paternal asthma	2303	1.34 (1.08 to 1.67)	0.007
Main model + random effect for study area	2390	1.32 (1.06 to 1.65)	0.013
Main model + education and work exposure	2368	1.30 (1.05 to 1.61)	0.018
Main model + FEV₁ at baseline (% predicted)	2390	1.30 (1.05 to 1.61)	0.015
Main model + environmental tobacco smoke at baseline	2390	1.30 (1.05 to 1.61)	0.018
Main model + years lived at SAPALDIA 2 address	2380	1.30 (1.03 to 1.63)	0.025
Main model, non-movers only (same residence SAPALDIA 1 and 2)	2022	1.53 (1.02 to 2.28)	0.039
Main model, but loose definition of “new asthma”*	2409	1.17 (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.