A proximity model of exposure was previously developed and applied to the CCAAPS cohort (Ryan et al.
CCAAPS is an ongoing prospective birth cohort study.
The model is applied to the identical subset of the CCAAPS cohort previously analyzed using a proximity model (Ryan et al.
A complete description of the air sampling at monitoring stations and the land-use regression (LUR) methodology developed and used to estimate traffic exposure for CCAAPS children has previously been described (Ryan et al.
Potential model covariates were identified based on previous work within the CCAAPS cohort linking environmental exposures with outcomes, and on established risk factors for childhood behavioral disorders, including sex, race/ethnicity, maternal and paternal education, household income, Medicaid status, duration of breastfeeding, pre- and postnatal ETS exposure, hair cotinine, age of home, and child care attendance (Biederman and Faraone 2005; Braun et al.