Table 2.

Associations between outdoor MVA time (minutes) and location-specific annual average concentrations of air pollution

	Main Effect (Nsubjects:nvisits = 151:263)
Air pollutants	Adjusted β-Coefficient (95% CI)*
PM2.5, μg/m3	0.00 (−0.04 to 0.04)
NO2, ppb	0.031 (0.11 to 0.51)†

Definition of abbreviations: CI = confidence interval; MVA = moderate to vigorous activity; NO₂ = nitrogen dioxide; N_subjects = number of subjects included for the analysis; n_visits = total number of visits; PM_2.5 = particulate matter <2.5 microns.

β-coefficients are presented for an interquartile range increase in MVA time, equivalent to 44 minutes. Bold typeface values represent P < 0.05.

^*Models adjusted for asthma, daily average temperature, daily average relative humidity, temporal daily levels of PM_2.5 (or NO₂) at fixed monitoring site, and warmer versus colder months.

^†P < 0.01.