Table 3.

Multivariate regression modeling predicting maximum asthma symptom-days by radon 1-month and 2-month moving average.

	Radon 1-month moving average		Radon 2-month moving average
	IRR	p-value, 95% CI	IRR	p-value, 95% CI
Maximum Asthma Symptom-Daysa	1.014	p=0.0273, 1.002 to 1.027	1.015	p=0.0286, 1.002 to 1.028

Main effects of indoor radon exposure predicting maximum asthma symptom-days in school-age children with asthma show a positive association between radon 1-month moving average (IRR=1.014, 95% CI [1.002,1.027], p=0.0273) and radon 2-month moving average (IRR=1.015, 95% CI [1.002,1.028], p=0.0286) with maximum symptom-days (n=299, obs=1,167). Multivariate model: Maximum symptoms-days adjusted for Age, Race, Gender, BMI, ICS controller medication use, allergic sensitization, and household income <$25,000.

IRR = Incidence rate ratio, CI = Confidence interval

^aMaximum asthma symptom-days = in the 2 weeks prior to each follow-up survey, the greatest result of the following three variables: 1) number of days with wheezing, cough, or chest tightness, 2) number of days on which child had to slow down or discontinue play activities due to wheezing, chest tightness, or cough, 3) number of nights with wheezing, cough, or chest tightness leading to disturbed sleep due to child’s asthma