Asthma exacerbation and proximity of residence to major roads: a population-based matched case-control study among the pediatric Medicaid population in Detroit, Michigan

Table 3 Estimated odds ratios for asthma events using polychotomous conditional logistic regression models.

Model	Covariate	Term	Single claimants versus controls				Multiple claimants versus controls
			OR¹	95% CI²		P-value	OR	95% CI		P-value
1	Primary Road	Primary	0.982	0.933	1.035	0.50	0.967	0.935	0.999	0.04
2	Secondary Road	Secondary	0.979	0.927	1.035	0.46	1.002	0.967	1.037	0.93
3	Primary Road + Secondary Road	Primary	0.980	0.930	1.033	0.45	0.966	0.935	0.999	0.04
		Secondary	0.977	0.924	1.033	0.42	0.998	0.963	1.034	0.91
4	RFRS⁴(Primary Road)	Primary	1.131	0.583	2.194	0.72	1.029	0.665	1.593	0.90
5	RFRS(Secondary Road)	Secondary	1.163	0.678	1.994	0.58	0.922	0.658	1.293	0.64
6	RFRS(Primary Road) + RFRS(Secondary Road)	Primary	1.126	0.580	2.184	0.73	1.031	0.666	1.596	0.89
		Secondary	1.160	0.676	1.990	0.59	0.922	0.658	1.292	0.64

² OR: Odds ratio
³ CI: Confidence interval
⁴ RFRS: Reduced form response surface transformation
Estimated odds ratios for asthma events with a kilometer increase of distance from main roads or with a 1-unit increase of RFRS transformed distance, using polychotomous conditional logistic regression models with two sub-types of cases: single claims and cases with two or more claims in the study period.

ISSN: 1476-069X