Particulate matter components and subclinical atherosclerosis: common approaches to estimating exposure in a Multi-Ethnic Study of Atherosclerosis cross-sectional study

Table 5 **CAC* relative risk (RR) for pollutant IQR increases by analysis model and exposure estimation approach**

	PM_2.5*	EC*	OC*	Silicon	Sulfur
	RR (95% CI)	RR (95% CI)	RR (95% CI)	RR (95% CI)	RR (95% CI)
Model 1**
Nearest Monitor	1.00 (0.99,1.01)	0.96 (0.93,0.99)	1.03 (0.96,1.09)	0.84 (0.33,2.14)	0.98 (0.91,1.07)
IDW	0.99 (0.98,1.01)	0.95 (0.91,0.99)	0.98 (0.90,1.06)	0.49 (0.16,1.53)	0.98 (0.90,1.06)
City-Wide Average	0.99 (0.98,1.00)	0.94 (0.90,0.98)	1.01 (0.09,1.55)	0.37 (0.09,1.55)	0.97 (0.89,1.05)
Model 2**
Nearest Monitor	1.00 (0.99,1.01)	0.97 (0.94,1.00)	1.01 (0.95,1.07)	0.92 (0.37,2.32)	0.98 (0.90,1.06)
IDW	1.00 (0.98,1.01)	0.96 (0.92,1.00)	0.96 (0.89,1.04)	0.64 (0.21,1.96)	0.97 (0.90,1.05)
City-Wide Average	0.99 (0.98,1.01)	0.95 (0.91,0.99)	0.99 (0.91,1.08)	0.51 (0.12,2.09)	0.97 (0.89,1.05)
Model 3**
Nearest Monitor	1.00 (0.99,1.01)	0.97 (0.94,1.01)	1.03 (0.97,1.09)	1.02 (0.39,2.64)	0.99 (0.91,1.07)
IDW	1.00 (0.99,1.01)	0.96 (0.92,1.00)	0.99 (0.91,1.07)	0.70 (0.22,2.22)	0.98 (0.90,1.06)
City-Wide Average	1.00 (0.98,1.01)	0.96 (0.91,0.99)	1.01 (0.93,1.10)	0.57 (0.13,2.44)	0.97 (0.90,1.06)
Model 4**
Nearest Monitor	1.01 (0.98,1.05)	1.04 (0.94,1.15)	1.08 (0.91,1.28)	***	1.35 (0.79,2.30)
IDW	1.02 (0.97,1.09)	1.11 (0.91,1.34)	***	***	2.04 (0.62,6.66)

*PM_2.5, particulate matter less than or equal to 2.5 μm in aerodynamic diameter; EC, elemental carbon; OC, organic carbon; CAC, coronary artery calcification.
**Model 1: covariates include age, gender, race-ethnicity.
Model 2: Model 1 + total cholesterol, HDL cholesterol, smoking status, hypertension, lipid-lowering medication.
Model 3: Model 2 + education, income, waist circumference, body surface area, BMI, BMI², diabetes, LDL, triglycerides.
Model 4: Model 2 + metropolitan area.
***unstable estimate.

ISSN: 1476-069X