Table 2.

Associations (95% CIs, p-values) between long-term concentrations of pollutants and percent emphysema on CT.

Model	1-year average		20-year average
	PM2.5 (n = 6,515)	NOx (n = 6,515)	PM2.5 (n = 4,813)	PM10 (n = 4,813)
Minimal control (demographics)	0.4 (–0.1, 0.8)	0.3 (0.0, 0.6)	1.0 (0.7, 1.4)	0.4 (0.1, 0.6)
Moderate control (risk factors)	0.6 (0.1, 1.2)	0.5 (0.1, 0.9)	1.0 (0.6, 1.4)	0.4 (0.1, 0.7)
Full control (site adjusted)	–0.6 (–1.5, 0.3)	–0.5 (–1.1, 0.0)	0.2 (–0.3, 0.7)	–0.5 (–1.2, 0.2)
Associations were scaled to 5 μg/m3 for PM and 25 ppb for NOx. Minimal control models were adjusted for age, race/ethnicity, and sex. Moderate control models added height, body mass index, education, household size, birth location, smoking, examination, scanner, and scanner by body size. Full control models incorporated site adjustment using a fixed effect.