Table 2.

ORs (95% CIs) of the prevalence of chronic respiratory diseases (CRDs) and its components according to quartiles of composite dietary antioxidant index (CDAI) among adults in NHANES 2001–2018.

	Quartiles of CDAI
	<-2.26	[-2.26 to −0.37]	[-0.38-1.98]	>1.98	Ptrend
CRDs
Crude	1 [Reference]	0.87 (0.79–0.96)	0.80 (0.72–0.88)	0.81 (0.73–0.89)	<0.01
Model 1	1 [Reference]	0.90 (0.82–0.99)	0.82 (0.74–0.90)	0.83 (0.75–0.91)	<0.01
Model 2	1 [Reference]	0.91 (0.82–1.01)	0.82 (0.74–0.91)	0.81 (0.72–0.91)	<0.01
Asthma
Crude	1 [Reference]	0.90 (0.82–1.00)	0.87 (0.79–0.96)	0.90 (0.80–1.02)	0.09
Model 1	1 [Reference]	0.94 (0.85–1.04)	0.90 (0.82–1.00)	0.93 (0.82–1.05)	0.19
Model 2	1 [Reference]	0.92 (0.82–1.02)	0.87 (0.79–0.97)	0.87 (0.76–1.00)	0.05
Emphysema
Crude	1 [Reference]	0.86 (0.68–1.09)	0.59 (0.46–0.75)	0.44 (0.33–0.58)	<0.01
Model 1	1 [Reference]	0.81 (0.63–1.02)	0.56 (0.44–0.71)	0.43 (0.32–0.57)	<0.01
Model 2	1 [Reference]	0.96 (0.74–1.25)	0.72 (0.53–0.97)	0.57 (0.40–0.81)	<0.01
Chronic bronchitis
Crude	1 [Reference]	0.77 (0.67–0.90)	0.63 (0.54–0.73)	0.63 (0.55–0.72)	<0.01
Model 1	1 [Reference]	0.80 (0.68–0.93)	0.64 (0.55–0.75)	0.64 (0.55–0.74)	<0.01
Model 2	1 [Reference]	0.86 (0.73–1.02)	0.73 (0.62–0.86)	0.74 (0.62–0.88)	<0.01

Model 1 was adjusted for age (20–39, 40–59, or ≥60), sex (male or female), and race (Mexican American, Other Hispanic, Non-Hispanic White, Non-Hispanic Black or Other).

Model 2 was adjusted for Model 1 plus education level (below high school, high school, or above high school), family income-to-poverty ratio (≤1.0, 1.1–3.0, or >3.0), smoking status (never smoker, former smoker, or current smoker), drinking status (nondrinker, low-to-moderate drinker, or heavy drinker), BMI (<25.0, 25.0–29.9, or >29.9), energy intake levels (in quartiles), physical activity (inactive, insufficiently active, or active), diabetes (yes or no), hypertension (yes or no), and supplement use (yes or no)