Table 2.

Association Between Poorer Health Literacy and COPD-Related Health Status Measures Among 277 COPD Subjects

COPD-related health status measure*	Mean ± SD	Difference associated with health literacy tertile (95 % CI)†	Analysis for trend across health literacy tertiles‡
COPD severity score	8.0 ± 6.6	Highest: 0 [referent]	p = 0.025
		Middle: 1.2 (−0.5–3.0)
		Lowest: 2.3 (0.3–4.4)
COPD helplessness index	17.3 ± 6.6	Highest: 0 [referent]	p < 0.001
		Middle: 1.9 (0.1–3.7)
		Lowest: 3.7 (1.6–5.8)
Respiratory-specific HRQoL (AQ-20R)	7.4 ± 5.2	Highest: 0 [referent]	p < 0.001
		Middle: 1.4 (0.1–2.7)
		Lowest: 3.4 (1.8–4.9)

*Each COPD-related health status measure was used as the dependent (outcome) variable in a separate multivariable linear regression in which health literacy was the independent (predictor) variable of interest, and covariates were: age, gender, race, marital status, educational attainment, and income

^†Results indicate that poorer health literacy is associated with poorer health status in each of the three COPD-related measures examined

^‡Test for trend using the linear contrast method indicated a trend of poorer COPD-related health status with decreasing health literacy across tertiles