TABLE 5.

Impact of pulmonary function impairment on self-reported functional limitation, California, 2005-2007^*

Functional limitation measure	β-coefficient per 1-liter decrease in FEV1 (SE†)	p value	β-coefficient per 1-liter decrease in FEV12 (quadratic term) (SE)	p value
Self-reported  functional  limitation‡	-1.40 (0.30)	<0.0001	0.17 (0.075)	0.020
Limitation in  moderate  activities§	-1.28 (0.32)	<0.0001	0.15 (0.08)	0.056
Limitation in  climbing  several  flights of  stairs	-1.87 (0.31)	<0.0001	0.23 (0.071)	0.001

^*Multiple variable logistic regression analysis controlling for age, sex, race, height, smoking, and education. The model includes a quadratic term for 1-liter decrease in forced expiratory volume in 1 second (FEV₁) to account for the curvilinear relation between FEV₁ and the log odds of functional limitation (refer to figure 3).

^†SE, standard error.

^‡“Unable to do” or “severe limitation” in a battery of basic physical activities (refer to Materials and Methods).

^§Health limits “a lot” in performing moderate activities, such as moving a table, pushing a vacuum cleaner, bowling, or playing golf.