Table 3.

Adjusted estimates for percent predicted FEV₁ and FVC associated with education level stratified by age category

		FEV1 % Predicteda		FVC % Predicteda
		Estimate (95 % CI)	P-value	Estimate (95 % CI)	P-value
Age < 40	Low	−0.82 (−2.01, 0.37)	0.18	−1.34 (−2.58, −0.10)	0.03
	Intermediate	−0.58 (–1.25, 0.09)	0.09	−0.77 (−1.47, −0.08)	0.03
	High	Reference	.	Reference	.
	Trend test p-value		0.08		0.01
Age 40 – 64	Low	−1.85 (−3.05, −0.66)	<0.01	−2.23 (−3.39, −1.08)	<0.01
	Intermediate	−0.64 (−1.77, 0.49)	0.27	−0.81 (−1.91, 0.28)	0.14
	High	Reference	.	Reference	.
	Trend test p-value		<0.01		<0.01
Age ≥ 65	Low	−4.76 (−7.33, −2.20)	<0.01	−5.50 (−7.60, −3.40)	<0.01
	Intermediate	−1.65 (−4.39, 1.09)	0.24	−1.42 (−3.67, 0.82)	0.21
	High	Reference	.	Reference	.
	Trend test p-value		<0.01		<0.01

^aAdjusted for SHS exposure (yes or no), smoking history (current, former, and never), pack years of smoking, biomass exposure (yes or no), low fruit/vegetable diet (<1/day serving of either fruits or vegetables), mode of transport to work, and occupational category