TABLE 2.

MULTIVARIATE EFFECTS OF BASELINE VARIABLES, BODY MASS INDEX, AND SMOKING STATUS ON CHANGE IN FEV₁, FVC, AND FEV₁/FVC

	ΔFEV1		ΔFVC		Δ(FEV1/FVC)
Covariate	β*	95% Confidence Limits	β*	95% Confidence Limits	β*	95% Confidence Limits
Change in age	−26.3	−44.3, −8.3	−35.2	−58.4, −12.1
Age	11.1	−1.1, 23.3	21.0	4.5, 37.6
Age2	−0.1	−0.2, −0.02	−0.2	−0.4, −0.1
Stature, cm	−2.8	−5.6, 0.1	−4.8	−8.7, −0.8
Change in BMI, kg/m2	−23.8	−36.2, −11.4	−11.4	−27.5, 4.8	−0.5	−0.7, −0.3
Smoking status†
Current (obs = 93)	−68.6	−133.3, −4.0	−45.0	−133.1, 43.1	−1.0	−2.2, 0.2
Started (obs = 7)	−94.4	−314.1, 125.4	−7.1	−293.5, 279.3	−2.5	−6.6, 1.6
Stopped (obs = 15)	−59.0	−213.5, 95.5	−31.7	−234.2, 170.9	−1.4	−4.2, 1.4
Ex (obs = 151)	−22.3	−80.3, 35.6	−32.8	−111.7, 46.1	0.1	−1.0, 1.1

Definition of abbreviations: β = regression coefficient; BMI = body mass index; ΔFEV₁= change in FEV₁ in ml (between two tests); Δ(FEV₁/FVC) = Δ(FEV₁/FVC) × 100 (between two tests); ΔFVC = change in FVC in ml (between two tests).

^*Change over an average of 3.2 years.

^†Reference is never-smokers (137 test intervals).