Table 2.

Association between Baseline Cardiorespiratory Fitness and Annualized Decline in Lung Health from Peak Measurement to Year 20

	Model 1		Model 2
	β (95% CI)	P Value	β (95% CI)	P Value
Decline* FEV1, ml/yr	−1.00 (−1.230 to −0.70)	<0.001	−0.43 (−0.76 to −0.09)	0.01
Decline* FVC, ml/yr	−1.55 (−1.92 to −1.18)	<0.001	−0.50 (−0.91 to −0.10)	0.01
Decline* FEV1/FVC, %/yr	0.52 (0.00 to 0.91)	0.03	−0.31 (−0.72 to .23)	0.30

Definition of abbreviation: CI = confidence interval.

Values shown are per minute baseline treadmill duration (a negative coefficient indicates that greater baseline fitness is associated with less decline in lung function). Model 1 covariates: age, race-sex group, height, center, peak lung function, years from peak lung function to Year 20. Model 2 covariates: model 1 + body mass index (Yr 0), change in body mass index (Yr 0 to Yr 20), lifetime pack-years smoked (Yr 20).

^*Decline is defined as peak minus Year 20 lung function such that a positive number denotes a greater decline in lung function and a negative number denotes less decline.