Table 3.

Impact of change in characteristics on the development of incident disability in Valued Life Activities (VLA).

Incident Disability in Valued Life Activities (VLA)
Characteristic	VLA, Newly Unable to Perform* n = 55/609 (9%)		Mean VLA Rating, Meaningful Increase* n = 91/619 (15%)
	OR (95% CI)**	p-value	OR (95% CI)**	p-value
Baseline FEV1	1.76 (1.21 – 2.56)	<0.01	1.11 (0.84 – 1.45)	0.48
Decrement in FEV1†	1.57 (1.15 – 2.15)	<0.01	1.58 (1.24 – 2.00)	<0.01
Baseline 6MWT	2.65 (1.87 – 3.75)	<0.01	1.46 (1.10 – 1.92)	<0.01
Decrement in 6MWT‡	1.43 (1.10 – 1.85)	<0.01	1.37 (1.11 – 1.69)	<0.01
Baseline quadriceps strength	1.75 (1.18 – 2.58)	<0.01	1.08 (0.80 – 1.46)	0.63
Decrement in quadriceps strength	1.39 (1.00 – 1.95)	0.05	1.09 (0.85 – 1.42)	0.49
Baseline SPPB	1.85 (1.42 – 2.41)	<0.01	1.32 (1.05 – 1.66)	0.02
Decrement in SPPB††	1.43 (1.11 – 1.84)	<0.01	1.14 (0.91 – 1.41)	0.26
Baseline COPD Severity Score	2.19 (1.65 – 2.90)	<0.01	1.37 (1.09 – 1.73)	<0.01
Increase in COPD Severity Score	1.94 (1.45 – 2.59)	<0.01	1.37 (1.09 – 1.72)	<0.01

^†FEV₁ = forced expiratory volume in one second;

^‡6MWT = Six minute walk distance;

^††SPPB = Short Physical Performance Battery

^*Newly unable to perform defined as a new rating of “unable” in any activity domain from T0 to T1; a Meaningful increase defined as a ½ standard deviation increase in the mean difficulty in rated items from T0 to T1

^**Odds ratios expressed per standardized per Z unit (one standard deviation) decrement in FEV₁, 6MWT, Quadriceps Strength or SPPB or increase in COPD Severity Score. FEV_1, 6MWT, COPD Severity Score, quadriceps strength and SPPB were tested in separate multivariable logistic regression models that included the baseline value of the predictor as well as its change over time. All models also include gender, age, body mass index, change in body mass index, race, smoking status, and second-hand smoke exposure.