Effects of respiratory and non-respiratory factors on disability among older adults with airway obstruction: The Cardiovascular Health Study

Figures & data

Figure 1. Disablement process in obstructive lung disease [adapted from Jette et al. 1997(6)].

Table 1.   Baseline characteristics of Cardiovascular Health Study participants by spirometry results

	Normal Spirometry N = 3,346		Restriction N = 472		Obstruction N = 1,048		p-value
	n	(%)	n	(%)	n	(%)
Age years, mean (SD)	72.7	(5.5)	71.7	(4.9)	72.7	(5.4)	0.005
Male	1300	(38.9)	225	(47.7)	525	(50.1)	<0.001
Race							0.179
White	2935	(88.1)	421	(90.7)	913	(87.5)
African American	395	(11.9)	43	(9.3)	131	(12.6)
Education							0.001
≤8th grade	427	(12.9)	62	(13.2)	176	(16.9)
9-11th grade	423	(12.2)	67	(14.2)	162	(15.5)
12th grade	941	(28.2)	121	(25.7)	282	(27.0)
>12th grade	1548	(46.7)	221	(46.9)	424	(40.6)
Married	2269	(67.9)	333	(70.6)	689	(65.8)	0.174
Smoking status							<0.001
Never	1768	(52.8)	185	(43.3)	239	(22.9)
Past	1341	(40.4)	208	(41.5)	557	(53.3)
Current	235	(6.8)	81	(15.2)	250	(23.9)
Body mass index (kg/m^2)							<0.001
<25.0	1250	(37.4)	147	(31.6)	490	(46.8)
25.0–29.9	1467	(43.9)	196	(42.1)	393	(37.5)
≥30.0	622	(18.6)	123	(26.4)	165	(15.7)
Dyspnea Scale							<0.001
0	2247	(67.7)	249	(53.1)	505	(48.8)
1	640	(19.3)	95	(20.3)	260	(25.1)
2	136	(4.1)	31	(6.6)	81	(7.8)
3	90	(2.7)	22	(4.7)	60	(5.8)
4	131	(4.0)	50	(10.7)	81	(7.8)
5	76	(2.3)	22	(4.7)	48	(4.6)
Asthma	124	(3.7)	37	(5.6)	144	(13.8)	<0.001
Congestive Heart Failure	116	(3.5)	39	(8.3)	55	(5.3)	<0.001
Ischemic Heart Disease	584	(17.5)	116	(24.8)	224	(21.5)	<0.001
Diabetes	488	(14.6)	116	(24.6)	158	(15.1)	<0.001
Depression	402	(12.0)	77	(16.3)	138	(13.2)	0.027
Osteoporosisa	220	(7.3)	32	(8.1)	72	(6.7)	0.825
Other Chronic Conditionsb							<0.001
0	1726	(51.6)	219	(46.4)	535	(51.1)
1	1453	(43.4)	220	(46.6)	463	(44.2)
≥2	167	(5.0)	33	(7.0)	50	(4.8)
Hand grip strength (kg)^a							0.008
<20	591	(18.9)	88	(20.6)	151	(15.3)
20–39	2024	(64.7)	261	(61.0)	635	(64.5)
≥40	513	(16.4)	79	(18.5)	199	(20.2)
Cognitive Impairment^a	248	(7.8)	44	(10.2)	100	(10.2)	0.024
FEV1, mean (SD)	2.27	(0.59)	1.73	(0.49)	1.57	(0.59)	<0.001
FVC, mean (SD)	3.08	(0.82)	2.33	(0.68)	2.81	(0.89)	<0.001
Table 1. Continued.
	Normal SpirometryN = 3,346		RestrictionN = 472		ObstructionN = 1,048		p-value
	n	(%)	n	(%)	n	(%)
FEV1/FVC ratio, mean (SD)	0.74	(0.0.5)	0.75	(0.08)	0.55	(0.09)	<0.001
FEV1% Predicted, mean (SD)	97.9	(14.52)	68.2	(9.52)	64.69	(20.42)	<0.001
FVC% Predicted, mean (SD)	98.7	(13.44)	68.1	(8.96)	85.60	(21.78)	<0.001
Severity of obstruction
Borderline (> LLN)					384	(36.6)
Mild-Moderate (LLN-50%)					390	(37.2)
Severe (<50%)					274	(26.2)

Note: Percents may not sum to 100 due to rounding.

a. >5% missing information.

b. Other chronic conditions include kidney disease, liver disease, arthritis, cancer, stroke/TIA and claudication.

Table 2.   Respiratory impairment and disability-free years

	Base Model^a		Base + Non-respiratory Impairments & functional limitation^b		Base + Non-respiratory Impairments & functional limitation^b excluding asthma diagnosis
	Coef	(95% CI)	Coef	(95% CI)	Coef	(95% CI)
Spirometry categories
Normal
Restriction	–0.78	(–0.98, –0.59)	–0.51	(–0.70, –0.32)	–0.50	(–0.69, –0.31)
Obstruction
Borderline	0.01	(–0.20, 0.22)	0.01	(–0.19, 0.21)	–0.01	(–0.21, 0.20)
Mild-Moderate	–0.54	(–0.75, –0.33)	–0.36	(–0.56, –0.16)	–0.32	(–0.54, –0.10)
Severe	–1.27	(–1.51, –1.02)	–1.11	(–1.34, –0.87)	–1.00	(–1.26, –0.74)

a. Base Model included the following demographic and social characteristics: age, gender, race, marital status, smoking status, and BMI.

b. Impairments and functional limitations associated with obstructive lung disease: congestive heart failure, ischemic heart disease, diabetes, depression, osteoporosis, cognitive impairment and a count of other chronic conditions including kidney disease, liver disease, arthritis, cancer, stroke/TIA and claudication.

Figure 2. Predicted life expectancy and disability-free life expectancy (of a possible 6 years) by baseline age and lung function. Note: Predicted values are lowess smoothed. In this figure, we excluded participants with baseline age > 85, because of small numbers in the upper age categories (<3% of total participants).

Table 3.  Respiratory and non-respiratory impairments, functional limitations and disability-free years in individuals with baseline airflow obstruction

		Base Modela	Base + Non-respiratory impairmentsb		Base + Non-respiratory impairmentsb + Functional Limitationsc		Base + Non-respiratory Impairmentsb & functional limitationc, excluding diagnosis of asthma
		Coef (95% CI)	Coef	(95% CI)	Coef	(95% CI)	Coef	(95% CI)
Respiratory Impairments	Obstruction
	Borderline	Ref.	Ref.		Ref.		Ref.
	Mild-Moderate	–0.57 (–0.87, –0.27)	–0.47	(–0.77, –0.18)	–0.23	(–0.51, 0.06)	–0.20	(–0.50, 0.10)
	Severe	–1.26 (–1.59, –0.93)	–1.19	(–1.51, –0.87)	–0.69	(–1.01, –0.37)	–0.66	(–1.00, –0.32)
Non-Respiratory Impairments	Heart failure		–0.21	(–0.83, 0.41)	0.05	(–0.54, 0.64)	0.09	(–0.59, 0.77)
	Heart disease		–0.75	(–1.07, –0.43)	–0.55	(–0.85, –0.24)	–0.53	(–0.86, –0.20)
	Diabetes		–0.62	(–0.97, –0.27)	–0.55	(–0.88, –0.21)	–0.51	(–0.88, –0.15)
	Depression		–0.63	(–1.02, –0.25)	–0.38	(–0.75, –0.01)	–0.25	(–0.66, 0.16)
	Osteoporosis		–0.84	(–1.34, –0.34)	–0.82	(–1.29, –0.35)	–0.61	(–1.15, –0.08)
	Co-morbidity Count
	0		Ref.		Ref.		Ref.
	1		–0.54	(–0.79, –0.28)	–0.39	(–0.63, –0.15)	–0.45	(–0.71, –0.19)
	≥2		–1.16	(–1.75, –0.56)	–0.85	(–1.42, –0.29)	–0.88	(–1.53, –0.22)
	Grip strength, per 10 unit decrease		–0.38	(–0.54, –0.21)	–0.33	(–0.49, –0.17)	–0.34	(–0.51, –0.16)
Functional Limitations	Dyspnea Scale
	0				Ref.		Ref.
	1				–0.26	(–0.55, 0.03)	–0.28	(–0.59, 0.03)
	2				–1.11	(–1.56, –0.67)	–0.92	(–1.41, –0.42)
	3				–1.24	(–1.79, –0.69)	–1.01	(–1.63, –0.40)
	4				–2.01	(–2.48, –1.53)	–1.62	(–2.16, –1.08)
	5				–2.46	(–3.12, –1.81)	–2.71	(–3.53, –1.89)
	Cognitive dysfunction				–0.47	(–0.87, –0.07)	–0.53	(–0.97, –0.08)

a. Base Model included the following demographic and social characteristics: age, gender, race, marital status, smoking status, and BMI.

b. Non-respiratory impairments included: congestive heart failure, ischemic heart disease, diabetes, depression, osteoporosis, grip strength and a count of other chronic conditions including kidney disease, liver disease, arthritis, cancer, stroke/TIA and claudication.

c. Functional limitations include dyspnea and cognitive dysfunction.