Table 3.
Subject Characteristics
| Total (n=591) | COPD, emphysema (n=243) | Chronic bronchitis (n=209) | Asthma (n=139) | ||
|---|---|---|---|---|---|
| Sociodemographic factors | |||||
| Age category, % (n) | .01 | ||||
| •55–60 | 19.1 (113) | 15.6 (38) | 23.0 (48) | 19.4 (27) | |
| •61–65 | 28.8 (170) | 23.5 (57) | 32.1 (67) | 33.1 (46) | |
| •66–80 | 52.1 (308) | 60.9 (148) | 45.0 (94) | 47.5 (66) | |
| Female, % (n) | 61.4 (366) | 57.6 (140) | 65.6 (137) | 64.0 (89) | .19 |
| Married/partner, % (n) | 60.9 (354) | 53.5 (130) | 61.5 (128) | 69.1 (98) | .01 |
| Ethnicity (white, non- Hispanic), % (n) | 89.7 (514) | 91.1 (216) | 90.7 (185) | 85.6 (113) | .21 |
| Less than high school education, % (n) | 8.8 (52) | 11.9 (29) | 6.7 (14) | 6.5 (9) | .08 |
| Health status factors | |||||
| Current smoker, % (n) | 18.1 (107) | ||||
| Former smoker, % (n) | 52.8 (312) | 27.6 (67) | 14.4 (30) | 7.2 (10) | <.0001 |
| 62.1 (151) | 47.4 (99) | 44.6 (62) | |||
| Body mass index | .32 | ||||
| Underweight | 2.5 (15) | 3.7 (9) | 1.4 (3) | 2.2 (3) | |
| Normal weight | 27.8 (164) | 31.3 (76) | 23.0 (48) | 28.8 (40) | |
| Overweight | 35.2 (208) | 32.1 (78) | 40.2 (84) | 33.1 (46) | |
| Obese | 34.5 (204) | 32.9 (80) | 35.4 (74) | 36.0 (50) | |
| Comorbidities, % (n) | .20 | ||||
| 0 | 20.8 (123) | 16.9 (41) | 23.0 (48) | 24.5 (34) | |
| 1 | 32.2 (190) | 30.9 (75) | 32.5 (68) | 33.8 (47) | |
| 2 or more | 47.0 (278) | 52.3 (127) | 44.5 (93) | 41.7 (58) | |
| Fatigue rating, mean (SD) (0 = no fatigue, 10 = very severe fatigue) | 4.5 (2.5) | 5.1 (2.5) | 4.3 (2.5) | 3.9 (2.5) | <.0001 |
| Days with respiratory symptoms in past 2 weeks | 5.4 (5.5) | 7.7 (5.8) | 3.9 (4.6) | 3.6 (4.8) | <.0001 |
| Nights with respiratory symptoms in past two weeks | 2.7 (4.7) | 3.4 (5.4) | 2.5 (4.4) | 1.6 (3.5) | .002 |
| Functional limitations | 0.9 (0.7) | 1.1 (0.7) | 0.8 (0.7) | 0.7 (0.6) | <.0001 |