Table 1.
Participant characteristics of study population, and comparisons between groups.
| Characteristics | All | Pre-frail with poor performance | Pre-frail with non-poor performance | Non-frail with non-poor performance c | p-value |
|---|---|---|---|---|---|
| Number of subjects, n (%) | 125 | 31 (25.6) | 69 (57) | 21 (17.4) | |
| Demographics variables | |||||
| Age (years), mean (±SD) | 66 (8.4) | 69 (7.7) | 67 (7.0) | 59 (9.9)a,b | <0.001 |
| Male, n (%) | 105 (86.8) | 27 (87.1) | 61.0 (88.4) | 17 (81.0) | 0.676 |
| Clinical and pulmonary variables | |||||
| BMI (kg/m2), mean (±SD) | 29.0 (5) | 28.3 (5.4) | 29.8 (4.9) | 27.4 (4.8) | 0.955 |
| Number Comorbidities, median (IQR) | 3 (2,5) | 3 (3) | 3 (3) | 2 (2)a,b | <0.001 |
| Smoking pack-years, mean (±SD) | 57.4 (25.0) | 66.0 (26.9) | 59.0 (23.6) | 40.0 (18.2)a,b | <0.001 |
| Current smoker, n (%) | 38(31.4) | 10 (32.3) | 22 (31.9) | 6 (28.6) | 0.953 |
| Total number of exacerbations, median (IQR) | 2 (2) | 3 (2) | 2 (1) | 2 (2.5) | 0.972 |
| Total number of severe exacerbations, median (IQR) | 1 (1) | 1 (1) | 1 (1) | 0 (1) a | 0.024 |
| FEV1 (% predicted), mean (±SD) | 51.4 (16.6) | 46.0 (17.5) | 53.2 (16.5) | 53.6 (14.5) | 0.367 |
| CAT ≥10, n (%) | 85 (70.2) | 29 (93.5) | 43 (62.3) a | 13 (61.9) a | 0.004 |
| Dyspnea score (mMRC), median (IQR) | 1 (1) | 2 (1) | 1 (0.5) | 1.5 (1) | <0.001 |
| GOLD stage, n (%) | 0.093 | ||||
| A | 24 (19.8) | 2 (6.5) | 17 (24.6) | 5 (23.8) | |
| B | 20 (16.5) | 6 (19.4) | 11 (15.9) | 3 (14.3) | |
| C | 11 (9.1) | 0 (0) | 8 (11.6) | 3 (14.3) | |
| D | 66 (54.5) | 23 (74.2) | 33 (47.8) | 10 (47.6) | |
| Domiciliary oxygen therapy, n (%) | 27 (22.3) | 11 (35.5) | 14 (20.3) | 2 (9.5) | 0.073 |
| NIV at home, n (%) | 13 (10.7) | 5 (16.1) | 7 (10.1) | 1 (4.8) | 0.418 |
| Non-pulmonary variables | |||||
| Quadriceps strength (kg), mean (±SD) | 15.9 (2.8) | 14.3 (3.0) | 16.1 (2.5) a | 17.8 (2.1)a,b | <0.001 |
| Gait speed (m/s), mean (±SD) | 0.94 (0.2) | 0.7 (0.1) | 0.9 (0.1) a | 1.1 (0.2)a,b | <0.001 |
| 5-STS time (s), mean (±SD) | 15.3 (7.4) | 22.7 (11.3) | 12.9 (1.7) a | 12.0 (2.8) a | <0.001 |
| SPPB score, mean (±SD) | 9.9 (1.7) | 7.8 (1.3) | 10.5 (1.1) a | 10.8 (1.1) a | <0.001 |
| % activities with limitations, mean (±SD) | 20.3 (17.1) | 31.6 (20.4) | 18.3 (15.0) a | 10.1 (6.8) a | <0.001 |
ap < .05 respect pre-frail poor performance.
bp < .05 respect pre-frail non-poor performance.
cOnly 21/25 non-frail with non-poor performance patients are shown (4/25 had poor performance).
SD: standard deviation; BMI: body mass index; FEV1: forced expiratory volume in 1 s; CAT: COPD Assessment Test; mMRC: modified British Medical Research Council; IQR: interquartile range; 5-STS: five-repetition sit-to-stand test; SPPB: short physical performance battery.