Baseline characteristics and progression through pulmonary rehabilitation for the total cohort and stratified by frailty status
| All (n=816) | Not frail (n=82) | Prefrail (n=525) | Frail (n=209) | p Value | |
|---|---|---|---|---|---|
| Age (years) | 69.8 (9.7) | 67.4 (8.1) | 69.0 (9.6) | 72.6 (10.0)*† | <0.001 |
| Males, n (%) | 484 (59.3) | 49 (59.8) | 324 (61.7) | 110 (52.6) | 0.08 |
| Smoking status Current:former:never (%) | 17.9:76.5:6.6 | 9.8:84.1:6.1 | 18.7:75.0:6.3 | 15.3:77.0:7.7 | 0.45 |
| FEV1 % predicted | 48.9 (21.0) | 57.0 (22.4) | 49.0 (20.8) | 46.3 (20.1)* | <0.001 |
| MRC score | 3.3 (1.1) | 2.4 (0.8) | 3.2 (1.0) | 4.0 (0.9)*† | <0.001 |
| Age-adjusted Charlson Index | 4.3 (1.6) | 4.4 (1.6) | 4.3 (1.6) | 4.4 (1.6) | 0.57 |
| ADO score | 4.9 (1.7) | 3.6 (1.3) | 4.7 (1.6) | 6.0 (1.5)*† | <0.001 |
| BMI (kg/m) | 27.8 (6.7) | 27.2 (5.2) | 27.8 (6.5) | 27.9 (7.6) | 0.71 |
| SMI (kg/m2) | 8.47 (1.87) | 8.6 (1.9) | 8.6 (1.9) | 8.1 (1.8)*† | 0.002 |
| Sarcopenia (%) | 12.4 (10.3, 14.8) | 1.2 (0.2, 6.6) | 9.5 (7.3, 12.3) | 23.9 (18.6, 30.1) | <0.001 |
| Handgrip (kg) | 27.0 (9.9) | 33.0 (8.9) | 28.3 (9.6) | 21.3 (8.2)*† | <0.001 |
| Peak QMVC (kg) | 26.2 (10.0) | 31.0 (10.1) | 27.3 (9.6) | 21.0 (9.0)*† | <0.001 |
| QMVC % predicted | 59.1 (20.0) | 67.2 (20.6) | 60.6 (20.0) | 51.1 (16.9)*† | <0.001 |
| Below QMVC cut-point (%) | 25.9 (22.8, 29.2) | 6.4 (2.8, 14.1) | 21.4 (18.0, 25.3) | 44.0 (36.8, 51.6)*† | <0.001 |
| 4MGS (m/s) | 0.90 (0.24) | 1.11 (0.21) | 0.95 (0.19) | 0.66 (0.20)*† | <0·001 |
| ISWT (m) | 222.3 (151.3) | 375.4 (168.3) | 245.1 (135.4) | 105.0 (89.5)*† | <0.001 |
| CRQ dyspnoea score | 13.9 (5.6) | 16.4 (5.9) | 14.0 (5.7) | 12.7 (5.0)*† | <0.001 |
| CRQ fatigue score | 13.4 (5.3) | 17.6 (4.3) | 13.8 (5.2) | 10.9 (4.6)*† | <0.001 |
| CRQ emotional score | 30.6 (9.5) | 36.1 (7.7) | 31.3 (9.1) | 26.6 (9.5)*† | <0.001 |
| CRQ mastery score | 17.6 (6.0) | 21.7 (4.6) | 18.0 (5.8) | 15.0 (5.7)*† | <0.001 |
| Self-reported weekly energy expenditure (kcal) | 698.9 (1478.1) | 1878.4 (1631.0) | 1110.5 (1549.7) | 257.2 (450.0)*† | <0.001 |
| Self-reported time in moderate activity (min/week) | 279.9 (431.1) | 532.8 (491.7) | 322.6 (465.0) | 73.6 (1292)*† | <0.001 |
| CAT score | 20.7 (8.3) | 13.3 (5.6) | 20.2 (7.8) | 25.0 (7.9)*† | <0.001 |
| Katz score | 5.7 (0.7) | 5.9 (0.2) | 5.8 (0.5) | 5.4 (1.0)*† | <0.001 |
| HADS anxiety | 7.1 (4.6) | 5.2 (3.4) | 6.8 (4.4) | 8.3 (5.2)*† | <0.001 |
| HADS depression | 6.6 (3.8) | 4.1 (2.7) | 6.3 (3.7) | 8.2 (4.0)*† | <0.001 |
| Self-reported hospital admission in previous year, n (%) | 337 (41.3) | 28 (34.1) | 215 (41.0) | 94 (45.0)*† | <0.001 |
| Self-report number of exacerbations in previous year | 2.8 (3.6) | 2.1 (2.3) | 2.8 (3.9) | 3.1 (3.0)* | <0.001 |
| Frailty characteristic (% meeting criteria) | |||||
| Unintentional weight loss | 14.2 (12.0 to 16.8) | 0 | 11.8 (9.3 to 14.9) | 25.4 (19.9 to 31.7) | <0.001 |
| Exhaustion | 65.3 (62.0 to 68.5) | 0 | 68.4 (64.3 to 72.2) | 83.3 (77.6 to 87.7) | <0.001 |
| Low physical activity | 35.9 (32.7 to 39.3) | 0 | 23.8 (20.4 to 27.6) | 80.4 (74.5 to 85.2) | <0.001 |
| Slow gait speed | 24.4 (21.6 to 27.4) | 0 | 9.1 (7.0 to 11.9) | 72.2 (65.8 to 77.9) | <0.001 |
| Weak handgrip strength | 43.6 (40.3 to 47.1) | 0 | 35.8 (31.8 to 40.0) | 80.4 (74.5 to 85.2) | <0.001 |
| Pulmonary rehabilitation | |||||
| Started (% of referred) | 84.7 (82.0 to 87.0) | 80.4 (94.1) | 87.4 (84.3 to 90.0) | 76.1 (69.9 to 81.4) | <0.001 |
| Number of sessions attended | 11.4 (4.2) | 13.2 (3.0) | 11.6 (4.1) | 10.2 (4.7) | <0.001 |
| Completed (% of starters) | 83.1 (80.1 to 85.7) | 94.5 (86.7 to 97.8) | 82.8 (79.1 to 86.0) | 72.3 (64.9 to 78.7) | <0.001 |
| Completed (% of referred) | 70.3 (67.1 to 73.4) | 84.1 (74.7 to 90.5) | 74.3 (70.4 to 77.8) | 55.0 (48.2 to 61.6) | <0.001 |
Values are mean (SD) or proportions (95% CI) unless stated.
*Statistically different to non-frail group.
†Statistically different to prefrail group.
4MGS, 4-m gait speed; ADO, age, dyspnoea, and airflow obstruction; BMI, body mass index; CAT, COPD Assessment Test; CRQ, Chronic Respiratory Disease Questionnaire; HADS, Hospital Anxiety and Depression scale; ISWT, incremental shuttle walk test; kcal, kilocalorie; MRC, Medical Research Council; QMVC, quadriceps maximum voluntary contraction; SMI, skeletal muscle mass index.