Table 1.
Participant characteristics stratified by COPD status, reported as mean (SD) for continuous data
| COPD (n=109) | Controls (n=135) | P-value | |
|---|---|---|---|
|
| |||
| Demographics | |||
| Age (years) | 65.7 (7.1) | 58.5 (9.0) | <0.001 |
| Gender: female/male | 42/67 | 89/46 | <0.001 |
| Employment status: employed/unemployed/retired | 28/12/69 | 72/7/56 | <0.001 |
| Household incomea (£):<£18,000/£18,000–30,999/£31,000–51,999/£52,000–99,999/≥£100,000 | 40/31/17/6/0 | 15/39/37/34/4 | <0.001 |
| Respiratory health | |||
| Smoking status: current/former/never | 18/78/12 | 8/60/67 | <0.001 |
| Pack years (median [IQR]) | 38.9 (29.0) | 10.6 (18.0) | <0.001 |
| FEV1 (L) | 2.0 (0.7) | 2.8 (0.6) | <0.001 |
| FEV1%pred | 76.2 (17.8) | 107.0 (17.9) | <0.001 |
| FVC (L) | 3.6 (1.0) | 3.9 (0.8) | 0.016 |
| FEV1/FVC | 56.0 (11.2) | 72.8 (6.3) | <0.001 |
| mMRC score (median [IQR]) | 1 (1) | 0 (1) | <0.001 |
| Perceived general health | |||
| General health index value | 0.775 (0.181) | 0.893 (0.109) | <0.001 |
| General health VAS score (median [IQR]) | 80 (25) | 90 (15) | <0.001 |
| Body composition | |||
| BMI (kg/m2) | 28.6 (5.6) | 26.9 (5.2) | 0.016 |
| Percentage body fat | 28.8 (8.6) | 29.7 (8.2) | 0.426 |
| Waist circumference (cm) | 99.9 (13.9) | 89.9 (14.4) | <0.001 |
| Physical function | |||
| ISWT (m) | 387.4 (158.5) | 580.1 (189.5) | <0.001 |
| QMVC (kg) | 34.9 (13.2) | 38.3 (14.7) | 0.067 |
| Grip strength (kg) | 35.7 (10.9) | 36.0 (10.5) | 0.820 |
| Usual walking speed: slow/average/fairly brisk/brisk | 29/63/15/2 | 3/73/56/3 | <0.001 |
Note:
a
15 (13.7%) COPD patients and six (4.5%) controls did not provide an answer.
Abbreviations: BMI, body mass index; FEV1%pred, FEV1 percentage predicted; ISWT, incremental shuttle walk test; IQR, interquartile range; mMRC, modified Medical Research Council; QMVC, quadriceps maximal voluntary contraction; VAS, visual analog scale.