Baseline characteristics of study population and dropout/excluded participants
| Variables | Study population n=277 | Dropout/excluded participants n=293 | p Value |
|---|---|---|---|
| Male sex | 180 (65.0) | 174 (59.4) | 0.168 |
| Age, year | 60.9±12.2 | 55.6±14.1 | <0.001 |
| Cigarettes smoked daily, N | 22.9±12.4 | 26.8±13.5 | <0.001 |
| Duration of smoking, year | 38.5±13.1 | 33.6±13.1 | <0.001 |
| Brinkman Index | 876.3±567.9 | 871.6±534.2 | 0.919 |
| TDS score | 7.7±1.6 | 7.8±1.6 | 0.565 |
| Exhaled CO, ppm | 13.8±9.4 | 15.6±11.9 | 0.053 |
| Body mass index, kg/m2 | 23.2±4.5 | 22.9±4.1 | 0.438 |
| FEV1, % predicted | 75.7±20.2 | 78.4±19.9 | 0.105 |
| FVC, % predicted | 82.8±17.4 | 85.4±16.7 | 0.079 |
| FEV1/FVC, % | 74.9±13.3 | 75.5±11.3 | 0.159 |
| Diseases (self-reported) | |||
| Mental disorder | 79 (28.5) | 88 (30.0) | 0.691 |
| Diabetes mellitus | 49 (17.7) | 48 (16.4) | 0.678 |
| Cardiovascular disease | 60 (21.7) | 35 (12.0) | 0.002 |
| COPD | 49 (17.7) | 32 (10.9) | 0.020 |
| Bronchial asthma | 34 (12.3) | 37 (12.6) | 0.898 |
| Cancer | 22 (7.9) | 28 (9.6) | 0.495 |
| SGRQ score | |||
| Symptoms | 41.8±24.1 | 40.7±21.9* | 0.593 |
| Activity | 35.6±26.3 | 33.7±25.2* | 0.370 |
| Impact | 20.4±18.3 | 19.3±17.9* | 0.505 |
| Total | 28.5±19.3 | 27.2±18.1* | 0.410 |
Data are presented as number (%) or mean±SD.
*Baseline SGRQ was available for 277 participants.
COPD, chronic obstructive pulmonary disease; FEV1, forced expiratory volume in 1 s; FVC, forced vital capacity; SGRQ, St. George's Respiratory Questionnaire; TDS, Tobacco Dependence Screener test.