Table 1

Baseline characteristics of study population and dropout/excluded participants

VariablesStudy population
Dropout/excluded participants n=293p Value
Male sex180 (65.0)174 (59.4)0.168
Age, year60.9±12.255.6±14.1<0.001
Cigarettes smoked daily, N22.9±12.426.8±13.5<0.001
Duration of smoking, year38.5±13.133.6±13.1<0.001
Brinkman Index876.3±567.9871.6±534.20.919
TDS score7.7±1.67.8±1.60.565
Exhaled CO, ppm13.8±9.415.6±11.90.053
Body mass index, kg/m223.2±4.522.9±4.10.438
FEV1, % predicted75.7±20.278.4±19.90.105
FVC, % predicted82.8±17.485.4±16.70.079
FEV1/FVC, %74.9±13.375.5±11.30.159
Diseases (self-reported)
 Mental disorder79 (28.5)88 (30.0)0.691
 Diabetes mellitus49 (17.7)48 (16.4)0.678
 Cardiovascular disease60 (21.7)35 (12.0)0.002
 COPD49 (17.7)32 (10.9)0.020
 Bronchial asthma34 (12.3)37 (12.6)0.898
 Cancer22 (7.9)28 (9.6)0.495
SGRQ score
  • 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.