Table 1 Characteristics of study participants (N = 16,832)

Age, years, mean (SD)

62.0 (10.6)

63.4 (11.0)

65.6 (10.5)

< 0.001

Sex (%)

0.068

 Male

6,876 (87.5)

2,428 (86.0)

5,393 (87.7)

 Female

983 (12.5)

395 (14.0)

757 (12.3)

Area, metropolitan (%)

4,515 (57.5)

1,606 (56.9)

3,454 (56.2)

0.312

Income (%)

< 0.001

 Medical Aid

571 (7.3)

211 (7.5)

301 (4.9)

 ≤ 30th

1,863 (23.7)

685 (24.3)

1,374 (22.3)

 31st – 70th

2,763 (35.2)

977 (34.6)

2,138 (34.8)

 > 70th

2,558 (32.5)

910 (32.2)

2,230 (36.3)

 Unknown

104 (1.3)

40 (1.4)

107 (1.7)

BMI (%)

< 0.001

 Underweight (< 18.5 kg/m²)

602 (7.7)

232 (8.2)

410 (6.7)

 Normal (18.5–23 kg/m²)

3,142 (40.0)

1,184 (41.9)

2,290 (37.2)

 Overweight (23–25 kg/m²)

1,778 (22.6)

591 (20.9)

1,444 (23.5)

 Obesity (> 25 kg/m²)

2,337 (29.7)

816 (28.9)

2,005 (32.6)

 Unknown

0 (0.0)

0 (0.0)

1 (0.0)

Drinking status (%)

< 0.001

 No

3,268 (41.6)

1,284 (45.5)

3,314 (53.9)

 Yes

4,588 (58.4)

1,538 (54.5)

2,834 (46.1)

 Unknown

3 (0.0)

1 (0.0)

2 (0.0)

Regular physical activity (%)

1,000 (12.7)

405 (14.3)

907 (14.7)

0.002

Pack-year at Exam 1, mean (SD)

15.0 (7.3)

16.9 (6.8)

14.3 (7.6)

< 0.001

Daily smoking intensity at Exam 1 (%)

< 0.001

 Light

1,592 (20.3)

419 (14.8)

1,767 (28.7)

 Moderate

4,515 (57.5)

1,541 (54.6)

3,421 (55.6)

 Heavy

1,752 (22.3)

863 (30.6)

962 (15.6)

Medication*

 ICS (%)

711 (9.0)

299 (10.6)

689 (11.2)

< 0.001

 LABA (%)

1,004 (12.8)

395 (14.0)

865 (14.1)

0.055

 LAMA (%)

1,305 (16.6)

524 (18.6)

1,344 (21.9)

< 0.001

Severe exacerbation (%)*

479 (6.1)

215 (7.6)

665 (10.8)

< 0.001

Comorbidities*

 CCI, mean (SD)

2.4 (2.2)

2.5 (2.3)

2.7 (2.4)

< 0.001

 Pulmonary tuberculosis (%)

175 (2.2)

82 (2.9)

185 (3.0)

0.01

 Interstitial lung disease (%)

112 (1.4)

42 (1.5)

155 (2.5)

< 0.001

 Bronchiectasis (%)

208 (2.6)

78 (2.8)

272 (4.4)

< 0.001

 Pneumonia (%)

796 (10.1)

314 (11.1)

898 (14.6)

< 0.001