Background
Methods
Study populations
Study measures
Questionnaire
Definitions
Statistical analysis
Results
Characteristics | Total n = 30,874 | |
---|---|---|
Sex, n (%) | Female | 17,230 (55.8) |
Male | 13,644 (44.2) | |
Smoking status, n (%) | Never-smoker | 15,308 (49.6) |
Former smoker | 8479 (27.5) | |
Current smoker | 7065 (22.9) | |
Missing information | 22 (0.07) | |
Age in years, mean (± SD) | 56.1 (±11.3) | |
Age in decades, n (%) | 40–49 | 10,828 (35.1) |
50–59 | 9038 (29.3) | |
60–69 | 6466 (20.9) | |
70–79 | 3691 (12.0) | |
≥80 | 851 (2.8) | |
Geographical altitude in meters, mean (± SD) | 521.8 (±687.8) | |
Geographical altitude, n (%) | 0–250 | 15,823 (51.3) |
250–500 | 3437 (11.1) | |
500–750 | 2737 (8.9) | |
750–1500 | 4899 (15.9) | |
>1500 | 3978 (12.9) |
Site | Study | Altitude (m) | COPD prevalence (%) | |
---|---|---|---|---|
1 | Bergen, Norway | BOLD | 5 | 12.5 |
2 | Mumbai, India | BOLD | 5 | 6.8 |
3 | Barcelona, Spain | EPI-SCAN | 10 | 10.7 |
4 | Vigo, Spain | EPI-SCAN | 10 | 4.8 |
5 | Manila, Philippines | BOLD | 11 | 8.5 |
6 | CapeTown, South Africa | BOLD | 14 | 19.0 |
7 | Guangzhou, China | BOLD | 18 | 7.8 |
8 | Baranquilla, Colombia | Prepocol | 18 | 3.6 |
9 | Sydney, Australia | BOLD | 19 | 10.9 |
10 | Nampicuan, Philippines | BOLD | 20 | 14.3 |
11 | Uppsala, Sweden | BOLD | 21 | 9.3 |
12 | London, England | BOLD | 22 | 16.0 |
13 | Sevilla, Spain | EPI-SCAN | 23 | 4.9 |
14 | Adana, Turkey | BOLD | 28 | 14.3 |
15 | Vancouver, Canada | BOLD | 32 | 12.3 |
16 | Montevideo, Uruguay | Platino | 35 | 11.9 |
17 | Sousse, Tunisia | BOLD | 38 | 5.0 |
18 | Tartu, Estonia | BOLD | 39 | 7.0 |
19 | Maastricht, Netherlands | BOLD | 53 | 18.2 |
20 | Reykjavik, Iceland | BOLD | 54 | 11.0 |
21 | Lisbon, Portugal | BOLD | 56 | 11.5 |
22 | Hannover, Germany | BOLD | 59 | 8.9 |
23 | Cordoba, Spain | EPI-SCAN | 133 | 9.4 |
24 | Krakow, Poland | BOLD | 214 | 13.7 |
25 | Oviedo, Spain | EPI-SCAN | 239 | 11.0 |
26 | Ife, Nigeria | BOLD | 266 | 6.9 |
27 | Lexington, USA | BOLD | 291 | 15.2 |
28 | Salzburg, Austria | BOLD | 424 | 15.8 |
29 | Huesca, Spain | EPI-SCAN | 457 | 7.2 |
30 | Vic, Spain | EPI-SCAN | 497 | 5.7 |
31 | Santiago, Chile | Platino | 543 | 9.7 |
32 | Pune, India | BOLD | 560 | 6.1 |
33 | Requena (Valencia), Spain | EPI-SCAN | 588 | 6.2 |
34 | Madrid La Princesa, Spain | EPI-SCAN | 648 | 10.9 |
35 | Madrid La Paz, Spain | EPI-SCAN | 648 | 6.6 |
36 | Sao Paulo, Brazil | Platino | 800 | 11.1 |
37 | Burgos, Spain | EPI-SCAN | 864 | 3.9 |
38 | Caracas, Venezuela | Platino | 950 | 8.5 |
39 | Bucaramanga, Colombia | Prepocol | 960 | 5.3 |
40 | Cali, Colombia | Prepocol | 995 | 5.6 |
41 | Medellin, Colombia | Prepocol | 1538 | 10.6 |
42 | Srinagar, India | BOLD | 1587 | 16.4 |
43 | Mexico City, Mexico | Platino | 2240 | 3.8 |
44 | Bogotá, Colombia | Prepocol | 2640 | 5.2 |
Characteristics | Altitude <1500 m | Altitude >1500 m |
p-value |
---|---|---|---|
n = 26,896 |
n = 3978 | ||
COPD prevalence (%) | 9.9 | 8.5 | <0.005 |
Mean FEV1 (Litre, SD) | 2.66 (0,85) | 2.45 (0.78) | 0.010 |
Mean FVC (Litre, SD) | 3.47 (1.05) | 3.20 (0.90) | <0.001 |
Mean FEV1/FVC (SD) | 76.8 (8.8) | 76.2 (10.0) | <0.001 |
Sex – female (%) | 54.9 | 62.1 | <0.001 |
Age (Mean, SD) | 56.2 (11.3) | 55.1 (11.3) | <0.001 |
Never-smoker (%) | 48.6 | 56.5 | <0.001 |
Dusty job (%) | 36.1 | 24.5 | <0.001 |
Tuberculosis (%)a
| 3.5 | 0.4 | <0.001 |
Education >12 years (%) | 23.6 | 9.5 | <0.001 |
Prior lung function test, ever (%)b
| 28.1 | 4.1 | <0.001 |
Self-reported diagnosis of COPD (%) | 5.1 | 3.9 | <0.001 |
Proportion of correct prior diagnosis of COPD (%) | 37.0 | 31.2 | 0.158 |
Proportion of undiagnosed COPD (%) | 80.8 | 85.8 | 0.029 |
Variable | OR (crude) (95% CI) |
p-value | OR (multivariate model) (95% CI) |
p-value | |
---|---|---|---|---|---|
Altitude | <1500 | 1 | 1 | ||
>1500 | 0.85 (0.75; 0.95) | 0.005 | 0.90 (0.80; 1.02) | 0.111 | |
Sex | Male | 1 | 1 | ||
Female | 0.73 (0.68; 0.79) | <0.001 | 0.94 (0.86; 1.02) | 0.119 | |
Age in years | 1.04 (1.04; 1.04) | <0.001 | 1.05 (1.04; 1.05) | <0.001 | |
Years of education | >12 | 1 | 1 | ||
9–12 | 1.24 (1.11; 1.39) | <0.001 | 1.16 (1.03; 1.30) | 0.015 | |
<9 | 1.48 (1.33; 1.64) | <0.001 | 1.24 (1.12; 1.39) | <0.001 | |
Smoking status | Never | 1 | 1 | ||
Former | 1.97 (1.79; 2.16) | <0.001 | 1.78 (1.61; 1.97) | <0.001 | |
Current | 2.78 (2.53; 3.05) | <0.001 | 3.40 (3.08; 3.76) | <0.001 | |
Dusty job | 1.37 (1.27; 1.48) | <0.001 | 1.18 (1.09; 1.29) | <0.001 |