Differences in sociodemographic characteristics, lifestyle factors and environmental exposures across the three chronic obstructive pulmonary disease (COPD) groups identified by cluster analysis
| Group 1 n=126 | Group 2 n=125 | Group 3 n=91 | p Value | |
| Sociodemographic characteristics | ||||
| Gender: female, n (%) | 8 (6.4) | 11 (8.8) | 5 (5.5) | 0.601 |
| Age (years), mean (SD) | 67.4 (8.8) | 68.8 (8.1) | 67.4 (9.0) | 0.346 |
| Low (IV, V) socioeconomic status, n (%) | 94 (79.0) | 97 (82.2) | 68 (85.0) | 0.552 |
| Lifestyle factors | ||||
| Smoking status: | ||||
| Never, n (%) | 0 (0) | 2 (1.6) | 0 (0) | 0.418 |
| Former, n (%) | 77 (63.1) | 84 (68.9) | 59 (67.8) | |
| Current, n (%) | 45 (36.9) | 36 (29.5) | 28 (32.2) | |
| Age at onset of smoking (years), mean(SD) | 15.3 (4.4) | 16.2 (4.8) | 16.9 (6.9) | 0.104 |
| Age at quitting smoking (years), mean (SD) | 60.7 (9.1) | 57.0 (11.6) | 60.3 (10.1) | 0.068 |
| Time since quitting smoking (years), median (P25–P75) | 1 (0–11) | 1 (0–15) | 1 (0–10) | 0.291 |
| Pack-years smoking, mean (SD) | 68.6 (39.4) | 59.4 (36.8) | 79.4 (39.8) | 0.001 |
| Smoking duration (years), mean (SD) | 45.8 (10.0) | 42.8 (13.5) | 44.5 (11.4) | 0.121 |
| Smoking intensity (pack/day), mean (SD) | 1.2 (0.9) | 1.1 (0.9) | 1.4 (1.0) | 0.098 |
| Usual physical activity (kcals/week), median (P25–P75) | 4508 (2412–8640) | 6270 (4060–8757) | 6366 (2655–9900) | 0.020 |
| Glucid intake (%), median (P25–P75) | 39.9 (34.9–44.4) | 38.7 (34.6–43.1) | 37.9 (31.9–42.6) | 0.276 |
| Protein intake (%), median (P25–P75) | 19.7 (17.5–22.2) | 19.1 (17.5–22.3) | 19.8 (17.6–21.5) | 0.878 |
| Lipid intake (%), median (P25–P75) | 36.0 (32.0–39.4) | 34.1 (31.1–38.3) | 34.1 (30.1–38.3) | 0.141 |
| Fruit intake (g/d), median (P25–P75) | 223 (147–327) | 269 (176–373) | 238 (160–350) | 0.093 |
| Vegetable intake (g/d), median (P25–P75) | 291 (218–398) | 295 (219–369) | 243 (196–345) | 0.204 |
| Environmental exposures | ||||
| Childhood exposure to wood or charcoal smoke, n (%) | 98 (77.8) | 106 (84.8) | 68 (74.7) | 0.160 |
| Occupational exposure to vapours, gases, dust and fums | ||||
| No/low exposure, n (%) | 51 (46.4) | 34 (30.9) | 25 (22.7) | 0.060 |
| Moderate exposure, n (%) | 28 (28.0) | 42 (42.0) | 30 (30.0) | |
| High exposure, n (%) | 30 (30.9) | 38 (39.2) | 29 (29.9) | |
| Distance to the nearest high traffic road: | ||||
| 0–50 m, n (%) | 99 (38.1) | 93 (35.8) | 68 (26.2) | 0.881 |
| 51–200 m, n (%) | 19 (35.2) | 21 (38.9) | 14 (25.9) | |
| >201 m, n (%) | 6 (27.3) | 9 (40.9) | 7 (31.8) | |