Variables | All N = 7978 | Men N = 3824 | Women N = 4154 | P value | Urban N = 6388 | Rural N = 1590 | P value |
---|---|---|---|---|---|---|---|
Airway obstruction—LLN | 673 (8.4%) | 345 (9%) | 328 (7.9%) | 0.039 | 558 (8.7%) | 115 (7.2%) | 0.029 |
Airways obstruction—FR | 289 (3.6%) | 159 (4.2%) | 130 (3.1%) | 0.008 | 243 (3.8%) | 46 (2.9%) | 0.045 |
Chronic lung disease (asthma, tuberculosis, emphysema and bronchitis)—n (%) | 346 (4.3%) | 155 (4.1%) | 191 (4.6%) | 0.127 | 302 (4.7%) | 44 (2.8%) | < 0.0001 |
History of asthma in childhood—n (%) | 949 (11.9%) | 511 (13.4%) | 438 (10.5%) | 0.028 | 756 (11.8%) | 193 (12.1%) | 0.098 |
family history of respiratory and pulmonary diseases—n (%) | 311 (3.9%) | 138 (3.6%) | 173 (4.2%) | 0.261 | 251 (3.9%) | 60 (3.8%) | 0.879 |
Symptoms | Â | Â | Â | Â | Â | Â | Â |
 Chronic cough—n (%) | 1038 (13%) | 383 (10%) | 655 (15.8%) | < 0.0001 | 937 (14.7%) | 101 (6.4%) | < 0.0001 |
 Chronic cough with phlegm—n (%) | 494 (47.6%) | 201 (52.5%) | 293 (44.7%) | 0.009 | 444 (47.4%) | 50 (49.5%) | 0.382 |
 Shortness of breath and Wheezing—n (%) | 217 (2.7%) | 75 (2%) | 142 (3.4%) | < 0.0001 | 188 (2.9%) | 29 (1.8%) | 0.007 |
Pre-bronchodilator spirometry (n = 7978) |  |  |  |  |  |  |  |
 FEV1 (L.)—mean ± SD | 2.84 ± 0.79 | 2.93 ± 0.81 | 2.76 ± 0.76 | < 0.0001 | 2.92 ± 0.78 | 2.55 ± 0.74 | < 0.0001 |
 FEV6 (L.)—mean ± SD | 2.08 ± 0.86 | 3.17 ± 0.87 | 2.99 ± 0.084 | < 0.0001 | 3.16 ± 0.85 | 2.74 ± 0.80 | < 0.0001 |
 FVC (L)—mean ± SD | 3.08 ± 0.86 | 3.18 ± 0.88 | 3.00 ± 0.84 | < 0.0001 | 3.17 ± 0.85 | 2.74 ± 0.80 | < 0.0001 |
 FEV1/FVC—mean ± SD | 92.48 ± 7.47 | 92.43 ± 7.63 | 92.52 ± 7.32 | 0.601 | 92.27 ± 7.45 | 93.33 ± 7.50 | < 0.0001 |
 FEV1/FEV6—mean ± SD | 92.39 ± 7.48 | 92.60 ± 7.45 | 92.62 ± 7.32 | 0.678 | 92.42 ± 7.36 | 93.38 ± 7.41 | < 0.0001 |
 PEF (L)—mean ± SD | 5.07 ± 2.09 | 5.28 ± 2.19 | 4.88 ± 1.96 | < 0.0001 | 5.24 ± 2.12 | 4.37 ± 1.79 | < 0.0001 |
 MVV (L/min)—mean ± SD | 99.67 ± 27.7 | 102.54 ± 28.3 | 97.02 ± 26.96 | < 0.0001 | 102.27 ± 27.55 | 89.37 ± 26.21 | < 0.0001 |
Post-bronchodilator spirometry (n = 761) |  |  |  |  |  |  |  |
 FEV1 (L.)—mean ± SD | 3.23 ± 0.21 | 3.41 ± 0.74 | 2.98 ± 0.88 | < 0.0001 | 3.35 ± 0.42 | 2.78 ± 0.81 | < 0.0001 |
 FEV6 (L.)—mean ± SD | 2.51 ± 0.74 | 3.67 ± 0.84 | 3.12 ± 0.36 | < 0.0001 | 3.41 ± 0.65 | 2.98 ± 0.63 | < 0.0001 |
 FVC (L)—mean ± SD | 3.89 ± 0.48 | 3.91 ± 0.73 | 3.84 ± 0.61 | < 0.0001 | 3.99 ± 0.53 | 2.93 ± 0.61 | < 0.0001 |
 FEV1/FVC—mean ± SD | 91.28 ± 6.94 | 91.40 ± 6.86 | 91.62 ± 6.82 | 0.687 | 91.39 ± 6.87 | 92.64 ± 6.91 | < 0.0001 |
 FEV1/FEV6—mean ± SD | 92.73 ± 7.21 | 92.92 ± 7.69 | 92.89 ± 7.41 | 0.964 | 92.68 ± 7.44 | 93.81 ± 7.48 | < 0.0001 |
 PEF (L)—mean ± SD | 5.51 ± 2.32 | 5.68 ± 2.38 | 5.21 ± 2.01 | < 0.0001 | 5.84 ± 2.39 | 4.98 ± 1.94 | < 0.0001 |
 MVV (L/min)—mean ± SD | 99.87 ± 28.1 | 102.66 ± 28.2 | 98.12 ± 28.91 | < 0.0001 | 102.69 ± 27.97 | 90.21 ± 27.31 | < 0.0001 |
Severity of COPD | Â | Â | Â | Â | Â | Â | Â |
 Mild | 138 (47.8%) | 92 (55.1%) | 46 (37.7%) | 0.003 | 111 (46.8%) | 27 (51.9%) | 0.801 |
 Moderate | 116 (40.1%) | 52 (31.1%) | 64 (52.5%) |  | 98 (41.4%) | 18 (34.6%) | |
 Severe | 28 (9.8%) | 19 (11.4%) | 9 (7.4%) |  | 22 (9.3%) | 6 (11.5%) | |
 Very severe | 7 (2.4%) | 4 (2.4%) | 3 (2.5%) |  | 6 (2.5%) | 1 (1.9%) |