Table 1. Characteristics of participants by status of fuel use and ventilation for cooking.
| Time Point | Characteristic | Group | p-Value | |||
| Neither (n = 160) | CF-only (n = 146) | V-only (n = 89) | Both (n = 287) | |||
| Baseline | Age, y | 55.5 (10.1) | 54.8 (10.0) | 54.7 (10.1) | 53.4 (9.6) | 0.17 |
| Men, number (percent) | 75 (46.9) | 73 (50.0) | 38 (42.7) | 125 (43.6) | 0.57 | |
| Participants educated <6 y, number (percent) | 150 (93.8) | 129 (88.4) | 79 (88.8) | 253 (88.2) | 0.27 | |
| With COPD, number (percent) | 16 (10.0) | 17 (11.6) | 13 (14.6) | 32 (11.1) | 0.74 | |
| Occupational exposure to dust/gases/fumes, number (percent) a | 34 (21.1) | 40 (27.6) | 23 (25.8) | 59 (20.7) | 0.39 | |
| BMI, kg/m2 | 22.4 (2.2) | 22.6 (2.7) | 22.2 (2.7) | 22.8 (2.7) | 0.24 | |
| Smoking intensity, pack-years b | 39.1 (30.4) | 33.1 (19.9) | 30.8 (24.3) | 30.1 (20.5) | 0.11 | |
| Current smoking status, number (percent) | 0.23 | |||||
| Never smoker | 95 (59.4) | 84 (57.5) | 55 (61.8) | 183 (63.8) | ||
| Ex-smoker | 5 (3.1) | 13 (8.9) | 4 (4.5) | 11 (3.8) | ||
| Current smoker | 60 (37.5) | 49 (33.6) | 30 (33.7) | 93 (32.4) | ||
| ETS exposure, number (percent) | 138 (86.3) | 126 (86.3) | 74 (83.1) | 236 (82.2) | 0.59 | |
| Self-reported poor economic status (net annual income per person<US$163.40/person), number (percent) | 12 (7.5) | 12 (8.2) | 5 (5.6) | 15 (5.2) | 0.60 | |
| Biomass exposure index c | 116.3 (69.4) | 108.5 (73.1) | 109.3 (78.8) | 108.4 (62.8) | 0.67 | |
| Living area size, m2/person | 13.2 (10.7) | 13.2 (13.9) | 10.2 (5.2) | 13.4 (11.2) | 0.10 | |
| FEV1, l | 2.20 (0.64) | 2.24 (0.63) | 2.09 (0.69) | 2.20 (0.69) | 0.43 | |
| Percent predicted FEV1 | 97.1 (20.1) | 97.0 (20.5) | 89.8 (22.1) | 93.3 (20.5) | 0.016 | |
| FVC, l | 2.80 (0.74) | 2.86 (0.70) | 2.72 (0.77) | 2.79 (0.78) | 0.56 | |
| Percent predicted FVC | 103.7 (17.5) | 104.3 (18.7) | 98.3 (17.9) | 100.1 (18.1) | 0.015 | |
| FEV1/FVC ratio, percent | 78.3 (9.4) | 78.0 (9.9) | 76.4 (10.7) | 78.4 (9.7) | 0.36 | |
| At the end of the study | Smoking intensity, pack-years d | 47.5 (31.2) | 42.1 (21.6) | 41.1 (27.0) | 39.6 (22.0) | 0.24 |
| Current smoking status, number (percent) | 0.45 | |||||
| Never smoker | 93 (58.1) | 84 (57.5) | 55 (61.8) | 181 (63.1) | ||
| Ex-smoker | 14 (8.8) | 22 (15.1) | 8 (9.0) | 29 (10.1) | ||
| Current smoker | 53 (33.1) | 40 (27.4) | 26 (29.2) | 77 (26.8) | ||
| ETS exposure, number (percent) e | 118 (75.6) | 116 (80.0) | 66 (74.2) | 221 (78.4) | 0.68 | |
Data are mean (SD) unless otherwise indicated. CF-only: only use of clean fuels; V-only: only improved ventilation; Both: both use of clean fuels and improved ventilation; Neither: neither use of clean fuels nor improved ventilation.
There were nine participants whose data were missing, including two participants in Group Both, one participant in Group CF-only, and six participants in Group Neither.
Calculated for 265 smokers (only one female), including 65 participants in Group Neither, 62 in Group CF-only, 34 in Group V-only, and 104 in Group Both.
Biomass exposure index was defined as the number of years before baseline multiplied by the hours of exposure to biomass for cooking per day.
Calculated for 269 smokers (only one female), including 67 participants in Group Neither, 62 in Group CF-only, 34 in Group V-only, and 106 in Group Both.
There were ten participants whose data were missing, including five participants in Group Both, one participant in Group CF-only, and four participants in Group Neither.