Table 4.
Multiple regression analyses of pulmonary function data†
| Variable | FVC (L) | FEV 1(L) | FEV1/FVC (%) | MMF (L/S) | ||||
|---|---|---|---|---|---|---|---|---|
| Beta [SE‡] | p | Bet [SE] | p | Beta [SE] | p | Beta [SE] | p | |
| Model 1: by work tasks | ||||||||
| Task# | ||||||||
| WP vs. W | 0.122 [0.166] | 0.47 | 0.113 [0.165] | 0.50 | -0.148 [1.476] | 0.92 | -0.202 [0.392] | 0.61 |
| WPB vs. W | 0.267 [0.182] | 0.15 | 0.204 [0.180] | 0.26 | -1.341 [1.614] | 0.41 | -0.022 [0.429] | 0.96 |
| B vs. W | 0.129 [0.185] | 0.49 | -0.084 [0.183] | 0.65 | -5.200 [1.640] | < 0.01 | -0.845 [0.436] | 0.05 |
| Age (year) | -0.028 [0.006] | < 0.01 | -0.029 [0.006] | < 0.01 | -0.099 [0.053] | 0.07 | -0.061 [0.014] | < 0.01 |
| Height (cm) | 0.046 [0.010] | < 0.01 | 0.033 [0.010] | < 0.01 | -0.216 [0.087] | 0.01 | -0.013 [0.023] | 0.57 |
| Weight (Kg) | -0.001 [0.007] | 0.94 | 0.003 [0.007] | 0.71 | 0.065 [0.063] | 0.30 | 0.012 [0.017] | 0.37 |
| Smoking | ||||||||
| Ex-smoker vs. Never | 0.007 [0.163] | 0.97 | -0.013 [0.161] | 0.94 | -0.446 [1.442] | 0.76 | 0.158 [0.383] | 0.68 |
| Current vs. Never | -0.111 [0.122] | 0.36 | -0.139 [0.120] | 0.25 | -1.007 [1.079] | 0.35 | -0.195 [0.287] | 0.50 |
| Tea-drinking | ||||||||
| Occasional vs. Never | 0.170 [0.302] | 0.57 | 0.208 [0.299] | 0.49 | 1.257 [2.677] | 0.64 | -0.007 [0.711] | 0.99 |
| Habitual vs. Never | 0.300 [0.294] | 0.31 | 0.225 [0.291] | 0.44 | -1.091 [2.609] | 0.68 | -0.521 [0.693] | 0.45 |
| Annual work duration (month) | 0.001 [0.003] | 0.64 | 0.002 [0.003] | 0.41 | 0.035 [0.027] | 0.20 | 0.016 [0.007] | 0.03 |
| Model 2: by dust level | ||||||||
| Coarse fraction | 0.033 [0.070] | 0.64 | -0.073 [0.070] | 0.30 | -2.612 [0.615] | < 0.01 | -0.332 [0.166] | 0.04 |
| Respirable dust | -0.190 [0.466] | 0.68 | -0.265 [0.463] | 0.57 | -2.739 [4.069] | 0.50 | -0.612 [1.099] | 0.58 |
| Age (yea) | -0.028 [0.006] | < 0.01 | -0.030 [0.006] | < 0.01 | -0.104 [0.053] | 0.05 | -0.062 [0.014] | < 0.01 |
| Height (cm) | 0.045 [0.010] | < 0.01 | 0.032 [0.010] | < 0.01 | -0.230 [0.087] | 0.01 | -0.016 [0.024] | 0.49 |
| Weight (Kg) | -0.001 [0.007] | 0.88 | 0.002 [0.007] | 0.76 | 0.067 [0.062] | 0.29 | 0.014 [0.017] | 0.42 |
| Smoking | ||||||||
| Ex-smoker vs. Never | 0.046 [0.162] | 0.77 | 0.032 [0.161] | 0.84 | -0.241 [1.416] | 0.87 | 0.163 [0.382] | 0.67 |
| Current vs. Never | -0.086 [0.120] | 0.47 | -0.112 [0.119] | 0.35 | -0.912 [1.046] | 0.39 | -0.208 [0.283] | 0.46 |
| Tea-drinking | ||||||||
| Occasional vs. Never | 0.134 [0.302] | 0.66 | 0.170 [0.301] | 0.57 | 1.166 [2.643] | 0.66 | -0.026 [0.714] | 0.97 |
| Habitual vs. Never | 0.270 [0.295] | 0.36 | 0.198 [0.293] | 0.50 | -1.054 [2.574] | 0.68 | -0.520 [0.696] | 0.46 |
| Annual work duration (month) | 0.002 [0.003] | 0.57 | 0.003 [0.003] | 0.34 | 0.038 [0.026] | 0.15 | 0.016 [0.007] | 0.03 |
†FVC forced vital capacity, FEV1 1-second forced expiratory volume, MMF maximal mid-expiratory flow rate; ‡SE standard error; #W withering, WP Withering + Panning, WPB Withering + Panning + Ball-Rolling, B Ball-Rolling