Table 5.
Correlation and regression analysis
| FEV1% | FVC% | FEV1/FVC% | |
|---|---|---|---|
| Duration of exposure to biomass | |||
| Correlation coefficient (r) | −0.810 | −0.620 | −0.769 |
| P | <0.001 | <0.001 | <0.001 |
| Regression coefficient (95% CI) | −1.35 (−1.46-−1.24) | −0.62 (−0.71-−0.54) | −0.75 (−0.83-−0.69) |
| Biomass index | |||
| Correlation coefficient (r) | −0.663 | −0.456 | −0.634 |
| P | <0.001 | <0.001 | <0.001 |
| Regression coefficient (95% CI) | −0.43 (−0.49-−0.40) | −0.18 (−0.22-−0.14) | −0.25 (−0.28-−0.21) |
| PM1 (μg/m3) | |||
| Correlation coefficient (r) | −0.529 | −0.374 | −0.494 |
| P | <0.001 | <0.001 | <0.001 |
| Regression coefficient (95% CI) | −0.048 (−0.056-−0.039) | −0.020 (−0.026-−0.015) | −0.026 (−0.031-−0.021) |
| PM2.5 (μg/m3) | |||
| Correlation coefficient (r) | −0.533 | −0.378 | −0.497 |
| P | <0.001 | <0.001 | <0.001 |
| Regression coefficient (95% CI) | −0.043 (−0.051-−0.036) | −0.019 (−0.024-−0.014) | −0.024 (−0.028-−0.019) |
| PM10 (μg/m3) | |||
| Correlation coefficient (r) | −0.534 | −0.380 | −0.497 |
| P | <0.001 | <0.001 | <0.001 |
| Regression coefficient (95% CI) | −0.039 (−0.046-−0.032) | −0.017 (−0.021-−0.012) | −0.021 (−0.025-−0.017) |
PFT=Pulmonary function tests, LPG=Liquefied petroleum gas, PM=Particulate matter, CI=Confidence interval, FVC=Forced vital capacity, FEV1=Forced expiratory volume in 1 s