Table 3
Multiple linear regression predictive equations for lung function outcomes FVC, FEV1, PEF, and FEF75–25*
| Variable | β | 95% CI for β | p value |
|---|---|---|---|
| *Ethnic origin automatically included in the model. Other terms retained if p<0.05 (smoking p<0.10) or higher order term in covariate included. | |||
| Predictive equation for outcome FVC (l) | |||
| Constant | 2.218 | (−1.487 to 5.924) | 0.24 |
| Gender (additive effect of being female compared to male) | −0.075 | (−0.127 to −0.024) | 0.004 |
| Ethnic origin (additive effect of being Asian compared to white) | −0.226 | (−0.280 to −0.172) | <0.001 |
| Standing height (m) | −3.337 | (−8.872 to 2.198) | 0.24 |
| Standing height2 (m2) | 2.250 | (0.182 to 4.318) | 0.033 |
| Chest volume calculated as a box (l) | 0.053 | (0.032 to 0.074) | <0.001 |
| n = 247; adjusted R2 = 0.78 | |||
| Predictive equation for outcome FEV1 (l) | |||
| Constant | 3.346 | (−0.208 to 6.899) | 0.065 |
| Ethnic origin (additive effect of being Asian compared to white) | −0.179 | (−0.231 to −0.128) | <0.001 |
| Standing height (m) | −4.966 | (−10.274 to 0.343) | 0.067 |
| Standing height2 (m2) | 2.769 | (0.785 to 4.753) | 0.006 |
| Chest volume calculated as a box (l) | 0.031 | (0.011 to 0.500) | 0.002 |
| n = 247; adjusted R2 = 0.72 | |||
| Predictive equation for outcome PEF (l/s) | |||
| Constant | −3.746 | (−4.879 to −2.613) | <0.001 |
| Ethnic origin (additive effect of being Asian compared to white) | −0.170 | (−0.344 to 0.003) | 0.055 |
| Standing height (m) | 4.835 | (3.602 to 6.068) | <0.001 |
| Chest height (cm) | 0.0565 | (0.006 to 0.107) | 0.028 |
| n = 251; adjusted R2 = 0.45 | |||
| Predictive equation for outcome FEF75–25 (l/s) | |||
| Constant | −1.797 | (−2.641 to −0.952) | <0.001 |
| Ethnic origin (additive effect of being Asian compared to white) | −0.195 | (−0.344 to −0.046) | 0.011 |
| Standing height (m) | 3.026 | (2.414 to 3.637) | <0.001 |
| Asthma | −0.228 | (−0.415 to −0.041) | 0.017 |
| Mother smokes 1–10 cigarettes per day | −0.105 | (−0.405 to 0.195) | 0.49 |
| Mother smokes 11+ cigarettes per day | −0.315 | (−0.562 to −0.068) | 0.013 |
| n = 263; adjusted R2 = 0.30 | |||
