| Parameter | Prediction equation | sdresiduals | 1.64×sdresiduals |
| Males | |||
| FEV1 L | 3.16624H-0.02008A-1.30086 | 0.39 | 0.65 |
| FVC L | 3.81011H-0.02029A-1.84166 | 0.48 | 0.79 |
| FEV1/FVC % | -0.07029A+88.81584 | 5.66 | 9.29 |
| Females | |||
| FEV1 L | 3.25608H-0.01571A-2.02193 | 0.32 | 0.53 |
| FVC L | 3.88087H-0.01513A-2.63796 | 0.37 | 0.61 |
| FEV1/FVC % | -0.097A+90.36859 | 5.72 | 9.30 |
Lower limit of normal (5th percentile) is estimated as predicted-(1.645×sdresiduals). sdresiduals: standard deviation of the difference between measured and predicted values; FEV1: forced expiratory volume in 1 s; FVC: forced vital capacity; H: height in metres; A: age in years.