Prediction equations for healthy elderly European males
| Equation | R2 | rsd | |
| FVC L | 0.0001572H2–0.00000268A3+0.223 | 0.477 | 0.4458 |
| FEV1 L | 0.0001107H2–0.0445A+2.886 | 0.464 | 0.3797 |
| FEV1/FVC % | −0.00198A2+87.472 | 0.083 | 5.2655 |
| FEV0.5 L | 0.02615H–0.0372A+0.538 | 0.411 | 0.3305 |
| FEV2 L | 0.0001331H2–0.00000283A3+0.499 | 0.488 | 0.4066 |
| FEV3 L | 0.0001414H2–0.0000028A3+0.420 | 0.488 | 0.4174 |
| FEV6 L | 0.0001501H2–0.000298A2+0.869 | 0.483 | 0.4288 |
| FEV1/FEV6 % | −0.0000172A3+85.536 | 0.086 | 5.0040 |
| FEF25% L·s−1 | 0.04185H–0.137A+8.947 | 0.226 | 1.5178 |
| FEF50% L·s−1 | 0.03174H–0.0754A+3.176 | 0.170 | 1.0573 |
| FEF75% L·s−1 | 0.009789H–0.0184A+0.355 | 0.163 | 0.2776 |
| PEF L·s−1 | 0.07092H–0.000939A2+0.347 | 0.221 | 1.7378 |
| FEF75–25% L·s−1 | 0.02635H–0.0604A+2.042 | 0.219 | 0.7241 |
| FEF75–85% L·s−1 | 0.007765H–0.00948A–0.229 | 0.149 | 0.1779 |
| TC25–50% s | 0.00005571A2+0.153 | 0.045 | 0.2041 |
| MTT s | 0.00002282A2+0.223 | 0.054 | 0.0760 |
| AEX L2·s−1 | 0.0007148H2–0.379A+18.788 | 0.397 | 3.3119 |
| PIF L | 0.0002211H2–0.0909A+4.621 | 0.247 | 1.2465 |
| MIF50% L·s−1 | 0.0002133H2–0.0856A+4.128 | 0.221 | 1.2759 |
| FIV1 L | 0.0001585H2–0.0526A+2.592 | 0.373 | 0.5967 |
The lower limit of the normal is computed as: predicted value–1.645×residual standard deviation (rsd)
R2: adjusted coefficient of determination
FVC: forced vital capacity
FEV1: forced expiratory volume in one second
FEV0.5: forced expiratory volume in 0.5 seconds
FEV2: forced expiratory volume in two seconds
FEV3: forced expiratory volume in three seconds
FEV6: forced expiratory volume in six seconds
FEF25%: forced expiratory flow when 25% of the forced expiratory capacity has been exhaled
FEF50%: forced expiratory flow when 50% of the forced expiratory capacity has been exhaled
FEF75%: forced expiratory flow when 75% of the forced expiratory capacity has been exhaled
PEF: peak expiratory flow
FEF75–25%: forced mid-expiratory flow
FEF75–85%: forced mid-expiratory flow between 75–85% of FVC
TC25–50%: time constant between 25–50% of FVC
MTT: mean transit time
AEX: area delineated by forced expiratory flow/volume curve
PIF: peak inspiratory flow
MIF50%: forced inspiratory flow when 50% of the vital capacity has been inhaled
FIV1: forced inspiratory volume in one second
H: height in cm
A: age in yrs