Table 3.
Derived equations for various spirometric parameters of male and female subjects
| Males | |
| VC (R2 = 0.745, RSD = 0.41225) | |
| Predicted | ˗1.163 + (-0.035)A + 0.039H |
| LLN | ˗2.148 + (-0.037)A + 0.034H |
| FVC (R2 = 0.837, RSD = 0.29524) | |
| Predicted | ˗ 0.848 + (-0.034)A + 0.035H |
| LLN | ˗1.487 + (-0.035)A + 0.031H |
| FEV1 (R2 = 0.821, RSD = 0.28328) | |
| Predicted | ˗0.834 + (-0.031)A + 0.031H |
| LLN | ˗1.448 + (-0.032)A + 0.028H |
| FEV ratio (R2 = 0.08, RSD = 4.6897) | |
| Predicted | 82.448 + (-0.120)A + 0.038H |
| LLN | 72.288 + (-0.206)A + (0.029)H |
| FEV3 (R2 = 0.845, RSD = 0.27565) | |
| Predicted | ˗0.613 + (-0.033)A + 0.033H |
| LLN | ˗1.210 + (-0.034)A + 0.029H |
| FEV6 Same as for FVC | |
| MMEF (R2 = 0.450, RSD = 0.91509) | |
| Predicted 3.830 + (-0.051)A + 0.017H | |
| LLN | 1.997 + (-0.054)A + 0.015H |
| PEFR (R2 = 0.573, RSD = 1.11787) | |
| Predicted | ˗4.199 + (-0.054)A + 0.091H |
| LLN | ˗6.621 + (-0.061)A + 0.078H |
| MVV (R2 = 0.594, RSD = 20.3577) | |
| Predicted | 34.221 + (-1.378)A + 0.915H |
| LLN | 20.883 + (-1.408)A + 0.671H |
| FIVC (R2 = 0.707, RSD = 0.37060) | |
| Predicted | ˗1.407 + (-0.027)A + 0.035H |
| LLN | ˗2.210 + (-0.029)A + 0.031H |
| FIV1 (R2 = 0.661, RSD = 0.36884) | |
| Predicted | ˗1.572 + (-0.023)A + 0.034H |
| LLN | ˗2.371 + (-0.025)A + 0.029H |
| PIF (R2 = 0.458, RSD = 0.88486) | |
| Predicted | ˗2.366 + (-0.029)A + 0.066H |
| LLN | ˗4.283 + (-0.035)A + 0.056H |
| Females | |
| VC (R2 = 0.688, RSD = 0.40299) | |
| Predicted | ˗2.980 + (-0.029)A + 0.044H |
| LLN | ˗3.975 + (-0.032)A + 0.038H |
| FVC (R2 = 0.876, RSD = 0.16623) | |
| Predicted | ˗1.578 + (-0.022)A + 0.032H |
| LLN | ˗1.988 + (-0.023)A + 0.030H |
| FEV1 (R2 = 0.761, RSD = 0.21655) | |
| Predicted | ˗1.861 + (-0.018)A + 0.031H |
| LLN | ˗2.195 + (-0.019)A + 0.028H |
| FEV ratio (R2 = 0.034, RSD = 5.6592) | |
| Predicted | 60.815 + (-0.044A) + 0.177H |
| LLN | 48.554 + (-0.054A) + 0.152H |
| FEV3 (R2 = 0.860, RSD = 0.17413) | |
| Predicted | ˗2.374 + (-0.020)A + 0.036H |
| LLN | ˗2.804 + (-0.021)A + 0.033H |
| FEV6 (R2 = 0.876, RSD = 0.16555) | |
| Predicted | ˗1.521 + (-0.022)A + 0.032H |
| LLN | ˗1.930 + (-0.023)A + 0.029H |
| MMEF (R2 = 0.552, RSD = 0.73682) | |
| Predicted | ˗3.830 + (-0.041)A + 0.059H |
| LLN | ˗5.548 + (-0.045)A + 0.059H |
| PEFR (R2 = 0.611, RSD = 0.77743) | |
| Predicted | ˗4.986 + (-0.045)A + 0.082H |
| LLN | ˗5.903 + (-0.049)A + 0.070H |
| MVV (R2 = 0.550, RSD = 10.2106) | |
| Predicted | 3.752 + (-0.578)A + 0.752H |
| LLN | 5.102 + (-0.939)A + 0.579H |
| FIVC (R2 = 0.676, RSD = 0.27872) | |
| Predicted | ˗1.201 + (-0.020)A + 0.028H |
| LLN | ˗1.888 + (-0.022)A + 0.024H |
| FIV1 (R2 = 0.575, RSD = 0.30378) | |
| Predicted | ˗0.762 + (-0.018)A + 0.023H |
| LLN | ˗1.511 + (-0.020)A + 0.019H |
| PIF (R2 = 0.564, RSD = 0.62244) | |
| Predicted | ˗3.928 + (-0.030)A + 0.066H |
| LLN | ˗5.464 + (-0.034)A + 0.057H |
R 2 coefficient of determination, RSD residual standard deviation, LLN lower limit of normal, A age in years, H height in centimetres, VC vital capacity (Liters), FVC forced vital capacity (Liters), FEV 1 forced expiratory volume in one second (Liters), FEV ratio FEV1/FVC%, FEV 3 forced expiratory volume in three seconds (Liters), FEV 6 forced expiratory volume in six seconds (Liters), PEFR peak expiratory flow rate(Liters/sec), MMEF maximal mid expiratory flow (Liters/sec), MVV maximal voluntary ventilation (Liters/min), FIVC forced inspiratory vital capacity (Liters), FIV 1 forced inspiratory volume in one second (Liters), PIF peak inspiratory flow (Liters/sec)