Parameter | Equations | r2 | see |
<21 yrs | |||
FVC# | 0.04202H+0.09678A−4.322 | 0.90 | 0.46 |
Lower limit of normal | 0.0370H+0.09678A−4.322 | 0.91 | |
FEV1# | 0.03569H+0.09030A−3.683 | 0.90 | 0.46 |
Lower limit of normal | 0.0310H+0.09030A−3.683 | 0.92 | |
FEV1/FVC % | 0.011935H−0.13572A+88.2983 | 0.02 | 3.57 |
Lower limit of normal | 0.101108H−0.13572A+88.2983 | ||
PEF¶ | 0.07238H+0.246A−7.720 | 0.81 | 1.26 |
Lower limit of normal | 0.058H+0.246A−7.720 | 0.91 | |
FEF25–75¶ | 0.03310H+0.150A−3.523 | 0.84 | 0.59 |
Lower limit of normal | 0.0270H+0.150A−3.523 | 0.87 | |
FEF25¶ | 0.04621H+0.287A−5.082 | 0.82 | 1.06 |
Lower limit of normal | 0.034H+0.287A−5.082 | 0.90 | |
FEF50¶ | 0.03646H+0.1799A−3.8492 | 0.82 | 0.733 |
Lower limit of normal | 0.02796H+0.1799A−3.8492 | 0.84 | |
FEF75¶ | 0.02376H+0.0512A−2.3791 | 0.70 | 0.488 |
Lower limit of normal | 0.01917H+0.0512A−2.3791 | 0.85 | |
≥21 yrs | |||
FVC# | 0.05651H−0.0252A−4.093 | 0.52 | 0.53 |
Lower limit of normal | 0.052H−0.0252A−4.093 | 0.78 | |
FEV1# | 0.045302H−0.02566A−2.78204 | 0.56 | 0.43 |
Lower limit of normal | 0.040619H−0.02566A−2.78204 | 0.76 | |
FEV1/FVC % | −0.0978H−0.104A+107.21 | 0.15 | 3.04 |
Lower limit of normal | −0.124H−0.104A+107.21 | 0.36 | |
PEF¶ | 0.07759H−0.0435A−1.369 | 0.15 | 1.96 |
Lower limit of normal | 0.061H−0.0435A−1.369 | 0.19 | |
FEF25–75¶ | 0.02625H−0.0360A+1.782 | 0.32 | 0.76 |
Lower limit of normal | 0.020H−0.0360A+1.782 | 0.47 | |
FEF25¶ | 0.05913H−0.0347A+0.280 | 0.15 | 1.586 |
Lower limit of normal | 0.04513H−0.0347A+0.280 | 0.21 | |
FEF50¶ | 0.03357H−0.0301A+1.423 | 0.19 | 1.0 |
Lower limit of normal | 0.025H−0.0301A+1.423 | 0.33 | |
FEF75¶ | 0.01563H−0.0273A+0.582 | 0.36 | 0.50 |
Lower limit of normal | 0.011H−0.0273A+0.582 | 0.58 |
FVC: forced vital capacity
FEV1: forced expiratory volume in one second
PEF: peak expiratory flow
FEF25–75: expiratory flow from 25–75% of the vital capacity
FEF25, FEF50, FEF75: instantaneous expiratory flows at 25%, 50% and 75% of FVC, respectively; H: height in cm
A: age in years
r2: coefficient of determination
see: standard error of the estimate
#: volumes are in L
¶: flows are in L·s−1