Table 2—

Prediction equations for the forced expiratory volume in one second (FEV1), forced vital capacity (FVC), and FEV1/FVC% of healthy never-smokers in the present study

ConstantAge yrsHeight (cm)Estimated LLN#R2Residual sd
FEV1 L
 Male−0.865−0.044 (−0.076–−0.0013)0.041 (0.014–0.069)−0.910.300.55
 Female0.333−0.041 (−0.067–−0.015)0.029 (0.008–0.051)−0.590.570.36
FVC L
 Male−2.75−0.044 (−0.082–−0.006)0.058 (0.026–0.091)−1.070.320.65
 Female−1.34−0.041 (−0.075–−0.007)0.044 (0.016–0.072)−0.780.540.47
FEV1/FVC%
 Male95.2−0.30 (−0.64–0.04)−9.570.065.8
 Female107.4−0.44 (−0.83–0.06)−10.730.136.5
  • The 95% confidence intervals for the individual coefficients are in parenthesis.

  • #: given value is 1.65×residual sd.

  • Calculation of the estimated lower limit of normal (LLN) for an individual will then be: predicted–1.65×residual sd