FEV1 to FEV6 Ratio and the Lung Age Formula of Hansen et al

Parameters:

(1) FEV1 in liters (volume of air expired in the first second.)

(2) FEV6 in liters (volume of air expired in the first 6 seconds)

(3) age of the patient in years

actual %FEV1/FV6 =

= (measured FEV1 in liters) / (measured FEV6 in liters) * 100%

predicted %FEV1/FV6 =

= 96.9 - (0.189 * (age in years)) - (1.524 * (FEV6))

where:

• The equation is for normal never smokers. The FEV6 for the equation probably should be the expected FEV6 for the stated age rather than the value observed for the patient..

difference =

= (predicted ratio) - (actual ratio)

delta lung age =

= 4 * (difference)

apparent lung age =

= (current lung age) + (delta lung age)

An alternative approach might be to rearrange the prediction equation:

age in years =

= ((actual ratio) - 96.9 + (1.524 * (FEV6))) / (-0.189) =

= 512.7 - (8.06 * (FEV6)) - (5.29 * (actual ratio))