Prediction Equations of Pulmonary Function Parameters Derived from the Forced Expiratory Spirogram for Healthy Adults over 50 years old in rural area

Kim, Won Young; Kim, Kwang Hyun; Youn, Boung Han; Lee, Seung Uk; Cho, Chul Hyun; Choi, Jin Su; Kim, Hun Nam

Abstract

BACKGROUND: The studies on prediction equations of pulmonary function parameters for adults in Korea have been performed in a reference population mainly consisted of young and middle ages. So they included a relatively few elderly who conducted pulmonary function test frequently in clinic. We established prediction equations of pulmonary function parameters for healthy adults over 50 years old in rural area and compared this results with those of other studies. Therefore we attempted to consider normative values of pulmonary function tests for elderly in Korea. METHOD: Five hundred thirty-three women and men over 50 years old in rural area were participated. A "healthy" subgroup of 110 women and 32 men were identified by excluding those who had conditions that negatively influenced pulmonary function. We derived prediction equations for FVC, FEV1, and FEV1% by multiple linear regression method from their age, heights and weights in each sex.
RESULTS
Prediction equations for FVC and FEV1 in each sex were derived as follows Male; FVC (L) = 0.02488Height(cm) - 0.0269Age(years) + 0.493 FEV1(L) = 0.01874Weight(kg) - 0.0282Age(years) + 2.906 Female; FVC(L) = 0.02160Height(cm) - 0.0192Age(years) - 0.0125 FEV1 (L) = 0.01720Height(cm) - 0.0194Age(years) + 0.3890 Prediction equations for FEV1 % were not derived because FEV1 % didn't have statistically significant terms. Comparing Predicted values that were calculated by substitution into the equations of various studies of mean values of age, heights and weights from this study, FVC and FEV1 values in men of this study were lower than those of other studies. In women, FVC and VEV1 values of this study were as similar as or lower than those of the study conducted for healthy elderly blacks in U.S.A respectively.
CONCLUSION
We have got prediction equations of pulmonary function parameters which were driven from forced expiratory spirogram in adults over 50 years old in rural area. Predicted values of this study were lower than those of other studies which were conducted in Korea. So we consider that the study for spirometry reference values for elderly Korean using the method compatible with ATS recommendation need to be conducted more frequently forward.