Criteria of impairment of pulmonary function using Japanese standard values

: According to the law of functional impairment, cases of impairment of pulmonary function are designated as 1st, 3rd and 4th grade impairment. The criteria of pulmonary function a based on Baldwin's predicted values. Recently, the Japanese Respiratory Society reported the Japanese standard values for pulmonary function. In the present study, we compared the numbers of patients classified into the three grades using the Japanese values and Baldwin's values. We found that from about 10 to 20 percent of patients appeared in a higher grade when Japanese standard values were used instead of Baldwin's values. We suggest that Japanese standard values should be used in order to judge the impairment of these patients.