Interpretation of Pulmonary Function Tests

This defines whether or not the person is obstructed. We define obstruction as an FEV1/FVC ratio of less than the 5th percentile of the values obtained for normals. This value varies according to the age and height of the patient but is generally between 68-77%. In patients with a low FEV1/FVC ratio, we define the severity of obstruction as the ... ................
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