Pulmonary function testing in a general medical practice.

This study examined the feasibility and yield of spirometric screening in a general medicine clinic. Each of 354 randomly selected patients answered a questionnaire on respiratory symptoms and performed pulmonary function tests. Pulmonary testing required approximately two minutes and cost 95 cents per patient. Former smokers who stopped smoking because of symptoms displayed a higher prevalence of abnormalities than expected, and life-long smokers a lower prevalence (P less than 0.001). Fifty-three percent of current smokers had an abnormal pulmonary function test, and forty-two percent of these had no severe pulmonary symptoms. Pulmonary function tests performed in an outpatient clinic are rapid and expensive. Such tests demonstrate a large number of abnormalities which can be used to encourage smoking cessation.