A Longitudinal Study of Smokers and Nonsmokers
Chest(1980)
摘要
Three hundred forty-two smokers and nonsmokers, first tested at an emphysema screening center in Portland in 1971/72, were followed-up for five to six years, using a respiratory symptom questionnaire, Spirometric tests and the single breath N2 test. Subjects were tested three times during the study period. Since the major objective of this study was to evaluate the role of the single breath N2 test in identifying the smoker most likely to progress to chronic airflow obstruction, only nonsmokers and smokers without clinical airflow obstruction (defined as an abnormal 1-sec forced expiratory volume [FEV1]) were included.
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