Seven hundred and fifty men were screened for the presence of mild chronic obstructive pulmonary disease, and 134 subjects were enrolled in a therapy program. The findings of follow-up interviews, physical examinations, and laboratory tests were correlated with the screening results. Among those completing six months of therapy, there was a marked improvement of respiratory symptoms, but no significant change in pulmonary function. Cessation of cigarette smoking was most closely associated with the symptomatic improvement.
Baker TR, Oscherwitz M, Corlin R, Jarboe T, Teisch J, Nichaman MZ. Screening & Obstructive Treatment Program Pulmonary Disease for Mild Chronic. JAMA. 1970;214(8):1448-1455. doi:10.1001/jama.1970.03180080030006