Serial studies of 100 patients with chronic airway obstruction in London and Chicago

One hundred patients with chronic airway obstruction, 50 in Chicago and 50 in London, were studied by standardized techniques in 1961. The results of the initial studies, previously reported, showed that the patients in the two cities were similar; using clinical and physiological criteria based on pathological studies, the patients were divided into three types—emphysematous type A, bronchial type B, and an indeterminate type X. The patients …