The course and prognosis of different types of chronic airflow limitation in a general population sample from Arizona: comparison with the Chicago "COPD" series.

Recently reported data from a general population study in Tucson, Arizona have shown that subjects who have an "asthmatic bronchitic" type of chronic airways obstruction have a much more benign course than equally impaired subjects who have the typical smoking-induced, and presumably emphysematous, form of disease. These data are reviewed briefly. Findings in these subjects are then compared with those in "COPD" patients enrolled in an "emphysema clinic" in Chicago many years ago; patients with asthmatic features had been systematically excluded from the Chicago series. The rate of decline in FEV1 and mortality of Arizona subjects considered to have "typical COPD" were remarkably similar to those in the Chicago series after accounting for age and initial FEV1, but Arizona subjects with features suggesting "chronic asthmatic bronchitis" had a much more favorable prognosis than either of the "COPD" groups. These different forms of chronic airways obstruction should be distinguished in clinical or epidemiologic studies of airways obstructive disorders.