Differences in mortality between patients attending the emergency room services for asthma and chronic obstructive pulmonary disease

Abstract

Asthma has a more favourable prognosis than chronic obstructive pulmonary disease (COPD), based on studies including few asthmatics and few women with COPD. We assessed differences in mortality between people attending the emergency room for asthma and for COPD in a population-based cohort. We recruited all the men and women, who were residents of Barcelona (Spain) over 14 years of age, who attended emergency room services for an obstructive lung disease during the period 1985–1989. Vital status was followed up to the end of 1995. A total of 15 517 individuals (including 4555 asthmatics and 2194 females with COPD) were studied. Mortality was ascertained using a record linkage with the regional Mortality Registry. Overall, 43·6% people died during the follow-up period. Mortality was higher among individuals with COPD than with asthma, in males and females, for all causes of death, as well as for cancer, cardiovascular and respiratory causes. After adjusting for age, the relative risk (RR) of dying of a male attending for COPD and discharged home was 1·50 (1·29-1·74) in comparison with a male attending for asthma, and 3·06 (2·66-3·51) for a male attending for COPD and admitted into the hospital. Similar figures were found for females. The increased risk for patients with COPD was significantly higher than for asthma in all age groups. Both males and females with asthma have a more favourable prognosis than patients with COPD, for all age groups.