Gender differences in survival following hospitalisation for COPD

Background Chronic obstructive pulmonary disease (COPD) is a leading cause of morbidity and mortality worldwide. Gender differences in the clinical expression of COPD are increasingly recognised, but outcome differences have not been systematically examined. Gender differences in survival and rate of rehospitalisation were investigated in a large cohort of elderly patients with chronic airflow obstruction hospitalised for COPD. Methods The databases from the Quebec provincial health insurance plan were used. The study population included subjects aged >66 years who received >= 3 prescriptions for respiratory medications in any 1-year period between 1 January 1990 and 31 December 2001. The study cohort consisted of patients with a first hospitalisation for COPD, after selection into the study population. Patients were followed until death or 31 December 2003. The Kaplan-Meier method was used to estimate time to death and time to first hospitalisation for obstructive airways disease (COPD or asthma). The Cox proportional hazards model was used to determine the effect of male gender on all-cause mortality and rehospitalisation. Results The cohort consisted of 19 260 women and 23 893 men with a mean age of 77 years. 11 245 (58.4%) women and 16 754 (70.1%) men died after cohort entry. Male sex was associated with a significantly increased risk of death (adjusted HR 1.45, 95% CI 1.42 to 1.49) and with a significantly increased risk of rehospitalisation for obstructive airways disease (adjusted HR 1.12, 95% CI 1.09 to 1.15). Conclusion Mean survival and time to rehospitalisation for obstructive airways disease are significantly better for female patients.