[Causes of death and risk factors for mortality in patients with severe chronic obstructive pulmonary disease]

Abstract

Objective: The objective of this study was to assess the causes of death and risk factors for mortality in a cohort of patients with severe chronic obstructive pulmonary disease (COPD).

Patients and methods: We studied 203 patients with severe COPD (forced expiratory volume in 1 second [FEV(1)] <50%), who were attended in our respiratory department day hospital (2001-2006). Clinical variables were recorded on inclusion, and clinical course and causes of death were retrospectively reviewed.

Results: The mean (SD) age of patients was 69 (8) years and the mean FEV(1) was 30.8% (8.2%). One-hundred and nine patients died (53.7%); death was attributed to respiratory causes in 72 (80.9%), with COPD exacerbation being the most frequent specific cause within this category (48.3%). During follow-up, 18.7% required admission to the intensive care unit (ICU). Survival at 1, 3, and 5 years was 80%, 53%, and 26%, respectively. The multivariate analysis showed that mortality was associated with age, stage IV classification according to the Global Initiative for Chronic Obstructive Lung Disease (GOLD), cor pulmonale, and hospital admission during the year prior to inclusion. Need for admission to the ICU during follow-up was a factor independently associated with higher mortality.

Conclusions: Mortality in patients with severe COPD was high and exacerbation of the disease was one of the most frequent causes of death. Age, GOLD stage, cor pulmonale, prior admission to hospital, and need for admission to the ICU during follow-up were independent predictors of mortality.