Objective: To study the incidence, severity, and mortality rates of pneumonia in a cohort of chronic obstructive pulmonary disease (COPD) patients monitored over 3 years.
Patients and methods: A total of 596 patients diagnosed with COPD according to spirometric criteria were included in the study. The variables assessed were mortality and severity according to the Pneumonia Severity Index (PSI) for community-acquired pneumonia (CAP).
Results: Of the 596 patients included in the study, 75 (12.6%) developed at least 1 episode of pneumonia during the 3 years of the study. The overall incidence of pneumonia was 55.1 per 1000 person-years. There were 88 episodes in 75 patients. COPD severity, evaluated based on percentage of predicted FEV1, was mild in 9 patients, moderate in 24, and severe in 42. Seventy-six (86.3%) episodes were CAP and 12 (13.6%) were acquired in hospital. Fourteen CAP cases corresponded to PSI group V, 28 to group IV, 20 to group III, and 14 to groups I and II. Overall mortality was 12.5% (11/88). The mortality rate was 41.7% (5/12) for nosocomial cases and 7.8% (6/76) for CAP cases (OR, 6.67; 95% confidence interval, 1.65-26.93). Assessing CAP mortality by level of severity, we found that the mortality rate was 35.7% (5/14) for group V and 3.5% (1/28) for group IV. No deaths occurred among patients in the other severity groups.
Conclusions: The incidence of pneumonia in COPD patients is high. More than half the cases of CAP (55.2%) in our COPD patients were classified in PSI risk groups IV and V.