Inhaled corticosteroid use in chronic obstructive pulmonary disease and the risk of hospitalization for pneumonia

Rationale: Inhaled corticosteroids are commonly prescribed to patients with chronic obstructive pulmonary disease (COPD). Objectives: To examine whether these medications might be associated with an excess risk of pneumonia. Methods: We conducted a nested case-control study within a cohort of patients with COPD from Quebec, Canada, over the period 19882003, identified on the basis of administrative databases linking hospitalization and drug-dispensing information. Each subject hospitalized for pneumonia during follow-up (case subjects) was age and time matched to four control subjects. The effect of the use of inhaled corticosteroids was assessed by conditional logistic regression, after adjusting for comorbidity and COPD severity. Measurements and Main Results: The cohort included 175,906 patients with COPD of whom 23,942 were hospitalized for pneumonia during follow-up, for a rate of 1.9 per 100 per year, and matched to 95,768 control subjects. The adjusted rate ratio of hospitalization for pneumonia associated with current use of inhaled corticosteroids was 1.70 (95% confidence interval [CI], 1.63-1.77) and 1.53 (95% Cl, 1.30-1.80) for pneumonia hospitalization followed by death within 30 days. The rate ratio of hospitalization for pneumonia was greatest with the highest doses of inhaled corticosteroids, equivalent to fluticasone at 1,000 mu g/day or more (rate ratio, 2.25; 95% Cl, 2.07-2.44). All-cause mortality was similar for patients hospitalized for pneumonia, whether or not they had received inhaled corticosteroids in the recent past (7.4 and 8.2%, respectively). Conclusions: The use of inhaled corticosteroids is associated with an excess risk of pneumonia hospitalization and of pneumonia hospitalization followed by death within 30 days, among elderly patients with COPD.