Oral corticosteroids and the risk of serious infections in patients with elderly-onset inflammatory bowel diseases.

Objectives: Systemic corticosteroids are among the most common anti-inflammatory treatments in elderly-onset inflammatory bowel disease (IBD) patients. Steroid use and older age each independently predisposes to infections, and infections increase mortality in hospitalized older IBD patients. Therefore, our objective was to examine the risk of serious infections in elderly-onset IBD patients treated with oral corticosteroids, and explore how the timing of exposure affects the risk estimates.

Methods: Using the health-care databases of the province of Quebec, Canada, we conducted a population-based cohort study with a nested case-control analysis. Incident IBD patients aged ≥66 years were identified. Conditional logistic regression was performed to estimate crude and adjusted rate ratios (aRRs) with 95% confidence intervals (CIs).

Results: We identified 3,522 elderly-onset patients, of which 564 cases with serious infections were identified during a mean 4.4 years of follow-up (incidence rate 3.7 per 100 per year) and matched to 2,646 controls. The rate of serious infections was significantly higher in those exposed to oral corticosteroids any time during the previous 6-month period compared with those nonexposed (aRR 2.3; 95% CI 1.8-2.9). Those currently exposed (within 45 days) had a higher risk (aRR 2.8; 95% CI 2.1-3.7). The residual effect of oral corticosteroids remained marginally statistically significant up to the 90-day period before the index date (aRR 1.7; 95% CI 1.0-2.7).

Conclusions: We found an excess relative risk for serious infections in elderly-onset IBD patients on oral corticosteroid therapy. Those with current exposure demonstrated a higher vulnerability to infections.