Hospitalizations for vaccine preventable pneumonias in patients with inflammatory bowel disease: a 6-year analysis of the Nationwide Inpatient Sample

BACKGROUND Pneumonias are among the most common causes of hospitalization among inflammatory bowel disease (IBD) patients. Guidelines published in 2004 advocate vaccination against Streptococcus pneumoniae and influenza virus. We sought to examine trends in hospitalizations for vaccine preventable pneumonias among IBD patients since the availability of published guidelines, and to identify whether Haemophilus influenzae is a causative organism for pneumonia hospitalizations among IBD patients. METHODS This cross-sectional study on the Nationwide Inpatient Sample was used to identify admissions for pneumonias in patients with IBD between 2004 and 2009. A multivariate logistic regression analysis was performed comparing IBD patients to controls, accounting for potential confounders. RESULTS There were more admissions for S. pneumoniae pneumonia than influenza virus or H. influenzae (787, 393, and 183 respectively). Crohn's disease (CD) as well as ulcerative colitis (UC) patients did not demonstrate increased adjusted odds of hospitalization for S. pneumoniae pneumonia (1.08; confidence interval [CI] 0.99-1.17 compared to 0.93; CI 0.82-1.06 respectively). Increased adjusted odds for hospitalization for pneumonias due to influenza virus were seen among UC patients in the bottom quartile of income (1.86; CI 1.46-2.37). Adjusted odds for H. influenzae pneumonia admission in patients with UC and CD patients were increased compared to controls (1.42; CI 1.13-1.79 and 1.28; CI 1.06-1.54, respectively). CONCLUSION The study identified lowest income UC patients as having higher adjusted odds, and these patients should be targeted for influenza virus vaccination. Additionally, H. influenzae may be another vaccine preventable cause for pneumonia among IBD patients.