Utilization of influenza immunization in adults with Crohn's disease - A longitudinal, population-based study

Background: The incidence of vaccine-preventable disease is increasing. Several guidelines recommend annual influenza vaccination for patients with inflammatory bowel disease. Methods: Using the Business Objects database of Clalit Health Services in the Tel Aviv district we identified all patients older than 18 years with a diagnosis of Crohn's disease (CD) on December 31, 2005. This cohort was followed until December 31, 2012. Subjects without inflammatory bowel disease older than 50 years served as controls. The uptake of annual influenza vaccination was recorded. Results: The study included 515 patients with CD (267 [51.8%] men, age 48.9±17.5 years, disease duration 142.7±56.9 months) and 2960 controls (1262 [42.6%] men, P<0.01, age 68.9±11.1 years, P<0.01). The mean number of influenza vaccines received from 2006 to 2012 was 2.08±2.46 and 3.40±2.71 in CD and controls, respectively (P<0.01). Uptake was higher in patients with CD aged 50 to 59 years and 60 to 69 years, compared with controls (0.45±0.04 versus 0.24±0.01, P<0.01 and 0.64±0.06 versus 0.50±0.01, P = 0.04, respectively). Vaccination uptake increased significantly over time in both groups (P<0.01). Predictors of vaccination in CD included age, female sex, immunosuppression, and cardiovascular disease. Conclusions: Uptake of influenza vaccination in CD has increased over the past 7 years, and among subjects older than 50 years, uptake remains higher in age-matched controls. Nevertheless, overall uptake remains low, particularly in young males.