The risk of community-acquired pneumonia among 9803 patients with coeliac disease compared to the general population: a cohort study

Background: Patients with coeliac disease are considered as individuals for whom pneumococcal vaccination is advocated.

Aim: To quantify the risk of community-acquired pneumonia among patients with coeliac disease, assessing whether vaccination against streptococcal pneumonia modified this risk.

Methods: We identified all patients with coeliac disease within the Clinical Practice Research Datalink linked with English Hospital Episodes Statistics between April 1997 and March 2011 and up to 10 controls per patient with coeliac disease frequency matched in 10-year age bands. Absolute rates of community-acquired pneumonia were calculated for patients with coeliac disease compared to controls stratified by vaccination status and time of diagnosis using Cox regression in terms of adjusted hazard ratios (HR).

Results: Among 9803 patients with coeliac disease and 101 755 controls, respectively, there were 179 and 1864 first community-acquired pneumonia events. Overall absolute rate of pneumonia was similar in patients with coeliac disease and controls: 3.42 and 3.12 per 1000 person-years respectively (HR 1.07, 95% CI 0.91-1.24). However, we found a 28% increased risk of pneumonia in coeliac disease unvaccinated subjects compared to unvaccinated controls (HR 1.28, 95% CI 1.02-1.60). This increased risk was limited to those younger than 65, was highest around the time of diagnosis and was maintained for more than 5 years after diagnosis. Only 26.6% underwent vaccination after their coeliac disease diagnosis.

Conclusions: Unvaccinated patients with coeliac disease under the age of 65 have an excess risk of community-acquired pneumonia that was not found in vaccinated patients with coeliac disease. As only a minority of patients with coeliac disease are being vaccinated there is a missed opportunity to intervene to protect these patients from pneumonia.