CAPNET (Community Acquired Pneumonia NETwork) was established as one of the competence networks funded by the Federal Ministry of Education and Research in 2002. The central project Z2 covers areas of epidemiology, data management and statistics and health services research. Only few epidemiological studies have analysed risk factors for CAP and even less information is available on parameters which are associated with an increased risk of CAP recurrency. Therefore the aim of this analysis was to identify predictors of recurrent CAP.
A standardised questionnaire was distributed to patients who were recruited in the CAPNet between November 2002 and October 2003. The instrument covers questions on the medical history, potential risk factors and the vaccination status. Patients who developed CAP for the first time were compared to those with recurrent CAP in a case-control approach. The data of 302 patients with an average age of 55 years (SD 18, were analysed (46% female). Of these 121 (38.5%) gave a history of at least one prior CAP. After control for age, sex, and smoking status, a history of a chronic lung disease (OR 2.0, 1.2-3.5) and difficulties to swallow (OR 4.1,) remained statistically significant risk factors for CAP recurrency in a logistic regression model. The risk factors identified for CAP seem not to be identical with risk factors of CAP recurrency. The consideration of these specific medical conditions may help to decrease the risk of CAP recurrences.