Identification of target risk groups for population-based Clostridium difficile infection prevention strategies using a population attributable risk approach.

Objectives: We aimed to determine risk factors associated with Clostridium difficile infection (CDI) and assess the contributions of these factors on CDI burden.

Methods: We conducted a 1:4 matched case-control study using a national claims dataset. Cases were incident CDI without a history of CDI in the previous 84 days, and were age- and sex-matched with control patients. We ascertained exposure, defined as a history of morbidities and drug use within 90 days. The population attributable risk (PAR) percent for risk factors was estimated using odds ratios (ORs) obtained from the case-control study.

Results: Overall, the strongest CDI-associated risk factors, which have significant contributions to the CDI burden as well, were the experience of gastroenteritis (OR=5.08, PAR%=17.09%) and use of antibiotics (OR=1.69, PAR%=19.00%), followed by the experiences of female pelvic infection, irritable bowel syndrome, inflammatory bowel disease, and pneumonia, and use of proton-pump inhibitors (OR=1.52-2.37, PAR%=1.95-2.90).

Conclusions: The control of risk factors that had strong association with CDI and affected large proportions of total CDI cases would be beneficial for CDI prevention. We suggest performing CDI testing for symptomatic patients with gastroenteritis and implementing antibiotics stewardship.