Ambulatory-treated Clostridium difficile infection: a comparison of community-acquired vs. nosocomial infection.

The purpose of this study was to identify the clinical outcomes of ambulatory-treated Clostridium difficile infection (CDI) and risk factors associated with community-associated CDI (CA-CDI). Adult patients diagnosed with CDI in the institutional or ambulatory-care setting between 1 April 2005 and 30 April 2011, with no other CDI diagnosis in the previous 180 days, and who purchased an ambulatory, anti-CDI agent within 7 days of CDI diagnosis were included. A total of 1201 patients were included with 914 (76%) and 287 (24%) identified with CA-CDI and nosocomial CDI (N-CDI), respectively. Patients with N-CDI were more likely to have had a recurrent CDI (P = 0·043) and died from any cause (P < 0·001). Patients with CA-CDI were younger, healthier, and had fewer traditional risk factors compared to patients with N-CDI. To prevent CA-CDI, clinicians should be aware that patients at risk for CA-CDI are unique from those at risk for N-CDI.