Tuesday, October 20, 2015: 2:00 PM
Grand Ballroom B (Hyatt Regency St. Louis at the Arch)

Natasha Nanwa, MSc1, Beate Sander2, Murray D Krahn, MD, MSc, FRCPC3, Nick Daneman, MD, MSc4, Hong Lu, MSc, PhD5, Peter C. Austin, PhD5, Anand Govindarajan, MD, MSc6, Laura Rosella, MPH, PhD7, Suzanne Cadarette, MSc, PhD1 and Jeffrey Kwong2, (1)Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, ON, Canada, (2)Public Health Ontario, Toronto, ON, Canada, (3)Toronto Health Economics and Technology Assessment (THETA) Collaborative, University of Toronto, Toronto, ON, Canada, (4)Institute of Health Policy, Management and Evaluation, University of Toronto, Toronto, ON, Canada, (5)Institute for Clinical Evaluative Sciences, Toronto, ON, Canada, (6)Mount Sinai Hospital, Toronto, ON, Canada, (7)Dalla Lana School of Public Health, Toronto, ON, Canada

To assess attributable health and cost outcomes associated with community-acquired Clostridium difficile infection (CDI). 


We conducted a population-based matched cohort study. Between 01/01/2003 and 31/12/2010, we identified incident cases of community-acquired CDI (infected patients) defined as patients with the ICD-10-CA code A04.7 present during: an emergency department (ED) visit (principal/non-principal diagnosis, index date: ED registration date); a non-elective hospital admission (principal/non-principal diagnosis) with length of stay ≤2 days (index date: hospital admission date); or a non-elective hospital admission (principal diagnosis) with CDI symptoms (e.g., diarrhea) documented during a physician or ED visit within two weeks prior to the hospital admission date (index date: physician visit or ED registration date). We followed infected patients until 31/12/2011. Infected patients were matched 1:1 without replacement to uninfected subjects in the general population using propensity score and hard matching on a set of baseline characteristics. Health outcomes included colectomy within 1-year post index date and all-cause mortality. Cost outcomes (from the healthcare payer perspective in 2012 Canadian dollars) included phase-specific costs, up-to-1-year costs unadjusted for survival, and up-to-3-year costs adjusted for survival.


We identified 7,903 patients infected with community-acquired CDI. The crude mean annual incidence was 7.8 per 100,000. The mean age was 63.5 years (standard deviation=22.0) and 63% were female. The relative risk for undergoing a colectomy within 1-year post index date was 5.53 (95% confidence interval [CI], 3.30-9.27) and the relative risk for mortality within 1-year post index date was 1.58 (95%CI, 1.44-1.75). Infected patients had 1.3- to 5.3-fold higher mean costs versus uninfected subjects. The mean attributable cost (adjusted for survival) of an incident community-acquired CDI patient was $8,881 (95%CI: $7,951-$9,904) in the first year, $2,663 in the second year, and $2,480 in the third year. Mean attributable costs were generally higher among those diagnosed in 2010 (possibly due to a virulent strain), males, those aged ≥65 years, and those who died within 1-year after the index date.


Community-acquired CDI is associated with a substantial health and economic burden. CDI leads to a greater risk for colectomy and all-cause mortality, and higher short- and long-term healthcare costs. This is the first study to evaluate the costs of community-acquired CDI using a large population-based sample and to evaluate long-term costs of community-acquired CDI.