Antibiotic Resistance Threats in the United States, 2013 report

Technical Appendix
Clostridium difficile
Methods
National estimates of the number of Clostridium difficile (C. difficile)
infections (CDI) requiring hospitalization or in already hospitalized
patients were obtained from the data submitted through the
Emerging Infections Program’s C. difficile surveillance in 2011, of
34 counties in 10 U.S. states (http://www.cdc.gov/hai/eip/cdiff_techinfo.html). During
2011, a total of 15,452 CDI cases were identified across the participating sites. Data on
hospitalization following CDI or at the time of infection were obtained for all cases from
8 of 10 U.S. states and from a random sample of 33% from cases from the other 2 states.
The sampled cases were used to estimate total number of hospitalizations in the 2 states
where sampling was performed. The national estimates were made using 2011 population
estimates from U.S. Census Bureau adjusting for age, gender and race distribution of
the American population. 1 Approximately 18% of cases were reported without a race
value. Multiple imputation was used to estimate the missing race based on the data that
are available and the results were summarized. The C. difficile attributable mortality was
estimated from death certificate data. 2 Trends on deaths related to C. difficile were obtained
from the CDC’s National Center for Health Statistics. 3 Estimates were rounded to two
significant digits.
References
1 Lessa FC, Mu, Y, Cohen J, Dumyati G, Farley MM, Winston L, Kast K, Holzbauer S, Meek
J, Beldavs S, McDonald LC, Fridkin SK. Presented at the IDWeek 2012, Annual Meeting
of the Infectious Disease Society of America, Society for Healthcare Epidemiology,
Pediatric Infectious Disease Society, and HIV Medical Association; San Diego, October
2012.
2 Hall AJ, Curns AT, McDonald LC, Parashar UD, Lopman BA. The Roles of Clostridium
difficile and Norovirus Among Gastroenteritis-Associated Deaths in the United States,
1999-2007. Clin Infect Dis. 2012 Jul;55(2):216–23.
3 Kochanek KD, Xu J, Murphy SL, Miniño AM, Kung HC. Deaths: Preliminary Data for 2009.
National Vital Statistics Report.
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