title: Epidemiology and outcomes of community-acquired Clostridium difficile infections in Medicare beneficiaries.
abstract: BACKGROUND
  The incidence of community-acquired Clostridium difficile (CACD) is increasing in the United States. Many CACD infections occur in the elderly, who are predisposed to poor outcomes. We aimed to describe the epidemiology and outcomes of CACD in a nationally representative sample of Medicare beneficiaries.
  
  
  METHODS
  We queried a 5% random sample of Medicare beneficiaries (2009-2011 Part A inpatient and Part D prescription drug claims; n = 864,604) for any hospital admission with a primary ICD-9 diagnosis code for C difficile (008.45). We examined patient sociodemographic and clinical characteristics, preadmission exposure to oral antibiotics, earlier treatment with oral vancomycin or metronidazole, inpatient outcomes (eg, colectomy, ICU stay, length of stay, mortality), and subsequent admissions for C difficile.
  
  
  RESULTS
  A total of 1,566 (0.18%) patients were admitted with CACD. Of these, 889 (56.8%) received oral antibiotics within 90 days of admission. Few were being treated with oral metronidazole (n = 123 [7.8%]) or vancomycin (n = 13 [0.8%]) at the time of admission. Although 223 (14%) patients required ICU admission, few (n = 15 [1%]) underwent colectomy. Hospital mortality was 9%. Median length of stay among survivors was 5 days (interquartile range 3 to 8 days). One fifth of survivors were readmitted with C difficile, with a median follow-up time of 393 days (interquartile range 129 to 769 days).
  
  
  CONCLUSIONS
  Nearly half of the Medicare beneficiaries admitted with CACD have no recent antibiotic exposure. High mortality and readmission rates suggest that the burden of C difficile on patients and the health care system will increase as the US population ages. Additional efforts at primary prevention and eradication might be warranted.
authors.affiliation: Center for Outcomes Research Surgical Research Scholars Program, Department of Surgery, University of Massachusetts, Worcester, MA. Electronic address: courtney.collins@umassmemorial.org.
authors.forename: Courtney E
authors.initials: CE
authors.lastname: Collins
authors.affiliation: Center for Outcomes Research Surgical Research Scholars Program, Department of Surgery, University of Massachusetts, Worcester, MA.
authors.forename: M Didem
authors.initials: MD
authors.lastname: Ayturk
authors.affiliation: Center for Outcomes Research Surgical Research Scholars Program, Department of Surgery, University of Massachusetts, Worcester, MA.
authors.forename: Julie M
authors.initials: JM
authors.lastname: Flahive
authors.affiliation: Center for Outcomes Research Surgical Research Scholars Program, Department of Surgery, University of Massachusetts, Worcester, MA.
authors.forename: Timothy A
authors.initials: TA
authors.lastname: Emhoff
authors.affiliation: Center for Outcomes Research Surgical Research Scholars Program, Department of Surgery, University of Massachusetts, Worcester, MA.
authors.forename: Frederick A
authors.initials: FA
authors.lastname: Anderson
authors.affiliation: Center for Outcomes Research Surgical Research Scholars Program, Department of Surgery, University of Massachusetts, Worcester, MA.
authors.forename: Heena P
authors.initials: HP
authors.lastname: Santry
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D016360:Clostridioides difficile; D003015:Clostridium Infections / Q000453:epidemiology* / Q000628:therapy*; D017714:Community-Acquired Infections / Q000453:epidemiology / Q000628:therapy; D005260:Female; D006801:Humans; D008297:Male; D006278:Medicare; D016896:Treatment Outcome; D014481:United States
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