title: Epidemiology and healthcare costs of incident Clostridium difficile infections identified in the outpatient healthcare setting.
abstract: OBJECTIVE
  To describe the epidemiology and healthcare costs of Clostridium difficile infection (CDI) identified in the outpatient setting.
  
  
  METHODS
  Population-based, retrospective cohort study.
  
  
  METHODS
  Kaiser Permanente Colorado and Kaiser Permanente Northwest members between June 1, 2005, and September 30, 2008.
  
  
  METHODS
  We identified persons with incident CDI and classified CDI by whether it was identified in the outpatient or inpatient healthcare setting. We collected information about baseline variables and follow-up healthcare utilization, costs, and outcomes among patients with CDI. We compared characteristics of patients with CDI identified in the outpatient versus inpatient setting.
  
  
  RESULTS
  We identified 3,067 incident CDIs; 56% were identified in the outpatient setting. Few strong, independent predictors of diagnostic setting were identified, although a previous stay in a nonacute healthcare institution (odds ratio [OR], 1.45 [95% confidence interval (CI), 1.13-1.86]) was statistically associated with outpatient-identified CDI, as was age from 50 to 59 years (OR, 1.64 [95% CI, 1.18-2.29]), 60 to 69 years (OR, 1.37 [95% CI, 1.03-1.82]), and 70 to 79 years (OR, 1.36 [95% CI, 1.06-1.74]), when compared with persons aged 80-89 years.
  
  
  CONCLUSIONS
  We found that more than one-half of incident CDIs in this population were identified in the outpatient setting. Patients with outpatient-identified CDI were younger with fewer comorbidities, although they frequently had previous exposure to healthcare. These data suggest that practitioners should be aware of CDI and obtain appropriate diagnostic testing on outpatients with CDI symptoms.
authors.affiliation: Center for Health Research, Kaiser Permanente Northwest, Portland, Oregon 97227, USA. jennifer.l.kuntz@kpchr.org
authors.forename: Jennifer L
authors.initials: JL
authors.lastname: Kuntz
authors.forename: Eric S
authors.initials: ES
authors.lastname: Johnson
authors.forename: Marsha A
authors.initials: MA
authors.lastname: Raebel
authors.forename: Amanda F
authors.initials: AF
authors.lastname: Petrik
authors.forename: Xiuhai
authors.initials: X
authors.lastname: Yang
authors.forename: Micah L
authors.initials: ML
authors.lastname: Thorp
authors.forename: Steven J
authors.initials: SJ
authors.lastname: Spindel
authors.forename: Nancy
authors.initials: N
authors.lastname: Neil
authors.forename: David H
authors.initials: DH
authors.lastname: Smith
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000554:Ambulatory Care Facilities; D002648:Child; D002675:Child, Preschool; D016360:Clostridioides difficile / Q000302:isolation & purification*; D003120:Colorado / Q000453:epidemiology; D016001:Confidence Intervals; D004761:Enterocolitis, Pseudomembranous / Q000191:economics* / Q000453:epidemiology*; D005260:Female; D005102:Health Expenditures / Q000639:trends*; D006296:Health Services / Q000191:economics / Q000706:statistics & numerical data; D006801:Humans; D007223:Infant; D008297:Male; D008875:Middle Aged; D015205:Northwestern United States / Q000453:epidemiology; D016017:Odds Ratio; D017063:Outcome Assessment, Health Care; D011159:Population Surveillance; D012189:Retrospective Studies; D055815:Young Adult