title: The yield of stool testing in hospital-onset diarrhea: Has evidence changed practice?
abstract: BACKGROUND
  Aside from examination for Clostridium difficile, the yield of stool testing in hospital-onset diarrhea is poor. Clinical practice guidelines discourage overzealous stool testing in patients with diarrhea that develops after the third hospital day. However, the adoption of this recommendation into clinical practice is limited. Furthermore, the effect of microbiology laboratory improvements on hospital-onset diarrhea testing is largely unknown.
  
  
  METHODS
  A retrospective cohort study was conducted in a university-affiliated community-hospital and included all adult inpatients who developed diarrhea after hospitalization.
  
  
  RESULTS
  132 adult patients (53% female) developed diarrhea after hospitalization in 2013. The cohort's mean age was 55.6 years. 46.2% of patients developed diarrhea in the first 3 days of hospitalization. Testing for parasites was negative in all examined 67 samples. Testing for C. difficile was positive in 13 cases (10.8%) out of 120 tested samples. Testing for other pathogens was positive in 1 sample (Campylobacter) out of 129 samples. Stool samples tested in the first 3 days of hospitalization were more likely to be positive (64.3 vs 35.7%, p = 0.1). Change in management was reported in 9 out of 14 patients (64.3%) with positive stool testing compared with 31 out of 118 patients (26.3%) with negative stool testing, p = 0.01.
  
  
  CONCLUSIONS
  Despite improvements in stool samples' testing, the yield continues to be low, especially in hospital-onset diarrhea past the third hospital day. Physicians' embracement of the '3-day rule' continues to be poor.
authors.affiliation: Department of Internal Medicine, Texas Tech University Health Sciences Center , Amarillo, TX , USA.
authors.forename: Omar N
authors.initials: ON
authors.lastname: Nadhem
authors.forename: Adnanul
authors.initials: A
authors.lastname: Karim
authors.forename: Mohammed G
authors.initials: MG
authors.lastname: Al-Janabi
authors.forename: Aiman A
authors.initials: AA
authors.lastname: Shoker
authors.forename: Mansoor
authors.initials: M
authors.lastname: Mehmood
authors.forename: Faisal A
authors.initials: FA
authors.lastname: Khasawneh
mesh_terms: D000328:Adult; D000368:Aged; D016360:Clostridioides difficile / Q000302:isolation & purification; D015331:Cohort Studies; D003428:Cross Infection / Q000453:epidemiology / Q000382:microbiology*; D003967:Diarrhea / Q000453:epidemiology / Q000382:microbiology*; D005243:Feces / Q000382:microbiology*; D006760:Hospitalization / Q000706:statistics & numerical data*; D006801:Humans; D007297:Inpatients / Q000706:statistics & numerical data; D008875:Middle Aged; D012189:Retrospective Studies; D012307:Risk Factors; D012477:Salmonella enteritidis / Q000302:isolation & purification; D013997:Time Factors
keywords: Clostridium difficile; Diarrhea; hospital-onset; laboratory utilization