Diarrhea Diarrhoea: a clinical prediction rule can help reduce unnecessary stool culture for inpatients

Clinical bottom line (level 1a)

  1. Fewer than one in four hundred inpatients with diarrhoea have an enteropathogenic bacterial infection other than Clostridium difficile.
  2. A clinical prediction rule can help reduce unnecessary stool cultures.
Bauer et al: Journal of the American Medical Association 2001; 285 : 313-319
Expires October 2003

The study

Setting: 4 acute hospitals, Germany, Switzerland, Spain, UK

65 patients (aged ?, ?% male) with diarrhoea in hospital
Validation of a clinical prediction rule derived from 1735 adult inpatients (man age 49; 51% female)
Non-independent ?blinded reference standard, applied in all patients from a consecutive appropriate spectrum.
Reference standard:
  • culture of all stool samples
Diagnostic test: Selective stool culture: obtain stool culture in the presence of
  • community-acquired diarrhoea (if onset within 72 hours of admission)
  • nosocomial diarrhoea (onset after 72 hours of admission) and at least one of - aged 65 or more and pre-existing comorbidity; HIV infection; neutropenia; suspected nosocomial outbreak
  • suspected nondiarrheal manifestations of enteric infections: mesenteric lymphadenitis, acalculous cholecystitis, fever of unknown origin, polyarthritis, erythema nodosum
Perform no more than 3 examinations in total per patient.

The evidence

  • prevalence of enteropathogenic bacterial diarrhoea: 65/27000 = 0.24% (95% CI: 0.18% to 0.30%)
  • sensitivity: 97% (95% CI: 93% to 100%)
  • Applying the clinical prediction rule would have reduced unnecessary stool cultures by 47% to 62%.

Comments

  1. Neutropenia defined as < 0.5 x 10 ^9/L
  2. Co-morbidity defined as any preexisting disease that resulted in permanent altered organ function e.g. cirrhosis, end-stage renal failure, COPD, active inflammatory bowel disease, leukaemia or hemiparesis due to stroke
  3. Diarrhea defined as 3 or more soft or liquid bowel movements within 72 hours.
  4. 85% of cases were detected from the first stool culture, 5% from the second and 10% from the third.
  5. No clinical signs or symptom helped predicted patients with enteropathogenic bacterial infections.

Citation

  1. Bauer TM, Lalvani A, Fehrenbach J, et al: derivation and validation of guidelines for stool cultures for enteropathogenic bacteria other than Clostridium difficile in hospitalized adults. Journal of the American Medical Association 2001; 285 : 313-319
Search Terms: from ACP Journal Club
Contributor: Chris Ball, October 2001
Reviewer:

Clinical Question.
Patient inpatient with diarrhoea
Intervention or Exposure clinical prediction rule for stool culture
Outcome enteropathogenic bacteria cultured