title: A bayesian approach to laboratory utilization management.
abstract: BACKGROUND
  Laboratory utilization management describes a process designed to increase healthcare value by altering requests for laboratory services. A typical approach to monitor and prioritize interventions involves audits of laboratory orders against specific criteria, defined as rule-based laboratory utilization management. This approach has inherent limitations. First, rules are inflexible. They adapt poorly to the ambiguity of medical decision-making. Second, rules judge the context of a decision instead of the patient outcome allowing an order to simultaneously save a life and break a rule. Third, rules can threaten physician autonomy when used in a performance evaluation.
  
  
  METHODS
  We developed an alternative to rule-based laboratory utilization. The core idea comes from a formula used in epidemiology to estimate disease prevalence. The equation relates four terms: the prevalence of disease, the proportion of positive tests, test sensitivity and test specificity. When applied to a laboratory utilization audit, the formula estimates the prevalence of disease (pretest probability [PTP]) in the patients tested. The comparison of PTPs among different providers, provider groups, or patient cohorts produces an objective evaluation of laboratory requests. We demonstrate the model in a review of tests for enterovirus (EV) meningitis.
  
  
  RESULTS
  The model identified subpopulations within the cohort with a low prevalence of disease. These low prevalence groups shared demographic and seasonal factors known to protect against EV meningitis. This suggests too many orders occurred from patients at low risk for EV.
  
  
  CONCLUSIONS
  We introduce a new method for laboratory utilization management programs to audit laboratory services.
authors.affiliation: Department of Laboratory Medicine, Yale University School of Medicine, New Haven, Connecticut, USA.
authors.forename: Ronald G
authors.initials: RG
authors.lastname: Hauser
authors.affiliation: Department of Pathology, University of Utah, Salt Lake City, Utah, USA ; ARUP Laboratories, Salt Lake City, Utah, USA.
authors.forename: Brian R
authors.initials: BR
authors.lastname: Jackson
authors.affiliation: Department of Laboratory Medicine, University of Washington, Seattle, Washington, USA.
authors.forename: Brian H
authors.initials: BH
authors.lastname: Shirts
keywords: Delivery of health care; efficiency; guideline adherence; health care; organization; physicians’ practice patterns; process assessment (health care); quality assurance; utilization review