title: A method to compare costs of drugs and supplies among anesthesia providers: a simple statistical method to reduce variations in cost due to variations in casemix.
abstract: BACKGROUND
  Comparison of costs among anesthesia providers using "cost per case" does not adjust for variations in casemix (such as the type of procedure and patient condition). The authors propose an alternative method for comparing costs using the American Society of Anesthesiologists' Relative Value Scale (ASARVS) system, which incorporates basic units (for the procedure), modifier units (for the patient's physical condition), "other" units (such as for the placement of invasive monitors), and time units (proportional to the case duration).
  
  
  METHODS
  Data were obtained from a series of 3,340 anesthetics performed at a tertiary hospital. Administered and discarded drug, supply, and fluid costs were used.
  
  
  RESULTS
  Costs expressed as dollars per ASARVS unit had 54% less variability than costs expressed as dollars per case (P < 0.0001). Pearson correlations between demographic variables and cost per ASARVS unit ranged from -0.10 to 0.13. Total (e.g., quarterly) costs for simulated sets of cases were predicted within 0.0 +/- 2.3% by multiplying (1) their sum of units and (2) a like set of case's sum of costs divided by sum of units.
  
  
  CONCLUSIONS
  Costs of anesthetic supplies and drugs of a case were more accurately reported as "cost per unit" than as "cost per case." This method of calculating the cost of anesthetic drugs and supplies has several applications, including (1) comparison of costs among anesthesia providers and (2) benchmarking costs among hospitals and anesthesia groups. By design, anesthesia providers' time is quantified by their ASARVS units. Together anesthesia costs (personnel, supplies, and drugs) are better reported as "cost per unit" than as "cost per case."
authors.affiliation: Department of Anesthesia, University of Iowa, Iowa City 52242, USA. franklin-dexter@uiowa.edu
authors.forename: F
authors.initials: F
authors.lastname: Dexter
authors.forename: D A
authors.initials: DA
authors.lastname: Lubarsky
authors.forename: B C
authors.initials: BC
authors.lastname: Gilbert
authors.forename: C
authors.initials: C
authors.lastname: Thompson
mesh_terms: D000328:Adult; D000758:Anesthesia / Q000191:economics*; D003365:Costs and Cost Analysis / Q000379:methods*; D016208:Databases, Factual; D003953:Diagnosis-Related Groups; D004209:Disposable Equipment / Q000191:economics*; D016527:Drug Costs / Q000706:statistics & numerical data*; D006801:Humans; D008875:Middle Aged