title: Severity adjustment for length of stay: is it always necessary?
abstract: OBJECTIVE
  Severity adjustment is an oft-cited requirement when comparing physicians or medical delivery systems. Each application of severity adjustment, however, has to be tested to validate the need, the method, and its value. We examined the value of severity adjustment for identifying physician outliers when studying length of stay in the hospital.
  
  
  METHODS
  We compared the placement of physicians in an outlier category using a severity-adjusted average length of stay (SLOS) index with their placement using the unadjusted average length of stay (ALOS). Changes in placement of the list were validated by the utilization review coordinators.
  
  
  METHODS
  A 614-bed tertiary-care university teaching hospital.
  
  
  METHODS
  We analyzed 11,146 discharges from 138 physicians in 1992.
  
  
  RESULTS
  The mean ALOS +/- standard deviation was 9.05 + 4.50 days, and the SLOS Index was 7.56 +/- 3.06. There were 120 inliers, 6 high outliers, and 12 low outliers by the ALOS method. Using the SLOS index, 27 of 138 physicians had their categories changed from inlier to outlier or from outlier to inlier. The difference in group changes was more significant for those going from outlier to inlier status (8/120 vs 6/18; P < .001). The patients of the six physicians whose status changed from outlier to inlier status were sicker, as indicated by the comorbidity, complications, and manifestations of disease processes score. The utilization reviewers validated the status changes in 8 of 14 instances.
  
  
  CONCLUSIONS
  Severity-adjusted length of stay by the SLOS index appears to provide a more accurate measure than the unadjusted ALOS. The changes, however, were small. It is not clear that the added effort is worthwhile.
authors.affiliation: Hackensack University Medical Center, NJ 07601, USA.
authors.forename: P A
authors.initials: PA
authors.lastname: Gross
authors.forename: P
authors.initials: P
authors.lastname: Cataruozolo
authors.forename: P
authors.initials: P
authors.lastname: DeMauro
authors.forename: P
authors.initials: P
authors.lastname: Eason
authors.forename: M
authors.initials: M
authors.lastname: Elliot
authors.forename: S
authors.initials: S
authors.lastname: Wallenstein
mesh_terms: D006746:Hospital Bed Capacity, 500 and over; D006785:Hospitals, University / Q000458:organization & administration / Q000706:statistics & numerical data*; D006801:Humans; D007902:Length of Stay; D009515:New Jersey; D016311:Outliers, DRG; D010351:Patient Discharge / Q000706:statistics & numerical data; D010818:Practice Patterns, Physicians' / Q000706:statistics & numerical data; D012720:Severity of Illness Index; D014600:Utilization Review / Q000379:methods