title: Factors that affect surgical rates in Iowa.
abstract: METHODS
  This study analyzed insurance claims to estimate the probability of medical and surgical treatments in different Iowa communities. The likelihood of surgical treatment was associated with patient characteristics of age and gender as well as hospital characteristics of size (number of beds), occupancy rate, and number of staff.
  
  
  OBJECTIVE
  Our findings are being used by a study group of 25 physicians to understand the causes of variation in surgical rates for low back pain. Medical education and other interventions are being implemented.
  
  
  BACKGROUND
  Hospitalization rates for lower back operations in the United States increased by more than 20% from 1978 to 1985. Consequently, several studies in Iowa and the US have been initiated to examine the medical effectiveness of these treatments.
  
  
  METHODS
  A logistic regression model was used to determine the factors associated with the likelihood of having a low back surgery in a population of Blue Cross/Blue Shield (BCBS) subscribers in Iowa. The outcome, or dependent variable, of interest was a hospitalization that resulted in a surgical procedure on a low back pain patient.
  
  
  RESULTS
  Surgical rates for the treatment of low back pain are likely to be increased if a BCBS Iowa subscriber is female, older than 44 years of age, or if the surgery is performed in a hospital with either an occupancy rate less than 62%, with fewer than 774 staff members, fewer than 267 beds, or no residency programs.
authors: Faculty of Medicine, Harvard University, Cambridge, Massachussetts.
authors: S M
authors: SM
authors: McGuire
authors: K T
authors: KT
authors: Phillips
authors: J N
authors: JN
authors: Weinstein
mesh_terms: D000328:Adult; D054598:Blue Cross Blue Shield Insurance Plans / Q000706:statistics & numerical data; D017586:Diskectomy / Q000706:statistics & numerical data*; D005260:Female; D006760:Hospitalization / Q000706:statistics & numerical data; D006801:Humans; D007345:Insurance Claim Review / Q000706:statistics & numerical data; D007484:Iowa / Q000453:epidemiology; D007796:Laminectomy / Q000706:statistics & numerical data*; D016015:Logistic Models; D017116:Low Back Pain / Q000453:epidemiology / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D013123:Spinal Fusion / Q000706:statistics & numerical data*