title: Observation interval for evaluating the costs of surgical interventions for older women with a new diagnosis of breast cancer.
abstract: OBJECTIVE
  To estimate the episodic costs of surgical treatments for breast cancer.
  
  
  METHODS
  The surgical treatment period as the 6 weeks following diagnosis is defined. Using a sample of 205 women aged 65 and older and their Medicare claim files, the cost of treatment is estimated and the progression from first to subsequent surgical procedures during the 6-week interval is demonstrated with a decision tree. Two equations are then estimated: the probability of mastectomy versus breast conserving surgery (BCS) as first surgery using Probit regression and the log of total charges using a generalized linear regression model.
  
  
  RESULTS
  It was found that only stage predicts the probability of mastectomy versus BCS and that 54% of women receiving BCS undergo a second surgery. Once all treatments in the initial surgical period are accounted, the difference between the adjusted cost of mastectomy alone and BCS followed by a second surgery was not statistically significant. Only a successful first BCS is statistically significantly (P <0.05) less costly than a mastectomy alone ($4,955 vs. $9,049).
  
  
  CONCLUSIONS
  By defining a 6-week surgical treatment episode it is shown that BCS followed by subsequent surgeries is the more costly option for initial treatment. Given the high prevalence of second surgeries, previous work may have underestimated the costs of surgical interventions for breast cancer.
authors.affiliation: Department of Family Practice, Michigan State University, East Lansing 48824, USA. givenc@msu.edu
authors.forename: C
authors.initials: C
authors.lastname: Given
authors.forename: C
authors.initials: C
authors.lastname: Bradley
authors.forename: A
authors.initials: A
authors.lastname: Luca
authors.forename: B
authors.initials: B
authors.lastname: Given
authors.forename: J R
authors.initials: JR
authors.lastname: Osuch
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001943:Breast Neoplasms / Q000601:surgery*; D003362:Cost-Benefit Analysis; D003663:Decision Trees; D017050:Episode of Care; D005260:Female; D017048:Health Care Costs; D017722:Hospital Charges; D006801:Humans; D016013:Likelihood Functions; D015409:Mastectomy, Radical / Q000191:economics* / Q000706:statistics & numerical data; D015412:Mastectomy, Segmental / Q000191:economics* / Q000706:statistics & numerical data; D006278:Medicare; D012044:Regression Analysis; D012086:Reoperation / Q000191:economics / Q000706:statistics & numerical data; D014481:United States