Observation Interval for Evaluating the Costs of Surgical Interventions for Older Women with a New Diagnosis of Breast Cancer

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