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 i s defined. Using a sample of 205 women aged 63 and older and their Medicare claim files, the cost of treatment is estimated and the progression from f irst to subsequent surgical procedures during the 6-week interval is demons trated with a decision tree. Two equations are then estimated: the probabil ity of mastectomy versus breast conserving surgery (BCS) as first surgery u sing Probit regression and the log of total charges using a generalized lin ear regression model. RESULTS. It was found that only stage predicts the probability of mastectom y versus BCS and that 54% of women receiving BCS undergo a second surgery. Once all treatments in the initial surgical period are accounted, the diffe rence between the adjusted cost of mastectomy alone and BCS followed by a s econd surgery was not statistically significant. Only a successful first BC S is statistically significantly (P < 0.05) less costly than a mastectomy a lone ($4,935 vs. $9,049). CONCLUSIONS. By defining a 6-week surgical treatment episode it is shown th at BCS followed by subsequent surgeries is the more costly option for initi al treatment. Given the high prevalence of second surgeries, previous work may have underestimated the costs of surgical interventions for breast canc er.