[Variability and opportunity costs among the surgical alternatives for breast cancer]

To analyze medical practice variation in breast cancer surgery (either inpatient-based or day-case surgery), by comparing conservative surgery (CS) plus radiotherapy vs. non-conservative surgery (NCS). We also analyzed the opportunity costs associated with CS and NCS.

We performed an observational study of age- and sex-standardized rates of CS and NCS, performed in 199 Spanish healthcare areas in 2008-2009. Costs were calculated by using two techniques: indirectly, by using All-Patients Diagnosis Related Groups (AP-DRG) based on hospital admissions, and directly by using full costing from the Spanish Network of Hospital Costs (SNHC) data.

Standardized surgery rates for CS and NCS were 6.84 and 4.35 per 10,000 women, with variation across areas ranging from 2.95 to 3.11 per 10,000 inhabitants. In 2009, 9% of CS was performed as day-case surgery, although a third of the health care areas did not perform this type of surgery. Taking the SNHC as a reference, the cost of CS was estimated at 7,078 € and that of NCS was 6,161 €. Using AP-DRG, costs amounted to 9,036 € and 8,526 €, respectively. However, CS had lower opportunity costs than NCS when day-case surgery was performed frequently-more than 46% of cases (following SNHC estimates) or 23% of cases (following AP-DRG estimates).

Day-case CS for breast cancer was found to be the best option in terms of opportunity-costs beyond a specific threshold, when both CS and NCS are elective.