Standardized evaluation of regional and institutional breast cancer outcomes

Background Optimal breast cancer control outcomes include early diagnosis, thorough staging work-up, and lowest disease-related mortality. Methods The standardized case-mix index (SCI) for breast cancer was derived from the stage distribution of cases weighted for earlier diagnosis using the national stage 5-year mortality provided in the National Cancer Data Base expressed as an institution or region (observed) to national (expected) ratio (O/E). The standardized work-up index was the mean O/E mortality ratio for each stage. The standardized treatment index was the total O/E 5-year mortality corrected for the SCI. The overall performance evaluation (OPE) was SCI × standardized work-up index × standardized treatment index. Institutional data were acquired from a prospectively maintained breast cancer database. Results OPE scores for 42 states acquired from the National Cancer Data Base tended to be best for the northeast and northwest states. Washington and Oregon OPE scores were in the top 20%. The Swedish Cancer Institute OPE score improved steadily from 1990 to 2000 and was better than the Washington state score. Conclusions By calibrating breast cancer stage of diagnosis and mortality to a national standard, regional and institutional breast cancer control programs can be compared objectively.