Annelotte van Bommel

11 as well as guidelines to optimize institutional infrastructures. In 2011, NABON, the Dutch Institute for Clinical Auditing (DICA) 6 and the Comprehensive Cancer Organization the Netherlands (IKNL) 7 joined forces and initiated the NABONBreast Cancer Audit (NBCA). 8 Representatives of all medical specialties involved in breast cancer care defined a number of multidisciplinary quality indicators to measure different aspects of breast cancer care. These indicators reflected adherence to existing diagnostic work-up and treatment guidelines. Full participation of all Dutch hospitals in the Netherlands was realized within a few years. The primary goal of the NBCA is to monitor the quality of provided breast cancer care in hospitals in the Netherlands by offering participating individual hospitals feedback on their results in relation to “real-time” national benchmark information with case-mix adjustment if needed. The second objective, comparison of hospital performances using quality indicators, is a more complex endeavor weighing multiple factors, and interpreting the results should be done with caution. First, defining unambiguous quality indicators reflecting the quality of breast cancer treatment is not as easy as it seems and is still an ongoing process. Second, case- mix adjustment can only compensate for variation in outcomes as long as the involved confounding factors are identified. Moreover, even following case-mix adjustment, interpreting the remaining hospital variation has to be done with certain caution. Exploring observed variation on a national level serves as the “Check” step, and may result in the adjustment of guidelines as an “Act” to close the PDCA cycle. In the present form of the NBCA, (reconstructive) surgical items are well covered. Breast conserving surgery has been performed in the majority of patients diagnosed with breast cancer during the last 40 years and consequently has been the cornerstone of surgical breast cancer care. Combining mastectomy with an immediate breast reconstruction was introduced more recently and its increasing use on a national level demonstrates the increased awareness of the importance of esthetic outcomes after breast cancer surgery. Zooming in on an institutional level, variation in collaboration between surgical oncologists and plastic surgeons as well as in hospital organizational factors may result in substantial variation in the 1 Introduction