Annelotte van Bommel

22 histological confirmed diagnosis. Information regarding diagnostic procedures, surgery, reconstructive surgery, radiotherapy, neo-adjuvant and adjuvant systemic treatment is collected. For case-mix adjustment, baseline characteristics of the patient (e.g., age, previous breast surgery) and tumor characteristics (e.g., histology, tumor stage, receptor status) are collected. Depending on the treatments given, a maximum of 75 items is registered per patient. Participating hospitals can either register the data themselves (facilitated by the web-based data-collection system of DICA) or have the data registered by IKNL- data-managers. Amanual is available to secure uniformdata acquisition. When data are registered by IKNL, hospitals can check the indicators and data on patient level for possible inconsistencies before the data are transferred to the DICA-system, in which data of all participating hospitals are gathered. Patient information is anonymized before transfer of the data to the national database. Hospitals registering the data themselves (through data-managers or specialized nurses) enter the data directly into the secured web-based systemof DICA. 5 A third trusted party de-identifies data directly after data entry. 6 Data are continuously collected. Entry and accuracy of data remain the responsibility of the participating hospitals. Benchmarking and transparency of quality indicator results Throughout the year, individual hospitals have continuous insight into their own performance on the quality indicators, alongwith other baseline information such as patient, tumor and treatment characteristics that are updatedweekly on their secured MyNBCA website. The quality indicators are nationally benchmarked against the other (anonymously presented) hospitals. Funnel plots are used to present indicator results in conjunction with the benchmark results. Annually, comprehensive reports with performance on all quality indicators of all institutions are disclosed to other parties, such as the national health care inspectorate and health care providers. In addition, an annual report with in depth research is available online for the public. Analyses Information of all patients who were operated for invasive breast cancer or DCIS between 1 January 2011 and 30 September 2014 was available for analysis. Results