Annelotte van Bommel

120 Considering the positive effects of both IBR and SDM (for instance about treatment decisions) on the quality of life 7,22–24 , psychosocial functioning 25–28 , and patient satisfaction 29-31 of mastectomy patients, breast reconstruction should ideally be performed whenever feasible 22 and more importantly, pre-operatively discussed with patients in a process of SDM. Therefore, the objective of the present study was to investigate the underlying decision-making processes patients experienced during the preoperative consultations for their breast cancer surgery with or without IBR in the Netherlands. The second aim was to determine the effect of being informed about IBR on actually receiving IBR. METHODS Study population Twenty-nine hospitals (1/3rd of the total number of hospitals in the Netherlands) volunteered to participate in the study. These hospitals were general (n=15), teaching (n=10), academic hospitals (n=4, including a cancer-specific hospital), and all offered IBR in-house or referring to IBR-performing hospitals based on the national guideline asmentioned in the introduction. All patients that fit the inclusion criteria (female, aged 18 years, diagnosed with DCIS or invasive breast cancer, treated with mastectomy between January 2013 and October 2014, no distant metastases) were selected from the Netherlands Cancer Registry (NCR), a national registry in which all newly diagnosed cancer patients are registered annually. Based on our power calculation ( Supplementary Appendix 1 ), fifty patients (25 with IBR and 25 without IBR) were randomly selected from every participating hospital by assigning them a random value between 0 and 1 and including those with the lowest values. In consultation with each hospital, we then excluded patients with recent recurrent disease (we did not want to bother patients currently receiving treatment) and patients who were unfit to fill in a questionnaire (due to psychological difficulties (dementia, depression) or language limitations). Since information about DBR is not collected in the NCR, we could not exclude patients with DBR on beforehand. The survey was hosted in PROFILES (“Patient-Reported Outcomes Following Initial treatment and Long-termEvaluation of Survivorship”), an online secured environment which facilitates data collection on patient-reported