Annelotte van Bommel

93 Organizational factors affect the use of immediate breast reconstruction et al. demonstrated that IBR rates were most probably higher in specialized cancer centers, because of high referrals to plastic surgeons. 19 Others revealed that high volume clinical breast hospitals extensively collaborate with plastic surgery departments, which could result in higher IBR rates. 13,19 We were not able to demonstrate a significant association between a higher volume hospital (>150 diagnoses) and higher IBR rates for invasive breast cancer. In our study a higher number of plastic surgeons working in a hospital positively affected IBR rates. However, the number of breast surgeons working in a hospital did not. Breast surgeons in the Netherlands differ from the breast surgeons in other countries, since Dutch oncologic breast surgeons only perform breast ablative surgery or breast conserving surgery and do not carry out breast reconstructions, which is exclusively performed by plastic surgeons. In addition, the presence of a plastic surgeon at the MDT meeting positively affected the use of IBR. Alderman et al. demonstrated that a large proportion of surgeons did not refer breast cancer patients to a plastic surgeon at the time of surgical decision- making. 19 This implicates the relevance of the attendance of a plastic surgeon at the weekly MDTmeeting to timely discuss the possibility of IBR. However, in Dutch clinical practice, it is quite common for patients to visit the plastic surgeon before surgery. Interestingly, Alderman et al. also concluded that surgeons who have a high referral propensity are more likely to be women. 19 Unfortunately we did not have information on gender of the (plastic) surgeon. Limitations In total, 72 of the 92 of the Dutch hospitals (78.3%) participated in this study, despite repeated invitations to the non-responding hospitals. However, the included hospitals are a good reflection of all Dutch hospitals, since representative proportions of hospital type and hospital volume were included. Although we were able to demonstrate a significant effect of hospital type on IBR rates, it is important to realize that even within three out of four hospital categories variation in performing IBR existed. DCIS and invasive breast cancer were analyzed separately, to make testing for confounding (tumor factors such as tumor and nodal stage) possible. However, 5