Annelotte van Bommel

160 SUPPLEMENTARY TABLE Characteristics of respondents (n=558) versus non-respondents (n=660) to the questionnaire about quality of life after mastectomy or immediate breast reconstruction. Respondents Non-respondents Total P-value n=558 % n=660 % n=1218 Age at time of mastectomy Mean 54.59 54.43 <50 182 33% 245 37% 427 50 - 65 246 44% 208 32% 454 65 or above 130 23% 207 31% 337 <0.001 Type of cancer Invasive breast cancer 434 78% 497 75% 931 DCIS 124 22% 163 25% 287 0.311 Year of surgery 2013 313 56% 391 59% 704 2014 245 44% 269 41% 514 0.268 Breast reconstruction Immediate breast reconstruction 253 45% 248 38% 501 No reconstruction / delayed breast reconstruction* 305 55% 412 62% 717 0.006 Volume of hospital** High 316 57% 332 50% 648 Middle 193 35% 259 39% 452 Low 49 9% 69 10% 118 0.086 DCIS: ductal carcinoma in situ * Delayed breast reconstruction (25 patients) are excluded from future analyses. ** Volume calculated by number of mastectomies: number of surgical treated breast cancer patients per year (average over 2012-2014), categorized as low (<150), middle (150e249), and high (>250) volume.