Inclusion Criteria:  age ≥ 18 years male and female patients patients eligible for inclusion: by the patient, preoperatively patients who are insured with BARMER or other statutory health insurances patients with preoperative anemia and an elective (N5) surgical intervention with a probability of transfusion > 10%  additionally for the use of MAT:  indication of machine autotransfusion high blood loss (> 500ml / 10-20 % of estimated blood volume) beside of indication interventions (surgery under dual platelet inhibition, high individual bleeding risk, special antibodies / rare blood group, rejection of allogeneic blood)  Exclusion Criteria:  patients with emergency interventions rejection of study participation pregnancy, elective caesarean section or breastfeeding not enough German language skills accommodation in an institution because of judicial or administrative order employee of Charité missing of declaration of consent