Table 1 Definition of appropriateness assessment

With Lab Test / Appropriate:

• Pre-transfusion Hb concentration < 7 g/dl;

• Pre-transfusion Hb concentration 7–8 g/dl, and preoperative chronic anemia;

• Pre-transfusion Hb concentration 7–10 g/dl, and age ≥ 65 years or ASA grade in III-V or blood loss ≥1000 ml;

• Pre-transfusion Hb concentration 7–10 g/dl, and renal failure or history of cardiovascular disease, hematencephalon, lungs injury or undergone neurosurgical operations, orthopedic operations or cardiovascular operations;

With Lab Test / Inappropriate:

• Pre-transfusion Hb concentration 7–10 g/dl, without above mentioned comorbidities, or pre-transfusion Hb concentration > 10 g/dl.

Without Lab Test: /Inappropriate

Lack of Hb and other testing records before and after allogeneic RBC transfusion.