This is the protocol for a review and there is no abstract. The objectives are as follows:
We will assess the clinical effectiveness and safety of prolonged storage of PRBCs in comparison with fresh PRBCS for blood transfusion. We will only include PRBCs as they are the most frequently transfused blood product. We will consider prolonged storage as storage of 21 days or more. We have chosen this cut-off since it is the chronological midpoint in storage duration for additive solution units (42 days) (Bennett-Guerrero 2009).