The very simple answer is: Medical Literature continues to show patients who recieve blood product transfusions are more likely to have prolonged hospital stays, longer surgeries, more bleeding and a higher risk of infection, stroke and death.

Studies are yet to prove the contrary.

I was a patient at the Houston Veterans hospital and had a total knee replacement on my right knee. As a JW I did not have a blood transfusion, but the doctors used "meticulous hemostasis". The vacumn container used to hold excessive blood loss had maybe, just maybe, one or two drops of pinkish fluid in it. I was up and walking the next day, and when the PT tech checked my walking and mobility, I passed with the reccomendation that I did not need any further PT. On the fourth day, I went home. On the tenth day, I went back to have my sutures removed, the doctor told me that the other seven vets that had knee replacements the day that I did were still in the hospital with various degres of complications. Note that it is part of the TKR surgery to transfuse one or two pints of blood during the surgery. Very interesting, is it not?