Our study of transfusion practice reflected the "real world" management by surgeons of patients with total hip joint arthroplasty. This approach is more relevant than the alternative, suggested by Dr. Kontor, of imposing arbitrary, non–evidence-based strict transfusion criteria. Most participants (64%) in the second Canadian Orthopedic Perioperative Erythropoietin Study (COPES II) who received transfusion had a hemoglobin concentration less than 80 g/L. Most clinicians accept that treatment or prevention of this degree of anemia in elderly patients undergoing total hip joint arthroplasty is desirable.

While we acknowledge that little evidence exists to support the notion that transfusion improves mortality rates in patients with a hemoglobin concentration between 80 and 100 g/L, we disagree with the assertion that patients who either avoided transfusion or received allogeneic blood did not benefit.

Although Carson and colleagues (1) failed to show a positive effect of blood transfusion on mortality rate in patients with a hip fracture whose hemoglobin concentration was greater than 80 g/L, the authors stressed that their observational study may have been influenced by confounders and lacked the statistical power to exclude a 25% mortality reduction. More important, the potential benefits of transfusion on functional status, a vital issue for patients with total hip joint arthroplasty, were not evaluated. The authors concluded that evidence from a controlled trial is necessary to determine whether transfusion is beneficial in these patients.

Dr. Kontor also quotes another retrospective study, by Zuccalà and coworkers (2), which suggested that transfusion in patients with hip fracture was associated with a sixfold increase in mortality rate. However, the average age of participants was 80 years and 21% of patients who received a transfusion died. No patients in COPES II died. Since it is obvious that the two samples are substantially different, the comparison of these studies is not meaningful. Similarly, the study by Hébert and associates (3) was performed in a group of critically ill patients who were dissimilar to patients with total hip joint arthroplasty. Again, no measures of functional status were obtained. Taken collectively, these studies underscore the need for further data from controlled trials to establish the optimum postoperative hemoglobin concentration in patients with total hip joint arthroplasty. Such studies should evaluate the effects of anemia on mortality and measures of functional status.