Comparing Apples with Oranges
A. M. Beliaev, R. J. Marshall, et al. (2011). ‘Clinical benefits and cost-effectiveness of allogeneic red-blood-cell transfusion in severe symptomatic anaemia.’ Vox Sang.
J. P. Isbister
Sydney Medical School, Royal North Shore Hospital of Sydney, Sydney, NSW, Australia
Dear Editor,
The article by Beliaev et al. has flaws in the interpretation of their data and should not go unchallenged. On the basis of the data presented, it is not possible to conclude that red cell transfusions were causally related to better clinical and economic outcomes in anaemic patients.
The Jehovah’s Witness (JW) ‘control’ and ‘intervention’ groups differ in age, ethnicity, diabetes, bronchiectasis ⁄tuberculosis and renal disease. The JW patients may alsohave received an otherwise suboptimal standard of carebecause they would not receive blood transfusions. Toconclude from this study that red cell transfusion in anaemicpatients reduces mortality, gastrointestinal bleeding,infection rates, cardiac arrhythmias, angina, ischaemicmyocardial injury, renal failure, neurological complications, delirium, depression and syncopal episodes challenges credibility, experience and currently availableevidence. The efficacy of transfusion may well be the case in critically bleeding, shocked and vascular diseased patients.
Indigenous populations have worse clinical outcomes than the general population, and the younger age of the JWs possibly reflects this fact. It is difficult accepting that the JW group can be regarded as ‘controls’ for anaemia, and the authors’ definition of severe anaemia is also problematic. Although there is evidence from the literature confirming that increasing anaemia correlates with poorer clinical outcomes, red cell transfusion does not necessarily correct the problem, unless the anaemia is critical and ⁄ or the patient is actively bleeding. The haemoglobin nadir of the transfusion group was 80 ± 13 g ⁄ l and received 3 Æ 3 ± 3 units of allogeneic red cell concentrates.
This would suggest that many of the patients in the intervention group were transfused when their haemoglobin levels were above the triggers for the study and over transfused. The current extensive reassessment of the indications for red cell transfusion, especially in anaemic haemodynamically stable patients, is challenging the long held dogma that transfusion can only be good for patients [1]. RCTs confirm the safety of restrictive transfusion policies [2], and the recent International Consensus Conference on Transfusion Outcomes concluded that there are limited indications for transfusion in haemodynamically stable anaemic patients and there is a high degree of uncertainty as to which patients may benefit from red cell transfusions [3]. There is also evidence relating to perioperative JW patients having similar or better clinical outcomes without blood transfusion [4]. Additionally, the large RCT in elderly high-risk patients undergoing hip arthroplasty found no benefit from transfusion in asymptomatic patients with Hb > 80 g ⁄ l [5].
Cost-effectiveness conclusions are invalid if efficacy of an intervention has not been established and there is no overall real activity–based costing. Realistically, the authors can only conclude that a heterogeneous population of anaemic patients who happen to be JWs are more costly to manage than a heterogeneous population of anaemic patients accepting transfusion, who happen not to be JWs.
References
1 Shander A, Javidroozi M, Ozawa S, et al. : What is really dangerous:
anaemia or transfusion? Br J Anaesth 2011; 107(Suppl 1):
i41–i59
2 Hebert PC, Wells G, Blajchman MA, et al. : A multicenter, randomized,
controlled clinical trial of transfusion requirements in
critical care. Transfusion Requirements in Critical Care Investigators,
Canadian Critical Care Trials Group. N Engl J Med 1999;
340(6):409–417
3 Shander A, Fink A, Javidroozi M, et al. : Appropriateness of
allogeneic red blood cell transfusion: the international consensus
conference on transfusion outcomes. Transfus Med
Rev 2011; 25(3):232–246
4 Reyes G, Nuche JM, Sarraj A, et al. : Bloodless Cardiac Surgery in
Jehovah’s Witnesses: Outcomes Compared With a Control Group.
Rev Esp Cardiol 2007; 60(7):727–731 e53
5 Carson JL, Terrin ML, Noveck H, et al. : Liberal or restrictive
transfusion in high-risk patients after hip surgery. N Engl J
Med 2011; 365(26):2453–2462
Received: 27 January 2012,
accepted 28 February 2012
