[1] Belgian Red Cross Flanders, Transfus Res Ctr, Mechelen, Belgium
[2] Leuven Inst Healthcare Policy, Ctr Evidence Based Hlth Care, Dept Publ Hlth & Primary Care, Leuven, Belgium
[3] Stellenbosch Univ, Fac Med & Hlth Sci, Ctr Evidence Based Hlth Care, Cape Town, South Africa
[4] Belgian Red Cross Flanders, Pillar Res Ctr 3, Motstr 42, B-2800 Mechelen, Belgium