[1] Univ Med Ctr Goettingen, Dept Clin Chem, D-37075 Gottingen, Germany
[2] Abbott Labs, Abbott Pk, IL 60064 USA
[3] Dept Clin Pharmacol, Brisbane, Qld, Australia
[4] Univ Queensland, Princess Alexandra Hosp, Brisbane, Qld, Australia
[5] Roche Diagnost Ltd, Rotkreuz, Switzerland
[6] Catholic Univ Louvain, Dept Clin Chem, Clin Univ St Luc, LTAP, B-1200 Brussels, Belgium