An analysis of the Washington Conference Report on bioanalytical method validation

The Washington Conference Report on bioanalytical method validation is analysed with respect to the requirements for precision and accuracy. It is shown that if the requirements are interpreted too literally, this could lead to disappointment in practice. A better approach is to separate the total measurement error into its constant (bias) and random (precision) components. To ensure that 95% of all methods fall within the acceptance interval of +/- 15% around the true value, would require, for example, the bias to be < or = 8% and the method precision to be < or = 8% relative standard deviation (RSD; n = 5).