A New Biometrical Procedure for Testing the Equality of Measurements from Two Different Analytical Methods. Application of linear regression procedures for method comparison studies in Clinical Chemistry, Part I

Abstract

Procedures for the statistical evaluation of method comparisons and instrument tests often have a requirement for distributional properties of the experimental data, but this requirement is frequently not met. A new linear regression procedure with no special assumptions regarding the distribution of the samples and the measurement errors is proposed. The result does not depend on the assignment of the methods (instruments) to X and Y. After testing a linear relationship between X and Y confidence limits are given for the slope .beta. and the intercept .alpha.; they are used to determine whether there is only a chance difference between .beta. and 1 and between .alpha. and 0. The mathematical background is amplified separately in an appendix.