Local regression: a new approach for measurement system comparison analysis.

A new graphical approach for analysis of measurement system comparison studies is proposed. Unlike the established linear regression and Bland-Altman analysis, it does not depend on the assumption of a linear relationship. We review the established analysis approaches and propose a difference plot with non-parametric regression as an adequate tool to describe the relationship between two measurement systems.

Statistical methods for monitoring the relationship between the IFCC reference measurement procedure for hemoglobin A1c and the designated comparison methods in the United States, Japan, and Sweden.

Background: The American Diabetes Association (ADA)/European Association for the Study of Diabetes (EASD)/International Diabetes Federation (IDF)/IFCC Consensus Statement on the worldwide standardization of HbA(1c) states that "...

Uncertainty calculation for calibrators and controls of laboratory diagnostic assays.

The uncertainty of the results from calibrators and controls is an important component of the overall uncertainty of the results of medical samples. The purpose of this note is to review procedures of standardization and to describe the respective calculation of the uncertainty components for calibrators and controls of commercial routine diagnostic assays. The authors hope that the laying out of the procedures for uncertainty calculation of routine calibrators and controls contributes (i) to the transparency on how this component of uncertainty is derived and (ii) to a better understanding and use of the uncertainty concept in the routine laboratory.