Publication: Commutability assessment of human urine certified reference materials for albumin and creatinine on multiple clinical analyzers using different statistical models

 I first heard about "communtability" from Russ Grant (Labcorp) at either a CPSA or AAPS Crystal City conference during discussions of biomarkers.  The discussion furthered my enlightenment on the practices in clinical laboratories that support medical practice. These practices, while in some cases similar to the FDA Bioanalytical Method Validation guidance, are different; as would be expected for the differences in intended use of the data. John Allinson (Immunologix Laboratories), Steve Piccoli (SPARC) and Erica Troksa (Labcorp) subsequently challenged my notions on the application of BMV to biomarkers measured in clinical laboratories and helped me realize that clinical laboratory practices are many times superior to bioanalytical labs when it comes to measuring biomarkers; especially when considering the intended use of the data.

In this case, the authors of the article explore albumin and creatinine reference materials tested across several clinical analyzers to assess the comparability/comparability of the devices and their assays for these analytes (measurands) in urine.  There are numerous publications that discuss the challenges in achieving comparable (note not equivalent) results across clinical laboratories. This article explores one lab-based approach and 2 statistical approaches to demonstrate that the data from the different instruments and assays are similar enough to result in a common outcome (i.e., medical determination):

Abstract

Urine albumin concentration and albumin–creatinine ratio are important for the screening of early-stage kidney damage. Commutable urine certified reference materials (CRMs) for albumin and creatinine are necessary for standardization of urine albumin and accurate measurement of albumin–urine ratio. Two urine CRMs for albumin and creatinine with certified values determined using higher-order reference measurement procedures were evaluated for their commutability on five brands/models of clinical analyzers where different reagent kits were used, including Roche Cobas c702, Roche Cobas c311, Siemens Atellica CH, Beckman Coulter AU5800, and Abbott Architect c16000. The commutability study was conducted by measuring at least 26 authentic patient urine samples and the human urine CRMs using both reference measurement procedures and the routine methods. Both the linear regression model suggested by the Clinical and Laboratory Standard Institute (CLSI) guidelines and log-transformed model recommended by the International Federation of Clinical Chemistry and Laboratory Medicine (IFCC) Commutability Working Group were used to evaluate the commutability of the human urine CRMs. The commutability of the human urine CRMs was found to be generally satisfactory on all five clinical analyzers for both albumin and creatinine, suggesting that they are suitable to be used routinely by clinical laboratories as quality control or for method validation of urine albumin and creatinine measurements. [Analytical and Bioanalytical Chemistry volume 415, pages 787–800 (2023)]