Enhancing laboratory test consistency through linear transformation: A multi-center study

China is promoting the mutual recognition of clinical laboratory test results to reduce redundant testing, provide more convenient medical services, and lower economic burdens. This study aimed to enhance the consistency of test results across laboratories using a linear transformation method, focusing on five representative biochemical parameters: ALP, CA, TBIL, TC, and TG.

Five ISO 15189 accredited laboratories participated in this study. We established inter-laboratory and intra-laboratory conversion relationships using patient sample comparisons and daily quality control (QC) data. These relationships were used to develop a web-based tool enabling real-time conversion and mutual recognition of laboratory test results.

The study found that the linear transformation method effectively improved the consistency of test results. After three stages of conversion, most test results showed deviations within ±1/2 TEa when compared to a reference laboratory. However, some parameters in the low-value range exhibited less significant conversion effects, likely due to the sensitivity of percentage deviation measurements in this range.

The developed approach and web-based tool show potential for enhancing result consistency and facilitating mutual recognition across laboratories. Despite its effectiveness, the study's limitations, such as a small sample size and a narrow focus on five biochemical parameters, indicate the need for further research and broader application.