Pilot study on laboratory sample exchange: Evaluation and key findings

Abstract Background External quality control is a critical component of laboratory medicine, ensuring the accuracy, reliability, and comparability of test results across different laboratories and over time. This study aimed to evaluate the feasability of implementing a split-sample pilot exchange program involving multiple laboratories in Romania. Methods The program involved six rounds of a split-sample protocol between 34 public and private Romanian laboratories, including four basic chemistry parameters: glucose, total cholesterol, triglycerides, and HDL-cholesterol. Performance was evaluated with traditional assessment methods, including Z-scores and performance specifications derived from biological variation. Results were analyzed to determine compliance with acceptable limits and performance metrics. Results Overall, most laboratories achieved satisfactory results when assessed using mean ±3 standard deviations, particularly for total cholesterol and triglycerides. However, a significant number of laboratories failed to meet optimal Total Allowable Error (TAE) limits for glucose and HDL-cholesterol. While glucose showed satisfactory minimum TAE performance, many laboratories reported values above clinical decision thresholds. Similar trends were observed for HDL-cholesterol, where a notable proportion of laboratories did not meet optimal TAE specifications. These findings suggest that relying solely on Z-scores may be inadequate for performance evaluation. Conclusions More stringent performance criteria are warranted to identify areas for improvement, ensuring consistent and reliable laboratory results that can accurately inform clinical decisions across participating laboratories. This could facilitate better identification of corrective actions.