Six Sigma in Action: Evaluating Its Practicality in a Multi-Analyzer Laboratory under CLIA 2024 Guidelines.

OBJECTIVE

The stricter Clinical Laboratory Improvement Amendments (CLIA) 2024 guidelines introduced narrower Total Allowable Error (TEa) limits, posing challenges for clinical laboratories in maintaining analytical quality. This study evaluated the effectiveness of Six Sigma metrics in assessing the performance of routine biochemical tests using these updated criteria.

METHODS

This retrospective study analyzed the internal quality control (IQC) data for 22 biochemical analytes across four instruments in a high-throughput laboratory. Performance was assessed using Sigma metrics calculated based on the CLIA 88 and CLIA 2024 criteria, with classifications into poor (<3 Sigma), acceptable (3-6 Sigma), and excellent (>6 Sigma) categories. İnstrument-specific variability and control levels (normal and pathological) were also analyzed.

RESULTS

Under the CLIA 2024 guidelines, only 22.16% of the analytes achieved excellent performance (>6 Sigma), compared to 49.43% under CLIA 88. No significant differences were observed between instruments, indicating consistent analytical performance across platforms. Normal control levels (Control Level 1) exhibited greater variability (median Sigma: 4.76, range: 1.19-13.34) compared to pathological controls (Control Level 2) (median Sigma: 4.72, range: 1.22-10.22), reinforcing the impact of control level differences on analytical precision. CRP, CK, and Bilirubin were the highest-performing tests, consistently maintaining high Sigma values above the acceptable threshold. In contrast, Albumin, Urea, and GGT exhibited the lowest Sigma performance.

CONCLUSIONS

The transition to stricter CLIA 2024 guidelines significantly affects the analytical performance of biochemical tests, highlighting vulnerabilities in routine laboratory operations. Adopting advanced automation, tailored QC protocols, and modern analytical tools is essential to enhance diagnostic precision and ensure compliance with evolving regulatory demands.