English
The Clinical Laboratory Improvement Act (CLIA) updates for 2024 are adding several new assays and tightening goals of several others by up to 40%. Understanding proficiency testing of current assays will help to identify which assays and instruments will pass the new guidelines and which will not.
In this study, Westgard QC independently assessed the performance of 13 assays on the DxI 9000 Immunoassay Analyzer* (Table 1). Imprecision and bias were calculated following CLSI and EP09 guidelines, respectively, and the sigma metric was calculated for each. Results were compared with those from competitor assays and analyzers.
Table 1. Assay analyzed in an independent Westgard QC study
| Beta hCG | Cortisol | Creatine Kinase MB (CK-MB) | Estradiol |
| Folate | Para-thyroid hormone (PTH) | Total Prostate specific antigen (Total PSA) | Testosterone |
| Troponin I | Thyroid Stimulating Hormone (TSH) | Total Triiodothyronine (TT3) | Free Thyroxine (FT4) |
| Vitamin B12 | |||
The study found:
- The DxI 9000 Aalyzer assays “leads the diagnostic landscape” for six sigma performance under the new CLIA proficiency testing rules against competitive immunoassay analyzers from companies including Abbott, Roche, and Siemens
- Half of the investigated assays achieved Six Sigma on the DxI 9000 analyzer
- Up to 30% of competitor platforms showed 2–3 sigma, indicating potential failure in future proficiency testing
