External quality control performance in clinical chemistry: experience in Kenya

Area of Science:

• Clinical Chemistry
• Laboratory Medicine
• Quality Assurance

Background:

• External Quality Assessment Schemes (EQAS) are crucial for monitoring laboratory performance.
• Participation in EQAS helps identify areas for improvement in clinical chemistry testing.
• The Kenyatta National Hospital (KNH) clinical chemistry laboratory engaged in an International External Quality Assessment Scheme (IEQAS).

Purpose of the Study:

• To evaluate the performance of the KNH clinical chemistry laboratory during an IEQAS.
• To identify discrepancies in biochemical test results using different statistical methods.
• To determine factors contributing to poor laboratory performance.

Main Methods:

• Analysis of eleven biochemical laboratory tests using a Technicon SMA II continuous flow system.
• Manual assay of glucose using the glucose oxidase method.
• Statistical evaluation of results using Standard Deviation Index (SDI) and Variance Index Score (VIS).

Main Results:

• Twenty-six percent of results were outside the 2 standard deviation (2SD) limit when using SDI.
• Forty-two percent of results were identified as outliers when using VIS.
• The laboratory demonstrated poor performance compared to international benchmarks in both IEQAS and UKEQAS.

Conclusions:

• The KNH laboratory's performance in the IEQAS was suboptimal.
• Discrepancies in outlier detection were observed between SDI and VIS methods.
• Poor performance was linked to equipment issues, reagent scarcity, lack of quality control materials, and insufficient staff training.