Evaluation of a collaborative model for successful implementation of a National CD4 enumeration EQA program in...

Area of Science:

• Clinical diagnostics
• Public health laboratory services
• Immunology

Background:

• Accurate CD4 T-cell enumeration is vital for managing HIV patients on antiretroviral therapy (ART).
• External Quality Assessment (EQA) programs are crucial for ensuring laboratory testing quality and reliability.
• The study addresses the need for robust EQA in resource-limited settings.

Purpose of the Study:

• To evaluate the performance and trends of an EQA program for CD4 T-cell enumeration in Cameroon.
• To identify challenges in pre-analytical, analytical, and post-analytical phases of CD4 testing.
• To demonstrate the impact of continuous training and corrective actions on laboratory performance.

Main Methods:

• Collaboration between the CIRCB (CD4 reference laboratory) and the Canadian Quality Assurance System International (QASI) program.
• Distribution and analysis of CD4 panels to 61 participating sites across Cameroon from 2014 to 2018.
• Trend and performance analysis across pre-analytical, analytical, and post-analytical testing phases.

Main Results:

• Increased participation from 15 to 61 sites over four years.
• Significant reduction in unacceptable results from 50% to 10%.
• Identified key error sources: 77.0% in the analytical phase, 17.5% in the pre-analytical phase, and 5.5% in the post-analytical phase.

Conclusions:

• Continuous training, good laboratory practices, and stakeholder collaboration are essential for successful EQA implementation.
• EQA programs require on-site corrective measures and timely equipment maintenance to minimize errors.
• The established EQA model, in partnership with QASI, can be extended to other HIV diagnostics (viral load, EID) and serves as a model for resource-limited countries.