IJCA Vol 5 Issue 1 - Flipbook - Page 48
The International Journal of Conformity Assessment
2026 | Volume 5, Issue 1
The Role of External Quality Assessment (EQA) in
Laboratory Services
By Vikash Chandra Mishra, PhD, Quality Manager, Chimera Transplant Research Foundation, New Delhi,
India; Dinesh Chandra, MSc (Biotechnology), Assistant Quality Manager, Chimera Transplant Research
Foundation, New Delhi, India; and Vimarsh Raina, MD (Pathology), Medical Director, Chimera Transplant
Research Foundation, New Delhi, India.
GENERAL INFORMATION
DOI: 10.55459/IJCA/v5i1/VM.DC.VR
Keywords: External Quality Assessment, EQA, Quality
Control, Pro昀椀ciency Testing, Laboratory Quality
ABSTRACT
External quality assessment (EQA) is an important
tool in laboratory services, ensuring the accuracy,
reliability, and consistency of diagnostic test
results. In an EQA program, an external body
distributes unknown samples to participating
laboratories, which analyze them and report
their results for comparison with those of peer
institutions. This process enables laboratories
to identify errors, monitor performance trends,
and implement corrective measures. This article
outlines the concept, process, importance, and
challenges of EQA and highlights its role in
supporting patient safety and healthcare quality.
INTRODUCTION
External quality assessment (EQA) in laboratory
services was first introduced in the 1950s and
1960s, in response to the growing need for
independent verification of test accuracy and
reliability [1]. Unlike internal quality control (IQC),
which relies on internal checks, EQA — also known
as proficiency testing (PT) - provides an objective
external benchmark against a wider peer group
[2]. Globally, several organizations coordinate EQA
schemes, including the World Health Organization
(WHO), the College of American Pathologists
(CAP), and the United Kingdom National External
Quality Assessment Service (UK NEQAS) [3–5].
In addition, numerous national and regional
programs support laboratories in monitoring
performance across diverse healthcare settings.
Over time, EQA schemes have expanded beyond
core chemistry and hematology testing to include
molecular diagnostics, microbiology, and pointof-care testing (POCT), reflecting the increasing
complexity of laboratory services.
Laboratory testing forms the backbone of modern
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healthcare, guiding diagnosis, treatment, and
disease monitoring. Ensuring the accuracy,
reliability, and consistency of test results is
therefore essential for safe and effective patient
care. While IQC is routinely used to monitor day-today analytical performance, independent external
evaluation through EQA provides an important
complementary benchmark for validating results
and identifying performance gaps [2].
In an EQA program, an external body distributes
unknown samples to participating laboratories,
which analyze them under routine conditions and
submit results for comparison with those of peer
institutions. The primary purposes of EQA are to
ensure reliable test results, monitor laboratory
performance, and promote patient safety by
minimizing diagnostic errors and supporting
appropriate clinical decision-making. This article
highlights the role of EQA in supporting staff
competency, fostering confidence in laboratory
results, and maintaining high-quality laboratory
services.
How EQA Works
The external quality assessment process follows
a structured, step‑by‑step work昀氀ow designed to
evaluate laboratory performance under routine
testing conditions [6]. The typical EQA process
begins with the distribution of unknown samples,
whereby participating laboratories receive
characterized specimens from the EQA provider.
These samples are analyzed under routine
laboratory conditions, in the same manner as
patient specimens. After testing, laboratories
submit their results to the EQA provider for
comparison with those of peer laboratories and for
statistical analysis.
Based on this evaluation, participating laboratories
receive a detailed performance report that
highlights errors, performance trends, and areas
for improvement, along with recommendations
where appropriate [7]. Commonly assessed
parameters include accuracy, which measures how
close results are to the assigned value; precision,
which assesses repeatability; and consistency with
