Quality Assurance and Analytical Error Reduction Strategies in Clinical Laboratory Medicine: A Systematic Review of Laboratory Specialist–Led Interventions, Safety Outcomes, and Quality Improvement Practices

Abstract

Background: Clinical laboratory results inform a large share of medical decisions, yet errors across the total testing process (TTP) can compromise patient safety. Although the analytical phase now contributes a minority of laboratory errors, sustaining and improving analytical quality depends on deliberate quality assurance (QA) led by laboratory personnel. Objective: To systematically review QA and analytical-error-reduction strategies in clinical laboratory medicine, the safety and performance outcomes associated with them, and the role of laboratory specialists and technologists in their design and delivery. Methods: A focused systematic review was conducted following PRISMA 2020 principles. PubMed/MEDLINE and supplementary sources were searched for peer-reviewed English-language literature (2000–2026) combining setting, intervention (QA, quality control, Six Sigma, Lean, quality indicators, ISO 15189), and outcome (analytical/laboratory error, patient safety, turnaround time, specimen rejection) concepts. Twelve sources meeting eligibility criteria were synthesized narratively around four intervention themes. Results: Evidence consistently showed pre- and post-analytical phases dominate the error profile while analytical errors, though few, carry high clinical risk when undetected. The most reported analytical-QA strategy was risk-based statistical quality control designed around sigma metrics. Lean and Lean-Six-Sigma projects reduced turnaround time (by up to ~76% overall in one synthesis) and cut error-prone handling steps. Quality-management systems, ISO 15189 accreditation, harmonized quality indicators, and continuing competency-based training provided the governance and human infrastructure for sustained error reduction. Every strategy identified was enacted by laboratory personnel. Conclusions: Laboratory specialists are the central agents of analytical quality and patient safety. Layered, largely low-cost QA strategies—sigma-based QC, Lean improvement, accreditation, quality indicators, and training—offer a feasible route to further error reduction across diverse settings.