Are accreditation standards fit for measurement uncertainty in clinical laboratories? An analysis of Saudi Arabia's accreditation.

Background: Measurement uncertainty (MU) is a fundamental aspect of laboratory quality management and is required by many international accreditation standards, including ISO 15189 and CAP ISO 15189. Nevertheless, its regulatory status under Saudi Arabia's national accreditation system (CBAHI) remains unclear. This study aimed to examine the extent to which CBAHI accreditation standards implement the MU and their potential effect on patient safety. Methods: This study used a structured standards gap analysis to investigate MU coverage in CBAHI clinical laboratory standards. We analyzed seven CBAHI laboratory standards that are applicable to MU. This was against eight MU-related analytical domains derived from ISO 15189:2022. Alignment was scored on a 3-level scale (0 = no explicit requirement, 1 = partial alignment, 2 = full alignment). Then, we developed comparative benchmarking that compares MU expectations across ISO 15189:2022, the CAP 15189 accreditation program, and CLSI guidance. A biological variation framework from the EFLM Biological Variation Database was used to derive analytical performance specifications (APS) for MU. We focused only on high-impact analytes responsible for diagnosing high-impact diseases. Results: CBAHI standards exhibited moderate to high alignment with ISO 15189:2022 in conventional analytical quality domains, such as internal quality control, proficiency testing, calibration, and integration within the quality management system. Critically, MU lacked explicit coverage across all seven CBAHI standards (score 0). In contrast, many international guidance and standards consider MU a fundamental, mandatory requirement, including ISO 15189:2022, CAP ISO 15189, and CLSI guidance. The biological-variation-based APS for 10 clinical chemistry analytes were frequently close to commonly used diagnostic thresholds, underscoring the potential for theoretical misclassification when MU is unquantified. Conclusion: The current CBAHI clinical laboratory accreditation framework does not incorporate explicit requirements for MU estimation, performance limits, or clinical reporting. It is crucial to enhance national standards by incorporating MU-focused clauses, providing technical assistance, and integrating them into regular quality management processes. These measures are important for aligning CBAHI with global best practices and reducing the theoretical risk of diagnostic misclassification at critical decision points.