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INTERNATIONAL JOURNAL OF LATEST TECHNOLOGY IN ENGINEERING,
MANAGEMENT & APPLIED SCIENCE (IJLTEMAS)
ISSN 2278-2540 | DOI: 10.51583/IJLTEMAS | Volume XV, Issue VI, June 2026
Methods: narrative review approach
This manuscript was developed as a narrative review and practice-oriented quality-improvement framework.
Relevant literature was identified through searches of PubMed, Google Scholar, Scopus/Web of Science and
institutional guideline repositories using combinations of the terms clinical biochemistry, turnaround time,
laboratory quality indicators, ISO 15189, analytical quality, risk-based quality control, sigma metrics,
autoverification and total testing process. The literature window prioritised publications from 2007 to 2025,
while retaining foundational international standards and guidance documents regardless of publication year.
Priority was given to international standards, consensus guidance and peer-reviewed studies addressing TAT,
analytical reliability and laboratory quality management. ISO 15189:2022, the WHO Laboratory Quality
Management System handbook, CLSI EP23 guidance and IFCC quality-indicator work were used as core
normative sources [1-4,7,8]. Empirical and review literature on laboratory TAT, pre-analytical and post-
analytical quality indicators, sigma metrics, automation and benchmarking was used to translate these principles
into an operational framework [5-13]. Sources that focused exclusively on non-clinical laboratory systems,
research-only assay development or unvalidated local opinions without transferable quality-management content
were not prioritised. Because the purpose was to build a clinically usable QMS framework rather than to estimate
pooled intervention effects, no meta-analysis was performed. Instead, the synthesis organised the literature
around five questions: how should diagnostic TAT be defined, which phases generate measurable delay, which
analytical controls protect the reliability of results, how can speed and reliability be governed together, and which
indicators should be used to verify sustained improvement.
Screening transparency: the original narrative search was not prospectively registered, and database exports were
not retained in a form that permits a reliable reconstruction of the total number of records initially identified. For
this revision, the 13 full-text sources in the working evidence set were re-screened against the stated eligibility
criteria, and all 13 were included in the final synthesis: four standards or consensus resources and nine peer-
reviewed publications. No meta-analysis or formal risk-of-bias assessment was undertaken. These figures should
therefore be interpreted as an audit of the evidence actually used in the manuscript, not as a PRISMA-style
systematic-review flow.
Conceptual basis: quality management as a diagnostic-control system
A useful way to conceptualise a clinical biochemistry laboratory is as a diagnostic-control system. Inputs are test
requests and patient specimens; processes include pre-analytical, analytical, and post-analytical activities;
outputs are validated diagnostic results; feedback is provided through quality indicators, internal audits, external
quality assessments, incident reviews, user complaints, and management reviews. Without feedback, the
laboratory merely performs tests. With feedback, the laboratory learns. ISO 15189:2022 emphasises competence,
risk, impartiality, patient focus and the management system needed to sustain valid examination results [1]. The
WHO LQMS model similarly organises laboratory quality around coordinated essentials such as personnel,
equipment, purchasing and inventory, process control, documents and records, occurrence management,
assessment and continual improvement [2]. These are not simply accreditation headings. Each one maps directly
onto failures that delay results or damage analytical credibility.
For example, equipment management affects both reliability and TAT through preventive maintenance,
downtime planning, backup analysers, service-level agreements and calibration schedules. Personnel
management affects the quality of results through competency assessment and authorisation to perform or
validate tests. Process control governs collection instructions, sample acceptance criteria, QC rules, auto-
verification protocols, and corrective action thresholds. The QMS is therefore the architecture through which
laboratory speed becomes safe speed.