Laboratory Quality Management
This domain tests the laboratory quality management system needed for reliable, traceable and patient-centred testing. It draws on ISO 15189 concepts: document control, competence, equipment, internal quality control, external quality assessment, nonconforming event management and continual improvement.
Core QMS elements
A quality manual and controlled documents define policies, processes and records. Personnel must be trained and competency-assessed. Equipment and reagents must be selected, verified, calibrated where required and maintained. Internal QC monitors precision and stability within each run; EQA/proficiency testing provides external comparison. Nonconformities, complaints and adverse events feed root-cause analysis and corrective action. Audits and management review test whether the system actually works.
QC and EQA interpretation
Use defined acceptance criteria before patient testing. A QC failure triggers rejection of the run, investigation, correction and documented release only after acceptable performance is restored. EQA results must be reviewed by authorised staff, with investigation of unacceptable performance and evidence of corrective action. Trends matter: a shift or drift can signal calibration, reagent or environmental problems before a single point fails.
Worked example: a chemistry control shows eight consecutive points above the mean on one side of the Levey-Jennings chart. This is a shift, not random variation. The laboratory should stop reporting affected patient results, check calibrator and reagent lot changes, review maintenance and temperature records, repeat with fresh control, and document root cause and corrective action before resuming.
Traps
- Repeating QC until it passes without investigation.
- Ignoring an EQA failure because routine QC looks acceptable.
- Using expired reagents or uncalibrated equipment.
- Recording corrective action only verbally.
- Treating the quality manual as a shelf document rather than a controlled system.