The clinical laboratory test quality control means creation and regular use of a system of measures that detects and prevents unacceptable errors that may occur in the course of laboratory tests.
The analytical process control is required to foster confidence that possible analytical errors would have no impact on the clinical significance of findings.
The full laboratory cycle includes:
The quality control system is built on the principle of standardization of all testing stages.
Pre-analytical stage –
patient preparation, sample registration and taking, transportation to the lab, sample sorting.
Analytical stage –
lab tests as such, including quality control.
Post-analytical stage –
result validation by laboratory doctors, lab certificate issue, handing the results over to the patient or their consulting physician and solving the clinical task based on the test results.
The clinical lab test quality control exists in two interrelated forms:
Intra-laboratory quality control
External quality assessment
Intra-laboratory quality control for qualitative testing using certified control materials includes:
Within-run replication (repeatability) assessment when introducing new methods or making material changes to the analytical system
Replication and correctness assessment with Levey – Jennings charts
Operational results control for every series of measurements
Parameters like standard deviation (SD) or Coefficient of variation (CVa) serve as a quantitative assessment of analytical quality.
The intra-lab quality control at Helix is performed daily. It includes assessment of all analytes via measuring control materials with varying known content levels according to the established procedure. All procedures use the HelixQC software developed by Helix specifically for that purpose.
The Helix International Medical Laboratory takes part in the inter-lab comparison programs like Unity Interlaboratory Program (Bio-Rad, USA) and SNCS IQAS Online (Sysmex, Japan) which make it possible to compare daily intra-laboratory quality control results with similar findings all over the world, thus reaffirming confidence in the tests being done.
On top of the traditional, control material-based quality control, Helix uses the mean values and moving averages analysis across patients. The mean value for every analyte, based on patient results is auto-calculated daily using LIS (Laboratory Information System) data and downloaded into a separate report. We also monitor moving averages in real time, to even better control our analytical system. If a moving average breaks the specified boundaries, the system alerts the lab technician automatically, so that they can immediately take corrective action, if needed. That procedure also helps us analyze various trends and data shifts in real patient data from multiple labs in the same chain, making a significant contribution to test results harmonization.
Unity Interlaboratory Program
Bio-Rad, USA
SNCS IQAS Online
Sysmex, Japan
The external quality assessment (EQA) is a system for the objective analysis of test results provided by multiple labs, to ensure the comparability of data.
EQA is done by third party organizations at pre-set intervals. The single center sends control samples to the laboratories to be assessed and then compares the results. The specific lab's operations are assessed depending on how much the results they've submitted deviate from the average, thus verifying that the test had been performed correctly.
The greater the deviation, the lower the lab's work quality. Helix takes part in multiple external quality assessment systems:
The external quality assessment data regularly puts Helix among the best out of the majority of the world's laboratories that use similar equipment.
Helix uses the Six Sigma methodology, the universal system for analytical efficiency assessment and process improvement, to standardize qualitative parameter results. Calculating the number of sigmas for every analyte makes it possible to assess the analytical quality level achieved.
Taking part in the Westgard Sigma Verification of Performance (Sigma VP) program by Westgard QC, Inc. (USA) and the results Helix has shown there confirm that the accuracy of our test results is in line with international standards. This verification means that statistically, only 3.4 tests per million can result in an error.
The Helix International Medical Laboratory's quality management system is in line with ISO 15189-2012 (Medical laboratories — Requirements for quality and competence) and ISO 9001-2015 (Quality management systems — Requirements) international standards, as confirmed by annual audits done by leading global companies (SGS, Switzerland and Bureau Veritas, France).