[1] C. Price, A. St john and J. Hicks, “Point-of-care testing”, 2004. [Online]. Available: http://mldt.hu/upload/labor/document/PRICEP.pdf. [Accessed: 23- Jul- 2018].

[2] C. Price, “Point of care testing”, BMJ, vol. 322, pp. 1285-1288, 2001.

[3] A. Okorodudu, “Optimizing accuracy and precision for point-of-care tests”, Acutecaretesting.org, 2011. [Online]. Available: https://acutecaretesting.org/en/articles/optimizing-accuracy-and-precision-for-point-of-care-tests. [Accessed: 24- Jul- 2018].

[4] H. Holt and D. Freedman, “Internal quality control in point-of-care testing: where’s the evidence?”, Annals of Clinical Biochemistry, vol. 53, no. 2, pp. 233-239, 2016.

[5] “ISO 22870:2016 – Point-of-care testing (POCT) — Requirements for quality and competence”, Iso.org, 2018. [Online]. Available: https://www.iso.org/standard/71119.html. [Accessed: 25- Jul- 2018].

[6] J. Gill and M. Shephard, “The Conduct of Quality Control and Quality Assurance Testing for PoCT Outside the Laboratory”, Clin Biochem Rev., vol. 31, no. 3, pp. 85-88, 2010.

[7] A. Stavelin and S. Sandberg, “Essential aspects of external quality assurance for point-of-care testing”, Biochemia Medica, pp. 81-85, 2017.

[8] C. Price, I. Smith and A. Van den Bruel, “Improving the quality of point-of-care testing”, Family Practice, vol. 35, no. 4, pp. 358-364, 2017.

[9] “ISO 15189:2012 – Medical laboratories — Requirements for quality and competence”, Iso.org, 2018. [Online]. Available: https://www.iso.org/standard/56115.html. [Accessed: 31- Jul- 2018].

[10] J. Crilly, “Mythbusting: Frequency of EQA Reports”, Randox Laboratories, 2017.

[11] G. Kristensen and P. Meijer, “Interpretation of EQA results and EQA-based trouble shooting”, Biochemia Medica, pp. 49-62, 2017.

External Quality Assessment (EQA) / Proficiency Testing (PT) allows for a comparison of a laboratory’s testing procedures to other laboratories across the world. Comparisons can be made to a peer group of laboratories or to a reference laboratory.

EQA involves running blind patient-like samples, comparing your results to peer results, in order to retrospectively monitor the accuracy of reporting. EQA samples should be treated as if they were a patient sample and therefore must be run by personnel who would normally use the device. This provides confidence in the reliability of patient test results.

Participating in an EQA scheme allows a laboratory to gather valuable data, this data can be used in a variety of ways ^[1]:

EQA provides assurance to both staff and customers that testing taking place at your laboratory provides accurate and reliable results. Problems can be identified early on and corrective action can be untaken. The reliability of methods, materials, and equipment can be evaluated and training can be developed and its impact monitored.

Large laboratory groups can compare their performance with sites across their group, ensuring accuracy and consistency no matter where testing takes place.

EQA participation is often a requirement for accreditation, gaining accreditation alone has a host of benefits, not least an increased confidence in results from customers, current and potential.

Point of care testing (POCT) refers to testing that is performed near or at the site of a patient with the result leading to a possible change in the care of the patient. The popularity and demand for POCT has recently seen rapid growth, this comes from the advantages including the added convenience of being able to obtain a rapid result at the patient’s bedside, thus allowing immediate action, saving time and improving the potential outcome for the patient.

Although there are many benefits of using POCT devices in terms of their convenience, these benefits are only true if the results produced are both accurate and reliable. Ensuring accuracy and reliability is the primary responsibility of Quality Control.

EQA is strongly recommended for all point of care devices and is recommended by ISO 22870, which providesspecific requirements applicable to point-of-care testing and is intended to be used in conjunction with ISO 15189.

There are many External Quality Control schemes that come in different varieties. EQA schemes can be mandatory, required either by accreditation or law. Others are voluntary and carried out by laboratories who want to ensure that they are carrying out accurate testing and improve the quality of the lab’s performance ^[1].

A good EQA scheme should offer:

EQA is a great tool for comparing against a peer group and maintaining an effective QC strategy, however, it has its limitations.

EQA / PT alone cannot provide a complete evaluation alone; it is important to also run third party controls regularly. You can find out about the importance of third party controls here.

EQA results can also be affected by variables not relating to patient samples, including preparation, clerical functions, matrix effects, and selection of method. The errors can appear to be a downside to EQA but it can be used as a way to evaluate staff performance as well as assay performance.

If possible, every laboratory should participate in an EQA scheme that covers all testing procedures. Laboratories need to develop a management process with the objective to assure that EQA samples are treated appropriately and in the same manner. This includes, sample handling, sample analysis, record keeping, investigating deficiencies, taking corrective actions, and communicating results with laboratory staff and management.

Problems at any stage of sample analysis can cause errors, when an error does happen, all elements of the process need to be checked. Some examples of errors:

Pre Analysis

•  Incorrect sample handling during preparation, shipping or storage

•  Improper storage

•  The material has expired

•  An error in manufacturing

Analysis

•  Instrument, calibration or reagent defects

•  Staff competency

•  Matrix effects

•  Incorrect analysis method

Post Analysis

•  Report misinterpretation

•  Clerical or transcription errors

•  Failure to take corrective action

[1] WHO, Overview of External Quality Assessment (EQA). World Health Organisation, 2009.

[2] ISO 15189:2012 Medical laboratories — Requirements for quality and competence, 3rd ed. ISO, 2014.

[3] ISO 22870:2016 Point-of-care testing (POCT) — Requirements for quality and competence, 2nd ed. ISO, 2016.