Why is PoCT important?

All individuals should have equitable access to accurate and timely testing for infectious diseases, which underpins diagnosis and treatment, safeguards blood supplies, and is used to determine disease prevalence.

Disadvantaged populations have limited access to laboratory-based testing, so near patient or point of care testing (PoCT) has been developed and implemented. Unlike laboratory-based testing, PoCT is often performed by non-laboratory staff and outside regulatory frameworks. Quality assurance (QA) of PoCT is often lacking or inappropriate, meaning inaccurate testing can go undetected, leading to poor patient outcomes.

Barriers to the provision of PoCT QA

In collaboration with the World Health Organization (WHO), NRL reviewed the barriers to the provision of PoCT QA and designed a process that is more fit for purpose.

Barriers to provision of quality assurance to point of care testing:

Sample types: The majority of serology PoCTs use capillary whole blood, while some use oral fluid. Uses of traditional sample types fail to assess the pre-analytical aspect of PoCT, arguably one of the most likely points of error for PoCTs.

Single-use tests: PoCTs are usually limited to single-use cartridges or devices, so any quality assurance will assess the performance of that cartridge or device only. It is then assumed that other cartridges within that kit will behave in the same manner.

Testing facilities: Testing at PoC is often performed in basic laboratory settings, community health facilities, or in non-health settings and by non-health professionals. PoCT is not always continuous due to programmatic testing, ad hoc testing or stock outs.

Access to Test Kits: Procurement of PoCT kits in some low- and middle-income countries (LMIC) can be fragmented due to poor transport coordination or lack of funding. Testing may also be associated with a short-term project, implemented at a time that does not coincide with a traditional external quality assessment (EQA) test event.

Geography: P0CTs are used in remote and regional settings. These settings are often in geographically isolated; rural communities or testing of remote First Peoples. These environments create challenges such as variable temperature and humidity, difficultly in access to reagents and QA materials. Some sites lack electricity and water.

Shipping and storage of materials: The cost of shipping infectious disease QC materials under UN3373 and on dry ice is usually prohibitive, excluding access to the programs by PoCT facilities. Appropriate storage facilities such as refrigeration or -20⁰C freezers may not be available.

Fixed Test Events: Most EQA providers have fixed test events throughout the year. Given shipping and importation difficulties, it is not uncommon for facilities to miss the testing window, thereby wasting their EQA purchase. Some facilities face difficulties in acquiring a constant source of reagents and do not have in-date reagents at the time of the EQA.

Regulations: Quality control (QC) materials are listed as in-vitro diagnostic devices (IVD) and are usually cost prohibitive to the end-user and restricts the use of in-house development of alternative products.

Qualitative Results: Generally, PoCT results for serology rapid diagnostic tests (RDTs) are qualitative, whereas the most QC processes utilise quantitative results. By formulating sample sets close to the limit of detection of serology PoCTs and collecting the results in a systematic manner can produce meaningful, statistically relevant qualitative data used for both monitoring of testing and post market monitoring.

Loss of Data: Often QA data collected is lost to follow up. Therefore, EQA is often not used for effective post market monitoring of test kit performance. By systematically collecting and reviewing the data against pre-established performance criteria, deficiencies can be detected and addressed in real time.

Disconnect between quality assurance providers and other stakeholders: It is NRLs experience that many IVD manufacturers see quality assurance providers as a threat and are often antagonistic to their findings. Large funding bodies such as Global Fund often have cursory quality assurance requirements, even though many millions of dollars are spent on procurement. There is no centralised repository of adverse events.

NRL PoCT QA

NRL has developed a novel, fit-for-purpose PoCT QA program optimised for a range of infectious disease analytes. The program is scientifically validated, comprehensive and an end-to-end solution.

In summary, it involved:

Samples: A range of dry tube and dried swab samples for molecular testing and synthetic whole blood samples for serology. Samples have been validated for shipping at ambient and storage at 4-8ᵒC for extended periods of time. All samples are validated for homogeneity and stability.

QA formats: NRL PoCT QA provides two types of quality assurance programs

• Competency panels – Generally competency panels offer single positive and negative samples for each analyte. These panels are used to train and assess the competence of testers, to monitor the performance of the testing and to release new batches of reagent. NRL suggests that testing a competency panel each week is optimum and that a minimum requirement should be once per month for sites testing low numbers of patients.
• EQAS – Generally, NRL EQA have five samples containing positive and negative samples of various genotypes/subtypes and different concentrations/viral loads/disease states. Ideally each site should test an EQA three times per year but no less frequently than once per year

Cost: Samples are manufactured in bulk ensuring low cost. As shipping is ambient and non-infectious the costs of shipping are reduced.

Panel distribution: To overcome the cost of resource-intense distribution processes, NRL aims to work with test kit manufacturers or centralised procurement facilities to distribute QA materials with the reagents.

Removal of fixed test period for EQA: NRL PoCT EQA are provided as ad hoc activities, rather than fixed test events. Our mobile phone portal and EQA design removed the risk of collusion of results.

Mobile phone QA portal: NRL has developed a mobile phone portal for the collection and analysis of QA results. All QA sample panels have a QR code that can be scanned using a smart phone. A bespoke data entry form is presented, and on submission, the results analysed in real time.

Testing Times

We are very proud to have developed a video called “Testing Times”. Calling on our extensive network of laboratories across the world, our colleagues talk poignantly about the impact of COVID-19 on their laboratory, their staff and themselves.

NRL continues to actively work to improve the quality of testing for COVID-19 through our collaboration with FIND in the roll-out of a novel Point of Care Quality Assurance program across 10 countries.