July 2020

The importance of standardisation of diagnostic measurements in the COVID-19 pandemic

As the UK’s designated institute for chemical and bio-measurement, the National Measurement Laboratory (NML) at LGC delivers world-leading measurement science to solve complex global challenges, ensuring trust and confidence in the thousands of measurements performed routinely within the UK to improve quality of life.

The NML at LGC is leading an international comparison study with national measurement laboratories worldwide, to ensure increased accuracy of molecular diagnostic tests across nations by supporting the standardisation of these measurements.

Dr Jim Huggett, Principal Scientist at the NML at LGC, recently answered some of our questions around why standardised measurement is so important to medicine.

What do we mean by ‘standardisation of diagnostic measurement’?

Standardisation of diagnostic measurement refers to mechanisms that aim to ensure COVID-19 testing is performed to the same level by different laboratories, providing clinicians and patients with confidence in the test.

Standardisation provides an anchor for measurements made in multiple places and by different scientists. This will provide increased consistency and reliability in the tests performed by diagnostic and testing labs.

For example, those who live with diabetes routinely measure their blood sugar to guide their insulin use. The hand held testers they use are supported by an infrastructure of standard materials, methods and guidelines to ensure the results are working to clearly defined criteria and are comparable no matter where in the world the test is taken. The individual may not realise it, but this is giving them the confidence to trust the result, which in turn enables them to manage their diabetes.

In the case of COVID-19, as the situation has developed at an unprecedented speed, laboratories across the world have developed their own diagnostic methods to meet the urgent demand. This is made possible by the advances in molecular biology enabling new methods to be designed and ready to measure the virus within as little as a week. But this also provides considerable challenges when ensuring test confidence so that physicians and public health officials attempting to manage the pandemic know to trust the diagnostic results.

How do you ‘measure’ a virus?

The viral genome was initially purified and sequenced. Armed with this sequence information, molecular biologists were able to design highly sensitive molecular assays (such as PCR) that target viral genes to measure its presence in a patient sample and diagnose them with COVID-19.

Why does standardisation of diagnostic measurement matter and what is its impact on everyday life?

Standardisation of the measurement methods will mean that we can support robust application of the methods for testing and provide a better understanding of the virus’s behaviour.

Measurement standards will support testing confidence, such as reducing the risk of false negative results. There is a lot we currently don’t know about the virus, and having methods we know are robust will ensure we can have more reliable and consistent results, in turn providing a better understanding of the virus’s behaviour and the knowledge needed to respond to the challenge. This will ultimately give us insight into patient management and developing treatments or vaccines.

Governments are using data generated from these tests to inform public health action. Ensuring global equivalence of test performance enables more meaningful exchange of information between countries and government agencies and maximises its value in contributing to their decision-making.

What does LGC do to support research on the standardisation of COVID-19 measurement?

The NML at LGC has led the international study of a reference method for a ribonucleic acid (RNA) sequence representative of Covid-19 with the view to reach international agreement.
We are also collaborating with local UK NHS hospital contacts to assist their clinical development and utilisation of Covid-19 testing at the frontline.

As an already appointed expert laboratory relating to external quality assurance testing in virus genome detection, the NML at LGC is also part of the planned clinical measurement activities on Covid-19 being considered by INSTAND consortium - an interdisciplinary, not-for-profit, scientific medical society organising external quality assurance in nearly all areas of laboratory diagnostics.

Watch this video to hear from Jim about the importance of standardisation.