In England, testing was an important public health intervention during the COVID-19 pandemic – allowing the Government to monitor disease transmission and forming the cornerstone of self-isolation policies.
However, analysis of testing data, combined with England’s voluntary surveillance study which included people in every area of the country, has highlighted systematic biases, with gaps in uptake among sociodemographic groups. The study was part of a high-profile evaluation of England’s COVID-19 testing programme undertaken by Ernst & Young and Oxford University Innovation commissioned by the UK Health Security Agency, led by Professor Lisa White (Department of Biology).
Researchers analysed data from 390 million LFD (Lateral flow device) and PCR (Polymerase chain reaction) tests taken from October 2020 to March 2022, which were made freely available to the public. Their findings highlight the need for equitable public health strategies to ensure fair access to health interventions. For example, a future response could see local public health practitioners monitor intervention uptake in risk groups in real time, and adapt where inequities appear.
Dr Sumali Bajaj (Lead author, Department of Biology at the time of the study, now Merton College and Department of Statistics at Oxford) said:
“This study presents a framework and real-time metrics for evaluating the effectiveness of public health interventions among vulnerable groups at the local level. Data from interventions, such as testing, can be used opportunistically to help improve public health responses.”
While people across the country were more likely to perform LFD than PCR tests regardless of their infection status, from March 2021 onwards those in the most deprived regions reported half the LFD tests per person than those in the least deprived areas. This might be due to lower digital access to report LFDs in these areas, and the absence of adequate support for people to isolate if they tested positive.
Professor Ben Lambert (Senior author, Department of Statistics at Oxford) said:
“There will be a next pandemic, and our work demonstrates how the UK’s testing infrastructure for COVID-19 could be deployed to monitor testing uptake and reporting in groups traditionally missed by public health surveillance.”
Infection prevalences in Asian or Asian British communities were considerably higher than those of other ethnic groups during the Alpha and Omicron BA.1 waves. Ethnic minorities and older individuals were less likely to use confirmatory PCR tests through most of the study period, and there was possibly a longer delay in testing or reporting a positive LFD test in Black populations. Differences in testing behaviours across sociodemographic groups may be reflective of the relatively higher costs of self-isolation to vulnerable populations, differences in test accessibility, digital literacy, and differing perceptions about the utility of tests and risks posed by infection.
The study demonstrates how real-time data can guide more targeted and effective interventions. This could help improve public health responses in future pandemics, especially for minority risk groups and deprived regions.
Dr Reshania Naidoo (co-PI for the evaluation, EY, Nuffield Department of Medicine at Oxford) said:
“In addition to the key implications of our findings for future public health surveillance strategies, our work also underscores the need for a joined-up data infrastructure in the public health system across England so that we can readily respond to future health emergencies’’
Dr Tom Fowler (Director for COVID-19 testing, UK Health Security Agency) said:
“A key area of learning from the Covid 19 pandemic is how our response impacted health equity. This national study looking at sociodemographic groups testing and reporting gives key insights for future planning, and critically suggests a methodology that would enable better targeting of testing in a future pandemic response.”
To read more about this research, published in The Lancet, visit: https://doi.org/10.1016/S2589-7500(24)00169-9
