Whole area testing with lateral flow device (LFD) tests in Merthyr Tydfil and lower Cynon Valley is estimated to have prevented 353 cases of COVID-19, 24 hospitalisations, 5 Intensive Care Unit admissions and 14 deaths, according to a new report.
An evaluation of the pilot, released today (Monday March 22) by the partner organisations who delivered the initiative, found that identifying cases of COVID-19 in asymptomatic people through mass lateral flow testing saved lives and prevented hundreds of cases of the virus at a time when rates were extremely high in these areas.
The evaluation also found that:
- The pilot caused an immediate reduction in the level of COVID-19 in the areas;
- When taking into account the onward transmission of infection in the community expected from people who would not have known they had COVID-19, more than a tenth of cases that would have otherwise occurred were prevented. This represents a 6-12% reduction in pressure on the NHS;
- The estimated net monetary benefit of the testing pilot was £5.8 million, which means a benefit:cost ratio of around 11 for the £516,000 the pilot cost, or a return on investment of around £10.30 per £1 spent.
The whole area testing pilot took place in November and December 2020, with the aim of reducing the spread of Coronavirus in areas with high incidence and positivity rates.
The pilot was the result of an unprecedented collaboration between partners including the local authorities, Health Board, Welsh Government, the military, police and Welsh Ambulance Service, as well as schools and the Third Sector.
The evaluation found uptake of the testing pilot was high. 22,021 people were tested in Merthyr Tydfil, representing nearly half of the target population (49%). A further 10,457 people were tested in lower Cynon Valley, which represents 56% of the target population. This is close to double that of the Liverpool and Scottish pilots.
The positivity rate was 2.3% in Merthyr Tydfil and 2.6% in lower Cynon Valley. The report found higher positivity rates in these key demographics:
- Younger people;
- People living in the most deprived areas;
- Occupations where close contact is more likely, such as transport and hospitality, manufacturing and construction, health and social care, retail and arts and entertainment.
The evaluation found a high degree of assurance around lateral flow device (LFD) testing, as the tests showed good performance in identifying asymptomatic infections, suggesting a different but complementary role to PCR tests which are used mainly to diagnose symptomatic infections. Between one in four and one in three people who have Coronavirus never show any symptoms, so LFD tests can help identify people with the virus who do not have symptoms and would not otherwise come forward for a test.
A range of additional successes were also identified, including joint working across organisations, high levels of community engagement, the speed at which the pilot was implemented and the commitment and dedication of staff in getting the pilot underway.
Other conclusions from the evaluation include:
- The vast majority (99.6%) of those attending the mass testing centres were asymptomatic, showing the community understood the purpose of testing and presented appropriately;
- Transmission within households was the most important source of infection;
- Working in the hospitality sector and visiting the pub were also significant risks but due to the COVID-19 restrictions at the time, these were infrequent exposures;
- Smoking or vaping had a small but significant effect;
- Working in education, living with someone working in education, having caring responsibilities and visiting a supermarket, restaurant, gym or leisure centre did not appear to increase risk of infection;
- The lower testing uptake in groups of the population with higher positivity rates has clearly demonstrated an “inverse testing law”. This will be important in informing future testing strategies.
The report recommends:
- The use of mass testing for asymptomatic members of the community should be considered an important and effective part of any COVID-19 control plan;
- Use of LFD testing in the community should be targeted at areas and groups at higher risk of infection. A follow up PCR test within 24 hours is recommended to ensure that cases and contacts from a small number of false positive results are released from self-isolation;
- Testing should be targeted in more deprived areas, at men, younger people and occupations with close contact who cannot work from home, for example transport, construction and manufacturing, personal services such as hair and beauty and health and social care;
- Contact tracing should be fully integrated into the work to follow up cases for isolation and support to ensure compliance and break chains of transmission;
- It is essential that implementation is locally led, in partnership with local authorities, health services and the Third Sector;
- Good communication and engagement with community members and local businesses is needed to secure good uptake.
Professor Kelechi Nnoaham, Director of Public Health for Cwm Taf Morgannwg University Health Board, said: “I’m excited to share this report evaluating the success of our Whole Area Testing pilot. This was a very ambitious pilot which was delivered at pace with the aim of making a significant difference to our communities at a time when rates of COIVD were sadly extremely high in these areas.
“The results speak for themselves, with a conservative estimate of more than 350 cases of COVID-19 and 14 deaths prevented. This is not only positive news for our communities, but the evaluation shows that the pilot eased the pressure on our hospitals and key workers when it was most needed, and was a good investment, with a total benefit in monetary terms of £5.8million.
“I believe this report will be invaluable to anyone interested in using lateral flow device testing as part of a wider testing strategy, both in Wales and around the world. It shows that LFD testing has the potential to be a key part of our Test Trace Protect system as we look more confidently towards recovery, and provides real experience for other areas considering a similar approach. The full evaluation report provides a blueprint for others to use.
“I’d like to thank the partners who collaborated with us at all stages of the process, and the communities who engaged with us to make sure it was a success. Without their dedication and hard work, a pilot of this scale would not have been possible.”
A summary of the report and links to the full report can be found below:
NEW AND UPDATED Executive Summary
NEW AND UPDATED Full Report
Of note: In the updated report, the section on assessment of accuracy of LFD tests has been removed. Associated references to the subject have also been removed. The accuracy of LFD tests in identifying infection was assumed for this pilot based on relevant studies and the data we collected in the pilot was not amenable to analysis of test accuracy.
For interview bids with Prof Kelechi Nnoaham, please email CTM.News@wales.nhs.uk.