Safety in numbers
The pandemic brought a decade-old project out of hibernation, but now EAVE II’s success in using health data to fight Covid-19 could point to the future of combating other diseases.
On 23 March 2020 Prime Minister Boris Johnson announced the most significant set of restrictions on British life in living memory.
The nationwide lockdown was designed to control the spread of Covid-19 across the UK, which at that point had taken 335 lives.
During this period of collective anxiety and fear, a team of experts led by the University of Edinburgh were in the early stages of resurrecting a project that would soon become an integral tool in Scotland's fightback against the disease.
Researchers claimed EAVE II (Early Pandemic Evaluation and Enhanced Surveillance of Covid-19) would track the spread of the disease across the Scottish population in near real time and measure the effectiveness of interventions like vaccines.
Almost a year-and-a-half later, the team has more than delivered on its ambitious promise, producing a range of reports that have played a vital role in shaping the policies of both the Scottish and UK governments.
And they are just getting started.
A key decision
The brainchild of infectious diseases epidemiologist Colin Simpson, who was then a senior research fellow at the University of Edinburgh, the first EAVE study was designed to combat the 2009 swine flu pandemic.
Funded by the National Institute for Health Research (NIHR), it used health data from a Scotland-wide group of 227,000 people across 40 general practices to assess the effectiveness of vaccines.
While an important piece of academic work, they did not deliver their findings until 2012 – too late to have an impact on government policy.
However, as Professor Aziz Sheikh, director of the University of Edinburgh's Usher Institute and the lead on EAVE II, explains, there was a key decision made at that time that allowed the project to swiftly take flight when the seriousness of the Covid-19 pandemic became apparent.
"The key masterstroke in all of this was the decision of Dame Sally Davies, the Chief Medical Officer of England at the time, to give us the resources to put the EAVE platform into hibernation, rather than scrapping it altogether," he explains.
"Permissions were put in place so in the event of another pandemic breaking we wouldn't have to start from scratch.
"We put in a bid together with Public Health Scotland and academic partners at the Universities of Strathclyde, Glasgow and Aberdeen to use the platform to help combat Covid-19. Not only were we told by the Scottish Government that they wanted it to be used as part of the national response, they wanted it scaled up. Rather than a quarter of a million people like last time, they wanted the whole population of Scotland included."
Near real-time data
Once out of hibernation, EAVE II swiftly became a crucial tool in Scotland's initial understanding of, and subsequent fightback against, Covid-19.
Thanks to Scotland's Community Health Index (CHI) register, held at Public Health Scotland, the team had access to near real-time data from 5.4 million people across the country.
Connecting information on hospital admissions, accident and emergency visits, laboratory test results, and prescriptions, the CHI data allowed the team to monitor Covid-19's impact across Scotland and on different age groups, including those most at risk.
Once scrutinised by a world-class team of analysts from both the University of Edinburgh and Public Health Scotland, these data were turned into reports that directly influenced Scottish and UK Government decisions on when to implement and lift public health measures like lockdowns and social distancing.
One such report shone a light on how the vaccination roll out in Scotland was linked to a substantial reduction in the risk of Covid-19 hospital admissions in early 2021. Others investigated the links between vaccines and blood disorders, and how the vaccines are faring against the Delta variant.
Asked why the work of EAVE II has been so integral to Scotland's Covid-19 response, Professor Sheikh says: "We are not drawing on samples; we have access to the data of the entire population of Scotland.
"Also, so much of this work is predicated on trust. Trust in the team, trust in the methods, and trust in the way our findings are reported.”
Trusted research environment
While the project has been led by the University of Edinburgh, it has been a truly collaborative effort involving experts from the Universities of Strathclyde, Aberdeen, Glasgow and St Andrew’s, Public Health Scotland, and the West of Scotland Specialist Virology Centre.
"This has genuinely been a 'Team Scotland' approach," Professor Sheikh adds. "Experts from across the country have knocked on the door, wanting to roll up their sleeves and join the national effort. We've welcomed them with open arms."
The success of EAVE II is multi-faceted, but a crucial component of its ability to deliver such important insights has unquestionably been the team's access to the health data of almost all of Scotland's population.
Handling these data requires the strictest of safeguards and an unwavering commitment to protecting the identities of individuals. Public Health Scotland and the University of Edinburgh have a proven track record in these areas, as do the other universities involved.
Public Health Scotland holds the data and analysis of all data sets is done by the study team within the National Safe Haven of Public Health Scotland under the direct supervision of Professor Chris Robertson. It is done using pseudonymised data – information that does not identify an individual because identifiers have been removed or encrypted.
"The analysis is being conducted in a trusted research environment by trained, vetted analysts," Professor Sheikh says. "There are a significant number of safeguards in place and important checks on what we disclose. These are public data and we insist that these are protected and used sensibly and appropriately."
Other disease areas
EAVE II's work is focussed solely on Covid-19 at the moment, and is likely to be used to help Scotland and the UK prepare for future pandemics.
Professor Sheikh, however, believes there is significant scope for the platform to be used in other disease areas.
"Health systems are typically flying blind without access to the data they need or working from data that are out of date," he says. "This system could provide decision makers with more contemporaneous data to help combat diseases like cancer, cardiovascular disease, and diabetes in Scotland and across the UK."
Given its already impressive impact and exciting potential, it appears unlikely EAVE II will be put back into hibernation anytime soon.
Research Insights: health data - what's in it for you?
Professor Aziz Sheikh is one of the most experienced data scientists in the world. He is Director of the Usher Institute, where he leads teams of public health researchers whose work has helped guide us through the Covid-19 pandemic.
Dr Eleftheria Vasileiou is a public health researcher who uses health data to try to predict the best vaccination programme to protect people from seasonal flu, particularly those with asthma and Covid-19.
Sandra Jayacodi advises research scientists on how best to include public and patient voices in their research.
Recorded via Zoom on 19/01/22.
- Video: Research Insights: health data - what's in it for you?
- What is health data? How does information about people’s health help to inform public health policy decisions? And how is data kept safe and secure? Speakers Professor Aziz Sheikh is one of the most experienced data scientists in the world. He is Director of the Usher Institute, where he leads teams of public health researchers whose work has helped guide us through the Covid-19 pandemic. Dr Eleftheria Vasileiou is a public health researcher who uses health data to try to predict the best vaccination programme to protect people from seasonal flu, particularly those with asthma and Covid-19. Sandra Jayacodi advises research scientists on how best to include public and patient voices in their research. Recorded via Zoom on 19/01/22.
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Photo credits: Main image - Orbon Alija/Getty; woman and data screen - Laurence Dutton/Getty