blog

As the COVID-19 pandemic highlighted drastic health inequities around the world, this year’s focus for World Health Day is to build a fairer, healthier world. As we considered health inequities in a time of COVID-19, we spoke to Rob Aldridge from University College London (UCL, UK) about UK-based research recently published with our partner platform, Wellcome Open Research, and what impact this research could have on access to essential services for other infectious diseases on an international scale.

First of all, could you introduce yourself?

I am Rob Aldridge, a Professor of Public Health Data Science at UCL. I lead a research group at UCL that is working across a number of infectious and non-infectious diseases bringing together computer scientists, epidemiologists, public health experts, anthropologists and ethicists to look at these problems as a whole. In particular, we bring data science approaches to tackling and understanding issues of inequity in health.

Could you tell us a little more about your research?

I have been looking at infectious disease and inequalities in infectious disease for a number of years. Originally, I trained as a clinician and specialized in public health, and in that work I did a lot of analyses using large data sets to understand health outcomes amongst vulnerable and marginalized populations for tuberculosis. The work that we are doing right now builds upon that, and we are looking at, not just the kind of infectious disease outcomes in those excluded and marginalized populations, but also non-communicable diseases. So, for example, we’re looking at the non-communicable disease treatments for conditions like COPD in injecting drug users.

We are also looking at non-communicable disease outcomes, such as homicide and suicide in people who have moved countries or moved international borders. More recently, we’ve been focused on the stark health inequities found in minority ethnic populations and their relationship with COVID-19 to try to understand what are the root causes of that and how we tackle it. I think a really important part of what we do in our research group is that we’re not only trying to identify and make these sometimes-invisible populations and health outcomes visible, but we also try to think about the interventions and how we can tackle those inequities prior to them occurring. So, we are identifying the problem, but also thinking about how you use the data to start to tackle it going forward.

Could you tell us about the motivations behind investigating health inequities in a time of COVID-19?

It became clear quite early in the pandemic in high-income countries (the US, UK, and the rest of Europe), that there was an issue around inequities and particularly a relationship with ethnicity. Some of the early data from the US were showing a race disparity, and in the UK at the time that we started working on the piece that was published with Wellcome Open Research, we didn’t have much data on COVID outcomes by ethnicity. We had some mortality and intensive care admissions data stratified by ethnicity, but the data set we looked at for our Research Article was the first one to use the broader hospital admission data from NHS England, with its first breakdown by ethnicity.

We showed within that that there were some very stark outcomes in terms of in hospital deaths by ethnicity, after we accounted for geographical areas where those outbreaks of COVID were occurring. In our analysis we attempted to account for some of the geographical variations in COVID infections that might have accounted for these differences, but there was still a strong ethnicity inequity even after we accounted for geography. These inequities have become even clearer and starker over the last 12 months of the pandemic.

How do you think your findings could be applied to more of an international scale? What do you think you would find if you applied your research to an international cohort?

There has been a lot of international research looking at this issue. I think each country has context specific issues, but England is very lucky in the fact that it has a national system where we can look at health records from the NHS for the whole of the country. One of the things that we are able to do really well in research in the UK is to use our national level hospitalization data. Other high-income countries would find or have found very similar issues – the specifics and the differentials in terms of the gap between minority ethnic groups might vary, but I think they will find, where available, very similar patterns to what we see in our analysis of the NHS England data.

With other conditions that perhaps don’t have the same level of urgency as COVID-19, what would you expect to find if you were applying this sort of research in those areas?

We do already see these really stark inequalities with tuberculosis. I’m fairly certain that with other respiratory infectious diseases that we see circulating each year – influenza, human metapneumovirus, respiratory syncytial virus, rhinovirus –  that because of the way that these viruses spread are very similar, we would see very similar patterns and differentials in terms of the rates of infection in the community.

Obviously, the impact in terms of poor outcomes in relation to hospitalization and serious hospitalization associated with intensive care, and even mortality, are thankfully not as common in these other respiratory viral infections as they are for COVID-19. But the pattern of infections in terms of case numbers would be almost certainly be similar, but I don’t we discuss these inequities because there hasn’t been such a focus on examining these other viral respiratory infections by deprivation.

In the UK right now, we have very little capacity to test for other viral respiratory infections. What data we do have generally shows that social distancing and other public health measures to reduce the spread of coronavirus are also having a knock-on effect in terms of reducing spread for all these other viral respiratory infections.

What challenges are there when investigating health inequities?

One thing that has become clearer throughout the course of the pandemic is the challenge for estimating the total burden of disease to COVID. Early surveillance data tends to be around hospitalizations, intensive care admissions, and mortality. Underneath those serious outcomes, you have a much greater burden of disease for people who are being seen in general practice, people in the community with milder or even no symptoms who don’t have any interaction with health care systems.

Understanding burden of disease in the community for people that may have very mild or even asymptomatic disease is particularly problematic and in fact, we recently published a study with Wellcome Open Research that suggested that probably 1 in 3 cases of COVID-19 are actually asymptomatic.

Estimating the burden of disease in relation to cases that are mildly symptomatic or asymptomatic and don’t require any hospital admission is a real challenge, and it seems to be becoming clearer that some of the disparities that we see by ethnicity are really being driven by a higher infection risk in the community and the high rates of hospitalization we see by ethnicity likely reflects the much greater infection rates in the community.

What that means from a public health perspective, is that we do need to think about early access to care and good communication around how people navigate the health system whilst early in their course of disease. In particular, we also need to think about how we prevent more people getting infected in the community in the first place, because that’s the first point at which these inequities in viral respiratory infections start.

From a research point of view, we need to do more to understand ongoing community transmission, how to stop the spread, and then develop and deliver appropriate public health communications to help people take action, designing systems that can help prevent the spread and reduce inequalities and inequities in the community.

What impact could your research on this area have on reducing health inequities?

Since we published the paper there has been a lot more evidence emerge on community infection rates, and that increased risks in the community are something that leads to the really stark health inequities in hospitalization and death. Our research is also showing how important it is to design public health interventions from the start to reduce inequity.

An example of how public health intervention introduced inequities in the early stages of the pandemic can be seen with some of the testing and contact tracing systems. Early on in the pandemic, to be able to get a test, you often needed to have a car to be able to get to a testing centre that could be a substantial distance away from your place of residence. There were walk-in centres, but they were much rarer, even in London, and it was particularly challenging to get COVID tests at various points in time. A lack of easily available and locally available testing becomes a problem because, if you needed a car to drive 50 miles to get a test, that immediately means that your socioeconomic situation is going to determine access to a test and diagnosis. As a result, people in more deprived part of the country are going to get slower confirmation of their COVID status, which potentially penalizes them in terms of an early diagnosis and treatment, but also has knock-on effects in terms of the onward spread because if people are unaware of their diagnosis and it may mean that they are more likely to spread the infection to other family members, or people that they’re meeting with.

We need to consider this point when it comes to vaccination as a similar situation applies there, enabling easily accessible vaccination locations. I lead the UCL Virus Watch study, which includes just under 50,000 people across England and Wales. In December 2020 we asked people whether they were intending to get vaccinated, and we saw at that point in time over 80% of people over the age of 65 were intending to get vaccinated, with 20% of people either unsure or planning not to. We then repeated that survey in February 2021 and found that 4 out of 5 people who were either unsure or not planning to get vaccinated had changed their mind and had either been vaccinated or were planning to when their time came. We saw that, regardless of your ethnicity, 4 out of 5 people were planning to get vaccinated or had already been vaccinated if they had said that they were not planning to or were unsure in the past when we asked them in December. We should celebrate that success and we think it’s due to the very localized work that’s been going on to encourage and support people and provide good, clear public health information and advice about the vaccination. This is reflected in the fact that people were taking their time to understand the vaccination, including the risks and benefits, and the vast majority of people are saying yes when it comes to that turn to get vaccinated. But to capitalise on this important change in vaccine intension we need to ensure that vaccination is locally and easily accessible to everyone, and in particular those living in deprived areas where access to cars is more limited.

What is next for your research into health inequities?

There still is a lot of research questions that remain outstanding. We have been working hard with the UCL Virus Watch study to create a longitudinal that’s representative of the England and Wales population by ethnicity, by deprivation, by geography. We have broadly achieved that, and we now have over 25–30 weeks of follow-up on that community cohort.

The important research questions that we are going to be looking at over the next few months are around the inequities, because we think that, from a longer-term public health perspective, those are where the challenges will lie for COVID-19 and other conditions. How we tackle, understand and make clear and transparent those inequities as well as how we can design public health systems and communication strategies to avoid or minimize inequities are big focus points for the research going forward.

What role does open research have when exploring health inequities?

I am a very keen adopter of open research. I think it is important right from the start of a project in relation to defining and specifying research questions and outcomes and publishing these in protocols in order that people can understand any deviations that may or may not have occurred.

Open research continues to be important through to the data collection stages. What we have seen across the UK during the COVID pandemic is early and open data sharing and that’s really transformed the open research and data access landscape in the UK over the last 12 months and this has been partly driven by the urgency of the situation. I hope that this will continue after the summer when the urgency of the situation slows down.

The sharing of code, in addition to the data, is also extremely important because it enables other research groups to not only understand how you’ve tackled a problem and provides good transparency around analytical decisions. It can also help reduce and eliminate waste in research, but it also saves time for other researchers.

Do you have any final comments about health inequities for World Health Day 2021?

I think I would just like to reiterate the point that inequities in relation to infectious disease are a longstanding issue. It is an area where we need to do more, in relation to the transparency and the creation of evidence around the stark inequities that we see particularly for marginalized populations. Accompanied with that, I think, is the increasing importance and understanding that the delivery of interventions to reduce the spread of infection can actually exacerbate those inequities.

I would urge policymakers designing public health interventions to reduce infectious disease spread to think about those inequities from the start, to think about how communications can be clear and provided in a culturally sensitive way so that everyone can understand them, and so they are appropriate for everyone. Issues like access to testing, access to vaccination, thinking about those who may not have the socioeconomic circumstances to travel long distances and therefore may be unable to access vaccinations or tests should be built into the system. We should also consider how we can support people when they test positive for coronavirus, and whether they are able to self-isolate. Often, this can be very difficult because they could be working in precarious economic situations, and so providing economic support for that isolation is really important. People might also be living in overcrowded houses. If that’s the case, we should consider providing access to self-isolation facilities away from the home (for example, what Newnham Council have done recently) so that they are able to isolate from the rest of their family and reduce the onward spread within their family or household.

I’d like to see a much greater focus around reducing intervention-induced inequalities from the start – rather than just trying to solve the problem after it’s occurred.

Read the full Research Article via Wellcome Open Research, ‘Black, Asian and Minority Ethnic groups in England are at increased risk of death from COVID-19: indirect standardisation of NHS mortality data’ >>