Are we missing the bigger picture in rheumatic and musculoskeletal diseases? The syndemic perspective

Recognizing these overlaps ultimately helped clinicians design more integrated and effective strategies for HIV care. So, what if we applied this approach to rheumatic and musculoskeletal diseases? Could looking at biology alongside social determinants help us better understand disease, improve patient care, and ultimately advance health equity around the world?

To explore this, I’m joined by not one but two brilliant clinicians working at the very forefront of this space: Dr Elena Nikiphorou, a Consultant Rheumatologist at King’s College London, who first introduced the concept of syndemics in inflammatory arthritis, and Dr Lisa Hamzah, a leading HIV consultant at St George’s Hospital, London, with a strong interest in syndemics, bringing valuable insight into how HIV care has shaped syndemic thinking.

Gina: Welcome to you both, and thanks for joining us today. We’re so excited to have you with us.

Elena: Thank you very much for having us.

Lisa: Yes, thank you indeed.

Gina: It’s our pleasure. I’m really looking forward to having two guests, it’s not usual for us! Today, we’re going to talk about syndemics. And, Elena, I know this is something you’re very passionate about.

Elena: That’s true. It’s been a topic that I’ve been working on in the last few years, so I’m really, really keen to engage in this discussion with you.

Gina: Lisa, it’s also lovely to have you with us as well.

Lisa: Well, thank you for inviting me. You know, I was reflecting on syndemics when you invited me to this podcast, and I was thinking… I think this is the reason I actually chose my specialty in HIV because I just find working with social determinants of health and the impact that they have on health just so interesting. So, thank you very much for inviting me today.

Gina: My pleasure. So, we’re going to start today with health inequities. It’s a word we often hear when we’re talking about syndemics. Lisa, could you explain what we mean by that term?

Lisa: Of course. So actually, there are many proposed definitions of health inequities, but I really like the WHO definition from 1990. It describes social inequities as these systemic differences in health statuses between different social and economic groups. I like this definition because firstly, it uses good health as the outcome, and it points out that these differences in outcomes are actually because of societal and structural differences, and that equates to about one death every ten minutes, which I think is incredibly striking. And you see this gradient going from the least to the most deprived. You can do this with pretty much any health outcome, and you’ll get exactly the same answer. But what I thought was really interesting is that although only a tiny proportion of these deaths were due to infection, for example, HIV, tuberculosis, hepatitis, actually the greatest inequality was observed for those deaths. For example, the mortality attributable to socioeconomic inequalities was 80% for TB and 75% for HIV, which I thought was really, really interesting.

Gina: From what I’ve read around the topic for our conversation today, it seems widely accepted that social determinants of health are responsible for significant levels of health inequity. What are social determinants of health, Lisa?

Lisa: So, they’re the nonmedical factors that influence our health outcomes. There is another WHO definition, actually, which defines them as the conditions that people are born, grow, live, work, and age in, but critically also about people’s access to power, money, and resources. They include things that you would expect such as income, education, employment, food security, housing, and discrimination. We also know that individuals living with HIV, in particular, experience a disproportionate level of these intersecting social disadvantages, such as lower socioeconomic status, structural racism, and HIV-related stigma. To give you an example, the most recent Positive Voices survey, which was a very large survey in England that surveyed one in twenty people living with HIV, showed that overall, 43% had an unmet social need, and almost half didn’t have enough money to meet basic needs. It also showed that people living with HIV were three times more likely to be in temporary accommodation, twice as likely to be unemployed, and ten times more likely to have been in prison. In fact, in a recent study that Elena and I worked on in south London, in a cohort of almost 400 people of black ethnicity with HIV, 72% had at least one other comorbidity in addition to HIV. We found a really high prevalence of socioeconomic deprivation, with around 85% reporting at least one adverse social determinant of health. And there’s actually very good research to show that these poor social determinants of health adversely affect every level along the treatment cascade in HIV, from HIV prevention, to being on treatment, to staying in care, to taking your treatment, and overall well-being.

Gina: What do we see in terms of RMDs, Elena?

Elena: Very similar to what Lisa has said, and actually, it’s not just across RMDs; I think it’s across many diseases, especially the more chronic diseases. For example, we know there’s research that shows that patients in self-employment or in a low wage job tend to miss appointments, leading to missed treatments. Their adherence to medication may be less. We see this also with lower education and lower health literacy, which are important when it comes to social determinants of health. They have been linked with poorer outcomes in our patients with rheumatic diseases. But even if you take, for example, areas around access to healthcare, we know that patients living in rural areas may wait longer to see a rheumatologist; therefore, there are delays in diagnosis, in treatment, in starting therapy, which is so crucial in the case of rheumatic diseases. And of course, there are other factors like cultural beliefs and language barriers which come into this. And again, they link with lower education, potentially with lower health literacy. So, they really manifest in all sorts of ways. Social support is another example. If I was to reflect on an example, Lisa, you’ve mentioned one that we’ve been working on together, there’s another one in the world of axial spondyloarthritis, where we looked at five year data from a French cohort. This is an early axial spondyloarthritis cohort of young working age individuals, and there we saw that patients with older age and higher disease activity were associated with higher hazards of sick leave. And again, this was a finding that suggested the important role of these socioeconomic factors in adverse outcomes, including work outcomes, in these patients.

Gina: How well are these factors studied in the traditional research that we see today?

Lisa: In my mind, traditional epidemiological research obviously focuses on the influence of variables, so exposures of interest, on designated outcomes. And even when exploring the impact of social determinants of health on, say, HIV or rheumatological outcomes, it’s really limited to looking for confounders between exposures and the outcomes. It doesn’t really take into account the interaction between the disease and the social determinants of health, and I think it becomes really hard not just to untangle the disease pathways but also to measure and quantify the effects they’re having on each other. I think a lot of the traditional epidemiological research really only focuses on a few of the social determinants of health. For example, somebody might choose food poverty or housing and doesn’t really take into account these multiple intersecting factors like stigma, discrimination, or isolation.

Elena: Absolutely. And I think what you’re saying there is that traditional epidemiological research lacks that granularity that’s necessary to adequately capture these important factors. It tends to be more focused on biomedical risk factors, and there’s a very limited or simplistic approach when it comes to studying the social determinants of health, such as education and work status. They’re very crudely measured in traditional epidemiological research. And again, you mentioned this sort of lack of intersectional analysis, taking into account all these factors, both the biological and the nonbiological, which is where frameworks like syndemic ones come into the picture, and they bring that sort of relevance along.

The other issue, I think, is the underrepresentation of certain populations, which are very difficult to capture in traditional epidemiological research, but they are the groups of people that should be targeted when it comes to better understanding the impact of social determinants of health on outcomes. So, if I was to sort of round this up, I would say that traditional epidemiological research is of course great, but we do need other ways of studying all these different but important parameters together under the same framework. We need more holistic, inclusive, and socially aware, if I may say, research methods that are sensitive enough to capture this detail that we are looking for. I suppose this is where the concept of syndemics comes in, and how we could better perform the research to capture this.

Gina: How does the concept of syndemics help us better understand chronic diseases like inflammatory arthritis or HIV?

Elena: It’s really, really important. We have definitely learned a lot from the research that has been done to date in HIV. When we first made reference to syndemics in the context of inflammatory arthritis a few years ago, we were largely inspired by the model that was used in HIV, and this was because of the realisation that single disease frameworks are not fit for today’s complex healthcare needs in our patients. We do need these more integrated and patient centred models to truly improve outcomes and equity. This is where the role of a syndemic approach comes into the picture. It helps us to account for multiple morbidity, which is a common problem in rheumatic diseases and HIV as well, and it allows us to better acknowledge the relevance of social determinants of health.

Gina: How did this concept of syndemic research originate, and what did we learn from it?

Lisa: It was actually first coined by a researcher named Merrill Singer way back in 1984. He noticed that substance use, violence, and increased HIV risk frequently occurred together, and he called this the SAVA syndemic. It was from here that the context of syndemics first arose. You really need two main factors for a syndemic. First, you’ve got diseases that are all clustering together in time or place due to poor social determinants of health, but also that the diseases and the social determinants of health interact using biological, psychological, and social pathways. So, for example, in the population that Singer was studying, the effects of drug use could lead to violent behaviours. Violent sexual behaviours are associated with increased risk of HIV, and the trauma from violence often promotes increased drug use. And so, you can see here that the key is really the synergy between these factors so that the adverse combined outcomes are greater than just the sum of all these independent events, in this case, both diseases and the social determinants of health.

Gina: Are there any parallels between the syndemics that we see in HIV and what we’re now learning in inflammatory arthritis?

Elena: Absolutely. There’s a lot of common ground. Lisa, you’ve mentioned synergies and complex interactions. These are so relevant also in the context of rheumatic and musculoskeletal diseases. We know that both diseases, HIV and rheumatic diseases, are associated with morbidity, for example, and this is again where a syndemic kind of approach helps us to understand those complex interactions between different diseases, but also with social nonbiological factors that potentially drive these adverse interactions. For example, we see in rheumatic diseases, as in HIV, disparities in diagnoses, in access to care, and in access to biologic drugs. There’s also the stigma of chronic pain and disability. In rheumatic diseases, we also have the issue of invisible symptoms. So, patients with lupus, for example, report pain and fatigue, but these symptoms cannot be visibly seen. This again comes with a lot of complexity and stigmatisation. There is also, as in HIV, a need for this integrated approach to care, a more holistic approach. The parallel in rheumatology is that we can certainly learn and adopt this health equity lens seen with HIV and the global efforts that we do see in the context of HIV. We can see differently in rheumatic diseases and use it to better patient outcomes and improve the care that we give.

Gina: How can syndemic-informed research and care models improve outcomes for patients?

Lisa: I think syndemic-informed research is so important because, as a conceptual lens, it just really helps to widen that focus and really appreciate how you just can’t examine a disease pathway in isolation or address one aspect of somebody’s life. I also really like the way it brings social determinants of health as being central to health outcomes. I think that has been really lacking in previous research.

Elena: I agree entirely, Lisa. I think it’s similar in rheumatology, I think it is a way of accounting for all potential sources of inequity that address the entire journey of the patient, from risk prediction (for the development of disease) all the way to diagnosis, the care received, and an approach that helps us to address multimorbidity, that prevents fragmentation in care, and enables that more personalised, person centred approach to care, which is really what we should all be striving for.

Gina: When it comes to one change you’d like to see in clinical care or policy based on the idea of syndemics, what would that be for you, Lisa?

Lisa: I actually think it’s the real appreciation and recognition of how important social determinants of health are, and that we really meaningfully need to invest in people’s lives from birth to death, and to lift millions of people out of poverty across the world, not just to allow them to achieve a happy and healthy life, but ultimately to save money in healthcare.

Elena: I entirely agree and want to repeat all that. It’s very, very relevant in rheumatic diseases as well, and I think it would be really lovely to continue to work towards improving and encouraging a more integrated and holistic approach to care, which enables us as clinicians to tailor our management according to those individual patient needs. All of these should be part of our attempts to maximise care and improve patient outcomes and ultimately, of course, quality of life.

Lisa: I absolutely agree with you. And I think working within HIV, we’ve actually long appreciated, even though we didn’t always have the research tools and the terminology to describe it, how important it is to address those social determinants of health. Even at a clinic level, we offer peer support, housing benefit advice, counselling, psychology, and well-being because we know that it’s associated with better health outcomes. As you’ve said, people who are really struggling with paying the bills, finding somewhere to live, or looking after their children, they’re going to really struggle to achieve that 100% adherence to daily medication that they need to control the HIV virus.

Elena: Yes, and especially as we have all this research that tells us, shows us, very clearly that these disparities lead to avoidable suffering. They lead to poorer outcomes, and they lead to higher healthcare costs. It’s an absolute must that we address them in order to achieve more equity in rheumatology and in HIV care.

Lisa: I’d actually like this to be the blueprint for all long term conditions because it’s really addressing the key aspects that are helping keep people well and happy in their lives.

Elena: Absolutely. I think we’re getting really passionate about this, and I think maybe an important message to share with other clinician colleagues out there is that we have a duty, it’s an ethical and professional duty, actually, to ensure that the clinical care we give is fair, effective, and human in the simplest way.

Gina: For those working in the field of RMDs and who have heard our conversation today and perhaps want to learn a bit more, Elena, what should they do?

Elena: If you’re interested to hear more about syndemics in the context of rheumatic and musculoskeletal diseases, please take a look at the link below. We do have an international consortium, it’s a European Alliance of Associations for Rheumatology (EULAR) study group that invests time and energy into the study of syndemics in RMDs. So, please do have a look and reach out if you are interested.

Gina: Well, that’s it for today. Thank you both for joining us. It’s given us a lot to reflect on and probably shed a light on a topic that many definitely wanted to know more about.

Elena/Lisa: Thank you for having us.

Gina: Now, before you go, if you’ve enjoyed today’s episode, please do subscribe. And don’t forget, you can now find us on Spotify, Amazon Music, and also Apple Podcasts.