How does housing affect our health?

Gretchen: Hello there, this is Prevention Works, the podcast of The Australian Prevention Partnership Centre. I’m Gretchen Miller, and today we’re looking at the intersection of a social determinant that is housing and chronic disease. Professor Rebecca Bentley is an epidemiologist from the University of Melbourne’s School of Population and Global Health. She’s also the director of the NHMRC Centre of Research Excellence in Healthy Housing, which is a member of the Prevention Centre’s CERI, the Collaboration for Enhanced Research Impact. Rebecca leads a research program exploring the role of housing and residential location in influencing health. It’s an extended interview today covering a lot of interesting ground, including the role housing plays in the Australian disease burden. We look at housing, asthma, and mental health, housing security, housing quality, and role models for rewriting the intersection of housing, urban design, and health policy. We also take a look at crisis housing and social housing and the Australian evidence that contributes to this work, but let’s start with the bigger picture. We’re talking here about the social determinants of health. Why, Rebecca, is that an important framework to consider when speaking of prevention?

Rebecca: So the social determinants of health are the non-medical factors that determine and shape population health and they’re absolutely critical to understand if we want to actually have prevention strategies that work in populations. They can be one of the biggest levers that we can pull to improve population health because they’re likely to affect a large number of people and they’re also likely to make a permanent change in the population. So in terms of best bets for prevention strategies in Australia, thinking about the social determinants of health is a really important way to go, but also the social determinants of health are the things that I guess moderate or allow us to access resources in our community, so they allow people to access the things that keep them healthy. So also, by thinking about prevention in terms of modifying the social determinants of health or acting on the social determinants of health, we’re empowering people to be able to access resources in their community and potentially improving equity in that access, so thinking about who is currently missing out and how we can make that more equitable. So the social-determinants-of-health perspective isn’t just about improving health, but it’s often about actually reducing disparities in health outcomes by improving equity for people in terms of access to resources.

Gretchen: Can I ask a personal question before we go on to talk specifically about housing, you’re an epidemiologist, Professor of epidemiology, what made you choose the social determinants as an area about which your clearly so passionate, how did you get here?

Rebecca: It’s a good question. So I began actually in psychology, so I did a Bachelor of Behavioural Science and was really interested in the things that can help people to have better mental health and wellbeing, but I think the more time I spent in that space the more I realised that focusing on individuals is one way to actually improve mental health and wellbeing, but if we pull back, I think, on a broader scale about what are some of the things that are shaping and affecting people throughout their lives and how if we’re able to address some of those factors we can actually have a big impact on a lot of people. So for me the appeal of moving from a discipline where I was focusing on individuals and individual outcomes to a broader population health perspective, and then to a perspective where I’m actually interested in the factors and access to resources in communities that are allowing people to lead their best lives and support and improve their health, was really appealing. I also think that the social determinants of health adds an element of complexity to the way that we’re thinking about our interventions that’s really important, so rather than simplifying down and thinking only about very specific pathways and thinking about to improve this aspect of someone’s health I’m going to offer them a medication or I’m going to help them maybe to run further every day or going to focus on something that’s actually quite specific, to me it just makes intuitive sense to look at the complexity of people’s lives and their everyday exposures and the structures around then that are shaping their everyday lives, thinking about how we can create healthy environments for people to live and work in so that they’re leading their best lives, for me that’s got a lot of appeal as a way to go in public health. It’s an enabling way to go, it increases health across populations in an equitable way, potentially, and also it just leads to better communities and better health, better society, the idea that we can all be healthier, that we can have equal access to resources and that our infrastructure is health infrastructure, so we’re enabling people to walk, to play, to eat well, to exercise, to be educated, to live in good quality housing, to do jobs that are meaningful, to earn a decent income, and to sort of have control over what they’re doing.

Gretchen: Wonderful answer, so interesting. So if we turn to housing now, how much of a role does housing play in Australia when we speak of Australia’s disease burden?

Rebecca: Yeah, this is a really interesting and good question and at the heart of what we’re trying to achieve in the Centre of Research Excellence in Healthy Housing. So we know that housing is a really important determinant of health, and that’s been known for a long time, and in Australia we don’t really know how the way that we provide housing is impacting directly on health, and that’s what we’re starting to try and understand and measure. So if we take something like asthma, for example, we know that people who live in mouldy homes are more likely to have their asthma exacerbated, and that the incidence of asthma might also be bigger, or people are more likely to get asthma when they’re living in mouldy homes, so there might be onset of asthma. But we actually don’t have a lot of information in Australia on how many homes have mould in them, how often this occurs, the severity of that mould, the distribution in the population, so to work out the actual burden of disease that living in unhealthy housing, and in this case living in mouldy housing might be causing, we actually need to do a lot better in measuring and understanding the state of our housing in Australia. So we’ve started doing that, we are doing a housing condition survey to understand that, we’re doing some prevalence surveys where we’re going out and asking people about mould in their homes and try to get a picture of that, and we’re also doing validation surveys where we’re actually measuring mould directly and comparing that to self-report, so we can start to understand that if people say they have mould in their homes is that a good evidence base to go forward on in terms of measuring up prevalence.

Gretchen: And that’s one element of housing issues, and it’s so important, isn’t it, when I know on the eastern seaboard we’ve had two La Niña in a row and we’ve had such wet weather that houses, certainly in Sydney where I am, the issue of mould is a very live one, it’s a live one for renters, it’s also a live one for people who own their own homes and there’s been this overwhelming incidence, I think, in Brisbane too, I’m not sure about Melbourne where you are, but it’s just like okay, this is something new that we’re going to have to deal with.

Rebecca: Absolutely. It’s important in a number of ways. So first of all, with our changing climate and changing weather patterns, we can expect a variation and possibly more mould in our homes due to increases in humidity, due to natural disasters causing flooding and damage to homes that creates moisture, and I think we’re starting to get a real sense of that in Australia that we’re actually quite vulnerable on that front. And in any case, Australia’s housing stock is, on the whole, we have issues maintaining indoor temperature in our homes, there can be structural problems in older homes that lead to issues around mould and rising damp and other things, and while we think that on the whole our housing stock is in quite good condition in Australia, we actually do have housing stock that was built in eras where there was more of a proneness or a likelihood of mould developing in some of our houses. This is something else we need to start to understand, what’s the particular nature of Australia’s housing stock and how is that actually contributing and generating health burden in Australia.

Gretchen: And it’s worth noting that a quarter of Australia’s disease burden is made up of cardiovascular, COPD, anxiety, depression, asthma, falls, and injury, that’s a quarter of our disease burden, so housing has an important role to play and is a significant element of our health burden. I mean one of the points that I don’t think we’ve covered already is the issue of housing security in particular, I mean you’ve alluded to it, one of the points is the issue of housing security, in particular, we know, for example, right now that there is very little out there to rent and we know that prices are increasing dramatically along with the cost of mortgages, so when we’re talking about housing are we talking about homelessness, are we talking about housing fragility, are we talking about affordability of mortgages, the pressure on the rental system in Australia as it stands at the moment, what are we talking about?

Rebecca: Look, essentially it’s all of those things but a way that I like to think about it is that we’re talking about housing affordability, which we see is really an apex determinant of health in that it directly impacts on health, but also, we know that people who are in unaffordable housing are probably less likely to maintain their property so that they might have a poorer condition dwelling in terms of having structural problems or they might not be able to heat or cool their housing, so through that pathway of housing condition we also see an impact on health. So housing affordability is a really important part of the story, and related to housing affordability is housing insecurity, so insecure housing is also associated with poorer mental health, and it’s associated with a range of issues as well in terms of where people then start to live impacting on their health in other ways. So for example, people who are in insecure housing might be less able to have a nutritious diet if we want to stick with public health and think about the consequences for people of the way that they’re living when they’ve got an insecure home environment, they might be much more stressed, they might be less likely to be doing exercise, they might be drinking more, they might be smoking more, so we know that that insecurity and that financial hardship that can be associated with either being in unaffordable homes or being in homes where people don’t have a sense of how long they’re going to be able to be there for or they’re not in the homes on their own terms is actually a really stressful experience. In terms of homelessness, which is also a really important health issue, that clearly contributes a lot to burden of disease as well and the pathways there are quite different, so housing insecurity is associated with or generates homelessness, the time spent in a homeless situation, whether that be rough sleeping or through living long periods of time with an insecure housing arrangement, going from tents to cars, sleeping on people’s sofas, there’s lots of ways in which that negatively impacts.

Gretchen: And there’s some really interesting points about the way that we’ve built homes in Australia up until now. Even issues such as dark roofs versus light roofs that will have literally a health effect on people as we see increasing temperatures.

Rebecca: So  just to tie that back to in our question that you asked previously about do we have a sense of the scale of the problem, some early work that we’d done in our Centre where we tried to model the hypothetical scenario of if we could get rid of all cold housing in Australia what would be the benefit to population health, and what we found in that preliminary work is that it’s actually quite a significant benefit that actually eradication of cold housing in Australia can have a similar effect to more medical interventions in terms of improving something like cardiovascular disease, but also we could be saving a lot in terms of the healthcare system, so we estimate at least or on average about $1.9 billion in savings to the healthcare systems if we were to eradicate cold housing in Australia, which is quite a substantial amount of money, and that’s just one pathway, so that’s just looking at cold housing through to a range of health outcomes. If we think about, in addition to that, things like mould in homes and we think about other aspects of housing that can be unhealthy, for example, housing that might cause injury risk or exposure to sort of noise or toxins, then there is actually a significant burden sitting out there that we do need to understand if we want to have good prevention strategies around it.

Gretchen: But there’s also mental health, could you talk about how housing impacts on mental health?

Rebecca: Yeah look, mental health is really interesting. So, for example, one of the findings we didn’t expect from our modelling work on cold housing is that one of the pathways that leads to the biggest, I guess, burden of disease generated from cold housing is through mental health, so that if we were actually to eradicate cold housing the pathway through to mental health is one of the stronger levers that would be pulled and we would actually have a population-level improvement in mental health.

Gretchen: What about hot housing, because heat is also a massive issue, is it the same effect or is it different?

Rebecca: Yeah look, so in terms of the effect on mental health both hot and cold housing have an impact on mental health. The pathways might be slightly different but there’s also some shared pathways there, which is about living in an environment that’s unpleasant, and potentially living in an environment where you can’t have a good sense of community because it’s either too cold or too hot to be in comfortably with other people. Generally, being in hot or cold housing is also associated with some kind of financial hardship or energy poverty so that you’re not able to cool or heat your house because you can’t afford to run the air conditioner or the heater, so there’s certainly some shared pathways which negatively impact people’s mental health and wellbeing. But there’s also some differences there, so for something like hot housing it’s much more likely to negatively impact on people’s cardiovascular health in the sense that they might end up with an emergency admission due to just the overwhelming nature of the heat affecting their cardiovascular system, whereas cold housing does also affect cardiovascular health but through changing blood pressure and a much sort of longer process. So the pathways are interesting and different and we need to understand them more and really part of what we’re trying to do with our modelling is understand each of these pathways and put a quantitative assessment on how much the contribution of housing is making to our poor health in Australia so that we can really build this into our prevention strategies.

Gretchen: As I was researching your work, I noted that nutrition was an issue in housing in security, so I wonder how housing can influence nutrition, which of course has a major influence on many of our chronic diseases, like obesity and heart disease and even anxiety and mental health?

Rebecca: Yeah, so good question, and I think there’s a lot of pathways through which housing has an impact on nutrition. First and foremost is the location of the housing and that maybe less to do with the house itself but where people are located in Australia does determine their access to healthy food. We know that some communities that are quite isolated do have difficulty getting access to fruit and vegetables. But if we think just about the housing itself, issues like whether people are in secure housing and have access to refrigeration and cooking, that can impact their ability to have a healthy diet. If people are in parts of Australia where there is heatwaves and issues with the constancy of their electricity supply that can also impact on their ability to heat and cool food. The other pathway that’s really important though is that for people who experience financial hardship because of their high housing costs or any kind of insecurity around their housing, they’re just perhaps not able to afford a healthy diet or they’re very stressed, and their focus isn’t on their nutrition and it’s on other aspects of their lives and they might not be eating healthy diets. So I think it’s a really interesting question. I think the other thing to think about in terms of prevention is that if we focus on improving housing quality, and if we’re able to, say, guarantee that people are able to have a kind of kitchen where they can cook healthy meals, that they’re able to have an electricity supply that meant that they could keep not just their food but food and medications at the right temperature then that could be a really important prevention strategy. So while we’re improving people’s wellbeing and quality of life and reducing their cardiovascular risk and reducing their risk of respiratory illness and contributing to better mental health, we might also be improving their nutrition through these other pathways. So to go back to your question of why housing is such an important determinant of health, it’s right there, the fact that there are so many ways in which housing influences the way that we’re able to live our lives to their maximum in terms of being healthy, then it’s actually quite an important mechanism or lever that we can use in Australia to improve population health.

Gretchen: So shall we zoom out a little now, what other high-income countries have successful used housing to reduce their burden of disease?

Rebecca: My favourite example is what’s happening over the ditch in New Zealand. So New Zealand has for a long time been very proactive in the space of healthy housing, their researchers have really strong relationships with policy in New Zealand, or policy making in New Zealand, and they’re at a point now where health policy has housing embedded in it. So, for example, there’s a Warrant of Fitness test that landlords can use on their properties to make sure that they’re adequate for people to live in and will support their health.

Gretchen: Can use or must use?

Rebecca: It’s can use in most parts of New Zealand, so it’s an opt-in option, but a lot of landlords are taking it up. There’s also subsidies for low-income people to improve their housing, so they can actually get subsidies from the government to do retrofitting to make their homes warm and safe and secure, and that’s also another really important initiative that we’re seeing in a country like New Zealand that actually is proving to have a fairly significant health impact, so we’re seeing less hospital admissions, less missed days of school, and we’re just seeing better health in the people who are able to make these modifications to their homes. In other ways we know that the provision of public or social housing is a really important way in which we can provide protection to people who may be in trouble but also just to provide healthier housing to people, and there’s many countries where 25 to 30 per cent of the country’s housing stock might be made up of social housing, and a lot of people will go through their lives and at some point use social housing. So, for example, when there are students studying at university they might spend a period of time in social housing. We’ve got a very different picture in Australia, so our social housing rate is quite low, or the amount of social housing stock we have is very low, around 4 or 5 percent, and what that means is that it’s essentially performing a welfare role and even then there’s a lot of people on the waiting list for that housing.

Gretchen: And the housing is frequently in an absolutely appalling condition. What other alternatives are there to providing a welfare role, what other ways could social housing… because we just assume that it’s a welfare thing now?

Rebecca: We make that assumption in Australia and it’s not the case in every country. So as I said, countries where it’s a much more integrated part of community and maybe people, you could think about as people’s housing careers, they might spend a period of time in social housing at particular parts of their life, there’s not a stigma associated with that, it’s just a way that that particular country’s government is providing housing to the population, and it’s  based on, I guess, an assumption or premise that housing is really important, that actually we need to get housing right and be able to provide citizens with a reasonably good quality of housing for other things to happen. I think in Australia we could do better on that front, and there’s lots of people making that case, at the moment, politically. There’s also been a reasonable amount of money, so I live in the state of Victoria and there’s a big housing build on at the moment and a lot of money is going into social housing in Victoria, but really, given the dire state of our social housing sector it’s actually just bringing us up a bit, it’s not actually going to take us into a place where we’re matching what’s happening in some other countries. So I guess in response to your question of other countries doing it better I think countries that have a much more supported and bigger social housing sector are doing better, and I think countries where we have healthy housing embedded into housing policy and health policy in an integrated way are also doing better.

Gretchen: Can you give me some examples of the former? Where else are we seeing housing done well?

Rebecca: Yeah, okay, so again, I guess I’d pull out a lot of examples from Scandinavian countries and Germany, the Netherlands, where there is a much stronger history of social housing being a part of housing stock, and where the standards around rentals and housing are higher, and also where there’s a little bit more protection for people in terms of experiencing insecure or unaffordable housing. So people who acquire housing for short-to-medium parts of their lives are able to access that much more easily in those settings. They also do tend to have much more explicit consideration of health in terms of their homes, so the way that homes are designed has more thought given to the health aspects of it than we might see in Australia where really, housing has become a way to make money and an investment, and we’ve probably lost sight of the way that we should be also thinking about housing as an important setting for health, an important setting for the way that people live their lives.

Gretchen: So you’re leading a research program exploring the role of housing and residential location in influencing health, one of the ongoing issues for the way Australia manages its health burden is, a criticism has been a lack of interdisciplinary engagement, what disciplines are you bringing to your research, who else are you drawing into your work?

Rebecca: Yeah, so it’s an interesting one. I think part of the appeal of working in the space of healthy housing for me is working with a range of disciplines, so getting outside of the health space and talking to urban planners, talking to geographers, talking to people with deep expertise in housing and the housing system, so housing economists, people who provide community and public housing, those providers actually have a lot of knowledge of housing and the housing system in Australia, so in our research group itself we’re bringing together a combination of epidemiologists and modellers, because we’re very clear that we want to be able to model the health benefits of any housing interventions that are put in place in Australia, but also demonstrate their potential. We have geographers, so we have Professor Emma Baker who is a human geographer bringing deep expertise in housing. We also have people that are really knowledgeable around housing policy, so Professor Andrew Beer is an example of that, he’s very interested in regional housing and regional issues around housing. We also have a group of researchers who are focused primarily on Aboriginal health in Australia, and keen to develop a stronger agenda around modelling the benefits of improving housing for Aboriginal communities in Australia, particularly in the face of climate change where we’re looking, if we take northern Australia as an example, at some fairly significant increases in temperature in those parts of Australia, and there are also parts of Australia where we currently don’t have very good quality housing stock, so structurally there are houses in that part of Australia that you can’t put solar panels on because the structure of the house is so poor that it can’t take them. So thinking through some of those issues, thinking about how we provide housing into the future for those kinds of communities is really important. So those collaborators are bringing a really strong community focus and really trying to help us understand how we can be community led in the way that we’re thinking about our housing research.

Gretchen: So have you got members of the community and members who are actually working on the coal face with provision of housing as part of your team, or policy makers, for example?

Rebecca: It’s probably more that what we have is a translation advisory committee, and on that translation advisory committee we have strong representation from policy folk in Australia who are quite critical to providing housing. It’s chaired by the Director of the Australian Housing and Urban Research Institute, Dr Michael Fotheringham, and we have on that panel philanthropy represented, people who are working in the private rental sector policy area, and also we have people who are interested in health and health promotion, we’re trying to sort of bring all of that together in that setting to, I guess, really set an agenda that can feed into government. So we know, for example, that Australia has just recently launched its prevention strategy, which is a very good document, and one of the highlights in that document is that they want to take a systems approach to understanding prevention in Australia. Now understanding the housing system, particularly in relation to tenure and how we rent housing in Australia in both the private sector and the public sector in a systems way is actually a potentially nuanced and complex but really important way in which we can start to use housing more effectively as a health lever in Australia. So if we were able to generate through our housing system better opportunities for people to access affordable housing, access secure housing, access housing in a timely way once they experience a disaster or have some sort of crisis in their lives, then we would actually have a very significant positive impact on health through a lot of pathways including mental health and wellbeing.

Gretchen: And we’re certainly seeing how critical that is right now with, well, it was two years ago, we’ve still got people living in temporary accommodation after bushfires, we’ve got the floods with people dislocated because of that, so we really are starting to see just how pointy this is. When you’re drawing on the work of geographers like Professor Emma Baker, for example, when you look at Australia’s housing policy is health currently a part of that policy?

Rebecca: It’s interesting. It is and it isn’t. So we’ve actually done a bit of scoping of Australia’s health policy documents to see do they mention housing and if they do what are they saying, and what we find is there’s often sentences in some of our policy documents about the importance of the social determinants of health and housing is often named as one of those important determinants, and we see it referred to but we don’t see very specific detail on that and we also don’t see a lot of very specific policies in the health domain relating to that, and we’re really hoping to see that change. Housing is also mentioned a lot in relation to ageing and ageing at home, so healthy housing in Australia in relation to older people is certainly something that we see in policy or being addressed in policy, and also in terms of Aboriginal housing, there is policy now that’s being developed, sort of historically but also now, trying to provide better housing in that sector, and so we do see that a lot in policy as well. But in a more general way in terms of policy acting across the whole of the housing sector, so from ownership to private rental to public rental and also housing being really embedded in a prevention strategy in Australia beyond identifying it as a social determinant of health or identifying social housing as something that we should be providing more of in Australia, we actually don’t see a lot of crossover in terms of housing entering into our health policy.

Gretchen: Rebecca, we weren’t always this terrible at integrating the various factors that contribute to health, I think that in the past we were much better at factoring health into urban design, for example.

Rebecca: Yeah look, it’s an interesting thing. I guess there was a time in Australia where, around the 1970s, the supply of social housing, or public housing as it was known at that time, it was much more available, it was built in a lot regional areas in Australia, it was built in places where we needed a workforce, so it was providing homes for people so that they could live better lives, and there were states in Australia where the provision of public housing was up around 20 per cent, and so it was much more part of the way the government thought about providing infrastructure to people that enabled them to work and enabled them to live good and healthy lives, and I think really, we look back on that time now and it’s almost hard to believe. So in Australia today, as I said, we see housing much more as an investment, our rates of social housing or the amount of social housing stock we have is very low, we have long waiting lists for social housing, we have a housing affordability crisis in regional Australia where people can’t live where they work, and all of these things have become highly problematic for government to try and solve, they’re quite complex problems, but I think it’s interesting that if we go back in time and maybe not all that long ago we were actually travelling a lot better in this space.

Gretchen: So we could draw on our own history, actually, to improve things. So a critical point that you’ve made though is that there has been an inadvertent, almost, improvement in health through housing interventions, could you clarify that?

Rebecca: I think what I meant there is that when we do make improvements to our housing, either through supporting sustainable design, giving people the opportunity to put solar panels on their roofs, maybe through a government subsidy, insulation in homes, providing people with the ability to double glaze, all of those things maybe are part of the conversation that we have in terms of planning and our building code in Australia, but we might not be explicitly thinking about that as a health intervention, and I guess the change that we’re wanting to make is in our CRE, in our Centre for Research Excellence, is to start to understand how some of that activity that’s happening outside of health, so it’s happening in the way that we set up our building code in Australia, in the way that we plan our cities, in the way that we provide subsidies for people to improve the quality of their home in terms of, for example, solar panels and being more sustainable, that those things all have a health benefit, and if we can actually capture some of that and quantify some of that then we can really begin to understand how important these relationships are, which might give us some sort of momentum to think more broadly about how we can be using housing in a much more effective way to improve population health in Australia across the dimensions that I’ve mentioned, so across that sort of dimension of improving housing condition, but also the importance of affordability and security and some of those other aspects of housing that will also have a health benefit.

Gretchen: Okay. We touched on it briefly just before, the ways that health and housing intersect, like disaster planning, for example, as we’re seeing in flood-stricken areas right now, given that it seems to be taking quite a while for solutions to be developed there have you had any input into that?

Rebecca: Yeah, I haven’t had any input into that but I’ve certainly had some thoughts on that. So, as I said, for me watching what’s happened as a result of the Lismore floods to people who have lost their housing or become insecure in terms of their housing, has really reinforced for me the importance of having a housing system that, I guess, understands and appreciates how housing can protect people’s health and is able to operate effectively in those times of crisis for Australians which are actually going to increase over time in terms of frequency and intensity.

Gretchen: And do you think that those learnings for places like Lismore and the south coast of New South Wales might also inform some of the ways or might also change the ways that we think about the housing crisis in remote, Indigenous communities?

Rebecca: Yeah, so again, there’s a couple of things that are happening there and one is that we’re starting to shift our thinking and see, look, it’s not just about generating income here, housing is actually really important, it plays a really important social role, plays a really important role in protecting people in Australia.

Gretchen: It’s a critical role. So wellbeing on so many levels as we’re talking about here.

Rebecca: Yeah, and that we, I guess, by not appreciating that or regarding that we are providing substandard housing to a lot of people in Australia who are vulnerable, so including populations in the Northern Territory and now people who have experienced flooding in northern New South Wales and in Queensland, and people in Victoria who have experienced bushfires, so similarly, there’s lots of communities there where there’s still dislocated people. Some work that we’ve done where we’ve tried to look over time at people’s recovery from natural disasters to see how their housing might enable or protect that recovery, we certainly notice that when there’s any housing vulnerability at the time that people experience a natural disaster, so a flood or a bushfire, that the recovery in terms of their mental health and wellbeing and their recovery in terms of other aspects of their lives, including where they end up being housed is actually a lot slower, it can be years and years more recovery time when people are coming from a place where they’ve got some kind of vulnerability in their housing. So again, just by going back to prevention, just by having people housed in a secure, good way to begin with, we’re actually potentially down the track avoiding some of the problems that we’re going to see with increasing disasters or at least helping people to recover better from those experiences because they’re coming from a better base in terms of their housing.

Gretchen: To date it seems there’s been a real dearth of Australian-specific evidence, causally focused evidence, but you’re working on this, where are you up to?

Rebecca: Yes, so what we’re doing is really trying to be quite systematic and think about where it’s most important to have Australian-specific evidence and start to actually collect that now and feed that into the research that we’re doing. So, for example, we know that Australia’s housing system is quite different to the housing system in other countries, in European countries, and we also know that a lot of the evidence on healthy housing that’s used by organisations like the World Health Organization comes from European studies and not Australian studies. So we need to know in our Australian housing system what the mix is of poor-quality housing in rental and how long that might take to fix, and what people who are renters are able to do in our system in terms of negotiating with landlords around some of those issues. They’re all issues that are actually quite specific to our housing system. So we need to understand those but the other important aspect as you’ve mentioned is that we want to know about causal evidence, so we don’t just want to know whether being in a terrible house has an impact on your health, we actually want to know what some of those specific causal pathways are. So if you experience a certain period of time living in housing that is cold, for example, what is the size of the impact of that through to your cardiovascular health, your respiratory health, and your mental health? Now, why is that important? It’s important because we need to know in terms of intervening on those pathways and also trying to work out the actual total size of the negative effect that housing is having on our health if we want to actually make a case for addressing it, start having housing embedded into the way that we provide health policy in Australia, and the other, I think, really important opportunity that we have in Australia is to think about how we can use housing as part of a social prescribing agenda. So if we understand, for example, how much the risk of asthma could be reduced in Australia by addressing someone’s housing situation, and we know that that evidence is causal, then we can start to build that into the way that we’re treating people who arrive in emergency with asthma or are visiting their GP with asthma, we might want to think, for example, in addition to prescribing medications or admitting them to hospital, of doing an assessment of their home environments, and seeing what we can change about those environments that might mean that in the future they don’t end up in emergency or in a healthcare setting needing medication because their asthma is being triggered by something that’s happening in their home environments.

Gretchen: Something like asthma is fairly immediate but cardiovascular problems are not, so I think what complicates this, right, is the time-based lag, housing doesn’t affect health generally speaking in a way that you can quickly and overtly identify as causal.

Rebecca: Yeah, exactly, and that’s why it’s hard in this field of research to go out and do a trial where we randomise people and watch them over time and see what happens to their health. We can if we’ve got a short-term kind of impact on health but if you’re looking over the longer term it’s harder to pick up with that kind of study design, and there’s certainly ethical issues with randomising people in poor-quality housing. So yeah, you’re right, exactly, that for a lot of the things that are actually quite important we actually need to move to other ways of understanding that, and that can be by doing things like using simulation modelling in populations to try and see what the benefits would be in 10 years’ time, 20 years’ time, or over a lifetime in improving people’s housing conditions now.

Gretchen: Yes, I was going to ask how therefore you would model these impacts for policy makers.

Rebecca: So there’s a number of ways that we can do this. In our Centre we’ve set up a data infrastructure where we use information on the prevalence of exposure to certain conditions, we gather as much information we can on the causal relationships and the relative increased risk that people might experience if they’re exposed to poor-quality housing, and then we put those essentially into a series of models where we simulate in a cohort or a population over time how that might reduce the health burden based on those parameters. What we’re also able to do in those models, probably innovatively and perhaps for the first time internationally, is also take into account who benefits the most. So we look across the income strata and see whether our policy, so, for example, in the case of eradicating cold housing what sort of reduction in health inequities we would get by using or employing an intervention that eradicated cold housing in Australia. So we’re interested in the total health gain over time but also in that inequality reduction. So the way that we’re going about this modelling is we’re using causal evidence, we’re using Australian-specific evidence, we’re taking equity into account in the way that we’re modelling it through, and we’re interested in the savings to the healthcare system that could be achieved through housing interventions.

Gretchen: Look, I think that’s been a really fascinating and quite comprehensive conversation which I’ve enjoyed tremendously. Thank you so much Professor Rebecca Bentley for your time here on Prevention Works, from The Australian Prevention Partnership Centre, and there will be of course more information and links on our website. I’m Gretchen Miller and I’ll see you next time.