We've often talked about social determinants of health on Healthcare Triage. That's because they have an enormous impact on health. But, while we're willing to spend enormous amounts of money on things like drugs and procedures that might make small contributions to an individual's health, we are often resistant to paying for big things that matter, like housing. This is in spite of the fact that housing can often have a huge impact on health.

Over the next few weeks, we're going to be making our fourth deep dive into health policy issues, especially those that touch on social determinants of health and health equity, thanks to the support of the Robert Wood Johnson Foundation. 

We're going to talk about housing. Today, we're going to talk about why that's important to health. That's the topic of this week's Healthcare Triage.

[Intro]

Here's one of the biggest issues when it comes to affordable housing: It's much easier for landlords to make money from renting high-cost housing than low-cost housing. This isn't an easy problem to fix. It can take time and money to get through the permitting process to build, and that raises costs. Zoning requirements can restrict the number of units in a building, or how small they can get. There's also the NIMBY effect (Not in my backyard), where community members actively resist the construction of low-income housing nearby, because they fear that this will lower their property values or bring an increase in crime.

The situation's worsening. Wages have been pretty flat for a long time, but the price of housing has not been. There's much more demand than supply. Between 2005 and 2015, the share of renters whose rent constituted at least 30% of their income went from 45 to 48 percent. The share of low-income renters who had to pay at least 30% of their income in rent went up 24%, from 18 million to more than 23 million households. But, the share receiving assistance dropped.

Depending upon where you live, affordability can vary greatly. In plenty of places across the country, even a very low income household might be severely cost-burdened. This means that a household with an income no more than 30% of the AMI might have to pay more than half their income on housing costs. This leaves very, very little for other things, like food or heat.

But, before we talk about fixing problems, it's important to understand why housing is important for health. In the summer of 2018, Health Affairs published a number of briefs written by experts on housing. We're going to lean on them heavily in these episodes. 

The first of them, which is an overview of the literature, was written by Lauren Taylor, a doctoral candidate at the Harvard Business School. She describes four pathways by which housing affects health. Stability, quality and safety, affordability, and neighborhood. Let's dive into each.

The stability pathway refers to people who fall behind on their rent, need to move frequently, or are living temporarily in others' housing. Basically, we're talking about people who face housing instability. Research has shown that each of these difficulties is independently associated with an increased risk of adverse health and material hardship. Just being behind on the rent significantly increases the odds of a caregiver being in fair or poor health, having depressive symptoms, and having a child who is hospitalized or in fair or poor health. Instability is also associated with behavioral, emotional, and school problems in children. In teens, it's associated with an increased risk of drug use, depression, and pregnancy.

A systematic review, published in 2015, described the literature around home foreclosure and health. 35 unique studies were identified. More than 90% of them showed that foreclosure was bad for health (including mental health) at the individual and community level. Another systematic review, published in PLOS One that year, found similar results.

On the flip side, there's also evidence that gaining access to stable housing is associated with better health and lower health care costs. A study published in 2016 by the Center for Outcomes Research and Education in Portland, Oregon used Medicaid claims data linked to survey data to explore these links. Researchers studied 145 housing properties, and found that after Medicaid-covered people with unstable housing moved into affordable housing, their total Medicaid expenditures declined by 12%. Their use of primary care went up 20%, and their use of the emergency department declined by 18% Health care expenditures declined by more than $100 per member per month.

A study published in Health Affairs in 2017 found that HUD housing assistance, all types lumped together, was also associated with improved outcomes. Getting assistance was associated with a 5% absolute decrease in the uninsurance rate, as well as reduced rates of unmet needs for health care due to costs. 

The affordability pathway refers to the often skewed balance between housing costs and other necessary expenditures. In 2015, almost 39 million families in the United States had to spend more than 30% of their income on housing. HUD defines such families as "cost-burdened" and acknowledges that such families find it harder to afford food, clothing, transportation, and health care. About 19 million households pay more than 50% of their income in housing, making them severely cost-burdened. And future trend in housing costs are going in the wrong direction.

Parents will often try to live in areas with resources, like good schools or parks, even if they're more expensive than they can really afford. This forces them to skimp on other necessary purchases.

A study published in the American Journal of Public Health in 2011 found that people who fall behind on their mortgage have less access to health-relevant resources, and are more likely to get depressed, have food insecurity, and are less likely to adhere to their medications. Conversely, families with affordable rent payments spend more on insurance, food, and education. They are also more likely to save for buy a future home.

The safety and quality pathway refers to the ways in which low-quality housing affects health. For years, we've known that lead in housing is bad for kids, leading to brain damage and other issues. There are still many areas of the country where lead is in the environment, and in homes, in unsafe levels. Overcrowded housing is associated with lower academic achievement, behavior problems, and poor physical health in children. Homes with water leaks, or with sub-standard ventilation, or with pest infestations can worsen asthma and allergic disease.

And, it's not just kids. A study of hundred of elderly people in 2015 showed that decreasing exposure to high or low temperatures improved blood pressure significantly. Failing to do so leaves many older people at risk. 

We also have evidence that improving the safety and quality of housing makes a difference. The Boston Children's Hospital Community Asthma Initiative focused on removing asthma triggers in housing. It found that there was a 133% return on investment in the first three years after the intervention. If we add in missed school and work days, the ROI is 185%. The intervention not only improved health, it saved money. A similar study in adults showed that reducing asthma triggers improved lung functioning, reduced emergency department visits and hospitalizations, and lowered the need for medications.

Kids who benefited from the Low Income Home Energy Assistance Program saw reductions in the risk of being underweight, with no increase in overweight. They were also less likely to be hospitalized.

A systematic review of efforts to improve the home environments of elderly people led to a 21% reduction on the risk of falls. Among those at high risk for falls, the absolute reduction was 26%, meaning that the number needed to treat is 4! That's huge!

Finally, the neighborhood pathway refers to the ways in which community resources affect health. Access to grocery stores that sell healthy food make it more likely that people will eat better. Improving the safety and cleanliness of a neighborhood can impact both mood and health. Kids who lack safe ways to get to school are more likely to suffer from pedestrian or bike injuries. 

Residential segregation can also be bad for health. Neighborhood with predominantly low-income residents and/or people of color have suffered from historical disinvestment, resulting in more limited access to good schools, employment, and health care and poor health outcomes that accumulate throughout the life course. For example, segregation has been associated with worse outcomes in pregnancy and higher mortality in African Americans.

All of these pathways are important. But, it's important to acknowledge that they don't all have an equal basis in evidence. The research on the affordability pathway, which is perhaps the most obvious (spending more on rent means less than on other things) isn't all that robust, nor do we have a lot of data to show us how to fix it. The evidence base for stability and safety and quality is much more detailed, although we should acknowledge that most of it is from urban areas. The neighborhood pathway has some powerful randomized controlled trials supporting it.

What can we do to fix all this, though? What policies can we consider? Over the next few weeks, we'll be discussing those. Tune in.

[Outro]

Did you like this episode? It's part of a series, and you should watch the whole thing. Click here to see the playlist, and you can do that.

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