Monday, November 7, 2011

A Social Experiment


You are where you live. A new study shows that low-income individuals who move to high-income neighborhoods have less obesity and better blood sugar control than individuals who stay in low-income neighborhoods. Past studies have shown that neighborhoods impact their residents’ health, but this is the first to show that changing from one kind of neighborhood to another can positively benefit an individual, even if most other things about that person’s life stay the same.
In the October 20th issue of the New England Journal of Medicine, Dr. Jens Ludwig, et al. published a paper on the health effects observed in the Department of Housing and Urban Development (HUD)’s Moving to Opportunity (MTO) demonstration project. MTO was a case-control study designed to measure the role that neighborhoods play in health. Participants in MTO were randomly selected Section 8 housing recipients in high-poverty neighborhoods in five major US cities. They were divided into three groups. The first group was given vouchers to allow them to move to a new neighborhood with a low level of poverty. The second group was given vouchers to allow them to move to a new neighborhood that was not necessarily different socioeconomically. The third group was not given vouchers. The health of individuals in all three groups was tracked over time.
Those participants who received vouchers to move to higher-income neighborhoods and chose to move were less likely to be obese and less likely to have uncontrolled diabetes than those who did not receive vouchers, even though the two groups were initially very similar. This is an important finding because it highlights the way that where one lives impacts one’s health and that moving can change that impact. Though the reductions in obesity and diabetes were small (around 2-3% overall), they were significant—few other interventions even come close. As Dr. Thomas W. McDade, a coauthor  of the study notes, “The magnitude of the effects of the experiment are striking, and are comparable in size to the effects on diabetes we see from targeted lifestyle interventions or from providing people with medication to prevent the onset of diabetes.”
However, it’s important to keep in mind that the study is, at its most fundamental, a social experiment. HUD does not have the resources or ability to incentivize all Section 8 housing recipients in high-poverty neighborhoods to move to more healthful areas. Even if they did, there are not enough housing options for that to be a feasible option. So, if it cannot be widely implemented, why does this matter, other than to satisfy the curiosity of public health researchers and urban developers? This study opens the door to asking what it is that makes low-poverty neighborhoods that much healthier. Past studies have shown that some features of many low-poverty neighborhoods, like lower crime rates, better access to fresh fruits and vegetables, and parks may have positive effects on wellbeing. MTO is a chance to reexamine these factors and see if there are others, like transportation options and school quality, which might also play a role. Determining which of these are effective can help guide city planners in improving existing high-poverty neighborhoods to make them healthier, even if they do not become wealthier.
This study also makes a case for adding more mixed-income housing in low-poverty neighborhoods. While it is important to not abandon high-poverty neighborhoods (hence the role of city planners and ongoing urban improvement), incorporating more Section 8 housing into low-poverty areas may serve as a stop-gap. Ethically, financially, and logistically, it is not possible to clear out all high-poverty neighborhoods and relocate former residents to low-poverty neighborhoods in the name of public health, but providing individuals with options to live in more mixed-income areas may show a benefit.

Sources:
Anyaso, Hilary Hurd. “From High to Lower Poverty.” Northwestern University News Center. Accessed Nov. 7, 2011 http://www.northwestern.edu/newscenter/stories/2011/10/poverty-study-mcdade.html
Ludwig, Jens, et al. Neighborhoods, Obesity, and Diabetes—A Randomized Social Experiment. New England Journal of Medicine 2011; 365: 1509-1519. October 20, 2011.
Wheeler, Helen Rippier. "Berkeley's Housing Authority Administers Section 8, Public Housing." Accessed Nov. 7, 2011 http://www.berkeleydailyplanet.com/photos/05-14-04/5%253A14%2520rectangle.jpg

Author:
Kira Newman is a second year MD/PhD student beginning the PhD portion of her education in epidemiology.  Her research interests focus on the nexus between environment and health.  Kira brings a broad background to translational research including primary research in historical epidemiology and practical epidemiology experiences at CDC and state levels.  Biking, climbing, and scavenging free food are her passions.

7 comments:

  1. We just discussed this article in Epi journal club this week! The main problems we identified were that health measures were not measured at baseline (i.e., any change in health status could not be determined on an individual level) and of course problems with participation---many of those who got vouchers did not use them. Obviously people cannot be forced to move, so that would be a limitation of any such study. That said, it is a very intriguing study and points to the importance of public health and urban planning to work together more often. One thing the authors did not address---if people move and leave their social network behind, does that temper any health benefit?

    ---Laura Plantinga

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  2. Definitely an interesting question regarding purpose of research -- is it ethical/just/fair to pursue a question that you may ultimately not be able to do something about?

    Also, your post reminded me about this article that I read a few years ago called "Are Your Friends Making You Fat?"

    http://www.nytimes.com/2009/09/13/magazine/13contagion-t.html?pagewanted=all

    Last, this post really calls attention to the interconnectedness of issues impacting health (and hence, the importance of interdisciplinary work to address it!)

    If you have the financial resources to put together your ideal research team to delve deeper into what could explain the findings from this study, what types of people (both content and skill expertise) would you get for your think tank?

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  3. I like your article. As a foreigner who is not good at English reading, I can read your article quickly and understand the main idea easily.

    Lijia Wang

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  4. Kira,

    This indeed sounds like a very interesting social experiment.

    I wonder if the health effects and improved outcomes were similar across racial and ethnic groups?

    I know that the community or social network fostered by some racial and ethnic groups has a protective health effect, even despite socioeconomic factors. I would hypothesize that if individuals move to a community of similar racial or ethnic background, that the improved resources of the community would make a big difference.

    However, I would imagine that moving a family out of a community that they associate with and have strong community ties with and into a community that they do not know or that may be predominately another racial or ethnic group could have a negative impact on their health.

    Were these types of social or network level factors discussed in relationship to health?

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  5. Laura--I think those are valid criticisms. The researchers also mentioned that some of the people in the control group moved even without the support of vouchers. They didn't provide much information on how many of them moved, but it suggests to me that social networks may be more durable than we give them credit for. Also, perhaps those who took advantage of the vouchers may have been particularly self-selecting. One of the things they self-selected for could have been the ability to form new social connections (this is rampant theorizing on my part and not actually in the data). If indeed this flight of speculative epidemiology is true, then forcing individuals to move might, as you say, temper the health benefit, but letting people choose might not.

    Ariela--An interesting ethical question. It's ethics, so feel free to disagree, but I would say that it is still worth researching. Science spends a lot of time studying things that cannot or do not exist beyond the laboratory, and yet we consider this "basic" research to be one of the fundamental necessities for creating new ideas and experiments, even if we cannot execute them now. Similarly, just because we cannot solve a problem in public health with our current tools or social structure does not mean that we should ignore it.
    As for the dream team? For the sake of not writing a comment as long as the blog post, I'm going to leave this open for others to add their thoughts. My short list so far includes anthropologists, biostatisticians, behavioral scientists, dieticians, historians, members of the community, nurses/doctors, urban planners...

    Gillian--According to the article, 90% of the heads of households involved in the study were black or hispanic, but the authors did not break down results by race or ethnicity.
    The measured neighborhood factors that the authors included in the publication were "collective efficacy" (which they define as "the likelihood that adults will take action in response to youth spraying graffiti on local buildings), "respondents reporting feeling safe on the streets near home during the day", "respondents reporting having at least one friend who graduated from college", and "respondents reporting access to local health care services, excluding emergency room".

    --Kira

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  6. Kira, your post is really interesting, and it inspires me to re-evaluate what do scientists pursue for. You're right, although lots of research results cannot be implemented into the reality, it does not stand for it is useless and unimportant. At least, researchers make efforts on presenting these phenomenon to the society, and provide evidence to support it! We may not change the poor to live in a better environment, but we can advocate more attention on helping the poor and narrowing the social-economic gap.

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  7. This is a very interesting post. I was not aware of these sorts of studies. What do you think are the most likely reasons for why low-poverty neighborhoods perform better among the ones you list? Would any simple policies like more and better fruits and vegetables help? What are the best solutions for improving poorer areas for the people who are not able or interested in moving?

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