p>By Caitlin Rothermel, MA, MPHc

Dr Mitchell Katz of the San Francisco Department of Public Health champions the potential role of ‘structural intervention’ as a means to address persistent chronic health problems, in a recent article in the Journal of the American Medical Association.He argues that the efficacy of existing approaches, such as health education, have likely petered out, noting, “It would be difficult to find a sedentary obese smoker who did not know that he should exercise more, eat less, and stop smoking.”

Instead, Katz suggests that efforts be re-focused towards multidisciplinary strategies that endeavour to make targeted changes to the physical, social, or economic environments at the root of selected health problems. Such structural interventions can include adding more walking trails in parks, widening sidewalks and developing more bike paths, which could motivate individuals to exercise more frequently, while added taxes on cars, roads, and/or fuel/petrol might prompt greater use of public transport. Structural interventions can be established via re-thinking institutional design and urban planning systems, through petitions for rezoning, or through the legal system and/or the implementation of new local or national taxes.

But big projects and programmes such as these prompt big questions: What could increase the likelihood that structural interventions are accepted and successful? How do we amass the societal will to proceed? What will the costs of implementation be, and who will pay?

Dr Alexander Tsai of the University of California San Francisco, in a Letter to the Editor regarding Dr Katz’s article, says it is easy to underestimate the hidden, indirect sources of cost in social reform processes, and he cites the work of economist and leading public choice theorist Gordon Tullock. These hidden and often forgotten costs include the costs incurred by lobbies with competing interests and deep pockets, the resource transfers inevitably required for successful program development, and the potential for wasted expenditures when some projects ultimately fail.

In a subsequent interview, Dr Tsai stresses the need to remain humble in the face of limited, robust outcomes data, as well as vigilant to the potential unintended consequences of large-scale transformation. To illustrate, Dr Tsai cites the example of food nutritional labelling, a concept with widespread support, but subject to manipulation. “If food and beverage companies are any good at what they do – which is to encourage more consumption and even over-consumption of their products – then they might attempt to circumvent regulations by engaging in all manner of re-labelling and re-formulating. Governments would then have to respond with further policy tweaks…all of these manoeuvres require a lot of financial resources.”

One can imagine that such indirect costs could quickly become all-encompassing. And as with every good economic analysis, perspective is important. As Dr Katz responds, “the focus of Tullock’s economic theory is the increase of wealth; my focus is the increase in health.”

In conversation, Dr Katz strongly supports a key role for health economists in modelling the potential outcomes of structural intervention initiatives, and suggests that such data could have an impact on bureaucracies and political systems that tend to be resistant to change. He notes that certain EU countries have begun to incorporate structural interventions under the rubric of governmental public health, but that this sort of sea change has not yet happened in the US.

He cites specifically the example of Medicaid, the US health care program for low-income and/or disabled individuals. Medicaid populations tend to have higher rates of obesity and diabetes; however, under existing program rules, Medicaid cannot support structural interventions because funding must be applied directly to Medicaid-eligible individuals.

Dr Katz noted, “We can’t use Medicaid funding to build walking paths near parks in low-income neighbourhoods, although, overall, this might lead to financial savings for Medicaid. Why? The walking path might be used by someone not on Medicaid.” However, Dr Katz also noted that “a health economist could crunch the numbers to show what the overall savings [for each stakeholder] might be.”

Katz is particularly concerned with improving individuals’ physical activity and diet as well as decreasing smoking rates; these are the bad habits known to lead to cancer, cardiovascular disease, diabetes and respiratory disorders, and which are in turn the cause of the majority of deaths in the US and UK.

Because many proposed structural intervention strategies lack robust implementation data, the evidence base is varied. However, according the US Task Force on Community Preventive Services, strong evidence does exist to support the benefits of improved access to space for physical activity, school-based physical education programming, and efforts to reduce tobacco use through excise taxes, public smoking bans, and reimbursement for smoking cessation products. But discussing the role of structural intervention in health management is not purely speculative.

As of this writing, the US continues to debate health care reform, and the bill approved by the US Senate contains a section outlining ‘Community Transformation Grants.’ This legislation pledges to put in place pilot structural intervention programs that address the exact concerns noted by Dr Katz.

In the end, the multidisciplinary nature of structural interventions may sometimes test individual comfort zones in terms of what is considered health provision and what costs are acceptable, but they can also open up new avenues for consideration. In the US, farm subsidies are a political hot potato, but both Drs Katz and Tsai think that agricultural policy adjustments might just be an ideal place to start, if the will could be mustered.

According to Dr Tsai, “If we are truly interested in doing something about obesity, then we should start by taking a hard look at a national agricultural policy that effectively subsidizes the production of high fructose corn syrup and cheapens the cost of unhealthy foods relative to healthy foods.” Adds Dr Katz, “If we are concerned about the cost of social interventions, let’s remove the subsidy for growing corn. That would not cost anything and would save money.” But then the farm lobbyists would begin their fight…

Katz MW. Structural interventions for addressing chronic health problems. JAMA. 2009;302(6):683-685.
Tsai AC. Indirect costs of social interventions. JAMA. 2009;302(24):2661.