The Primary Prevention of Asthma

written by Ted Schettler, MD, MPH
CHE Science Director
Science Director of the Science and Environmental Health Network
Coordinator of CHE’s Science Working Group 

TedSchettlerAsthma is a complex disorder made up of different subtypes with differing causes, underlying pathology, treatment responses, and natural histories. According to the Centers for Disease Control, about 1 in 12 people in the US have asthma, and the numbers are growing every year. The disorder costs over $56 billion in medical costs, lost school and work days, and early deaths annually.

In 2005, CHE’s Asthma and the Environment Working Group convened a series of conversations to explore our interests in this complex disease and to see if we could identify some aspect of asthma around which we could focus our efforts. We began to wonder about the allocation of asthma research dollars. How much is invested in understanding the origins of asthma and opportunities for primary prevention versus how to reduce the frequency and severity of asthmatic episodes in people who already have the disease?

With that question in mind, we reviewed the research portfolio of the National Heart, Lung, and Blood Institute (NHLBI) at the National Institutes of Health and concluded that less than 10 percent of asthma-related research was devoted to understanding the causes and primary prevention of the disease. Even though this was a rough estimate, based on a review of project descriptions in the NIH database, it seemed to indicate that primary prevention of asthma was underfunded.

Following that review, the working group concluded that convening a workshop to address the causes and primary prevention of asthma would be worthwhile. Published proceedings might attract more funding and help to raise awareness of the urgent need. However, we were initially unable to secure support for the proposed undertaking and the idea languished.

In 2009, CHE partner Polly Hoppin, Research Professor and Program Director of the environmental health program at the Lowell Center for Sustainable Production at the University of Massachusetts, Lowell, seized an opportunity to incorporate the primary prevention of asthma into the first Strategic Plan for Asthma in Massachusetts.

Polly worked with partner organizations in the Massachusetts Asthma Advocacy Partnership to draft a goal in the plan to “develop a Roadmap for better understanding the causes of asthma and the role of primary prevention in Massachusetts.” Its objective was to “develop agreement—’a roadmap’—among experts and other groups on the current evidence on primary prevention, research needed to increase our understanding of prevention of asthma, and evidenced-based strategies that can be currently implemented in Massachusetts.” With the goal of primary prevention of asthma clearly spelled out in the state’s strategic plan, Polly and her colleagues successfully undertook new efforts to find resources to convene a meeting addressing the state of the science, research needs, and capacity to reduce new onset asthma over time.

Polly and Molly Jacobs from UMass Lowell organized and led a planning committee that put considerable effort into preparing for the conference, “The Primary Prevention of Asthma: A Symposium on Current Evidence, Research Needs, and Opportunities for Action”, held at the Massachusetts Medical Society in Waltham, Massachusetts, in April, 2013. See http://www.sustainableproduction.org/proj.envh.AsthmaSymp.php for a description, the agenda, and links to presentations. Participants included invited researchers, clinicians, labor and community representatives, public health professionals, and government leaders from a range of sectors, including housing, education, health, transportation and environment. The symposium was co-sponsored by the Massachusetts Department of Public Health, the National Institute for Environmental Health Sciences, the US Department of Health & Human Services, Region I (New England), the Boston Public Health Commission, the American Lung Association of the Northeast, and Neighborhood Health Plan, with in-kind support from a range of collaborating organizations.

Opening presentations helped to frame the multifactorial, multilevel complexity of asthma, its public health impacts, and the structural and cultural underpinnings of asthma disparities. They were followed by experts who had been asked to review the state of the science linking specific risk factors to asthma onset, for example obesity, air pollution (in particular, traffic proximity), indoor allergens (i.e. dust mites and mold), dietary factors, chemicals, and stress, among others. These experts provided a summary of the literature, their analysis, and concluded with a recommended classification of each risk factor under discussion as known, probably, possibly, or known not to be associated with asthma onset. As necessary, risk factors were considered unclassifiable when data were inconsistent or sparse.

Following presentations of the evidence, conference attendees broke out into subgroups to discuss the various risk factors and decide which were “ready for action” based on the state of the science and considering additional factors such as: (a) the magnitude of the potential public health impact given the strength of the association and/or the scale of potential exposure, (b) additional benefits that could be reasonably expected to come with taking action, (c) the likelihood that taking action would result in serious unintended consequences. For those interested in more detail about the risk factors and conclusions reached at the conference see the conference link (above) and a  CHE partner call summarizing the symposium.

At the conclusion of the symposium attendees concurred that the primary prevention of asthma will require multiple, multilevel interventions. Attendees developed a shared understanding of the relevant science and created components of a 10-12 year roadmap as called for in the state’s Strategic Plan for Asthma. Polly is chairing a new primary prevention committee of the Massachusetts Asthma Advocacy Partnership, which is now working with the Department of Public Health to determine which of the symposium recommendations will be included in the next state strategic plan, currently in the planning stages.

Existing evidence supports the importance of avoiding exposure to tobacco smoke and chemicals that are respiratory tract sensitizers or irritants. Living in close proximity to traffic independently increases risk of developing asthma. Chronic stress is also an independent risk factor for asthma and nearly doubles the risk of asthma onset associated with proximity to traffic-related air pollution. Given the state of the evidence, asthma leaders in Massachusetts are committed to ongoing discussion about opportunities for primary prevention, developing policies to reduce exposure to risk factors, and implementing pilot programs with rigorous evaluation to develop effective interventions. Some actions are achievable within the five-year timeframe of the next strategic plan; others will unfold over the longer term as research on effective interventions strengthens. Finding resources to support an implementation research agenda continues to be a pressing need.

Since the Massachusetts symposium, leaders in other states have expressed interest in pursuing a similar strategy to reduce the burden of asthma over time. Our hope is that the primary prevention of asthma will become a more widely shared goal and ultimate reality.