K M Venkat Narayan: A case of well-intentioned public health reductionism?

venkat narayanThe Institute of Medicine (IOM) recently released its elegantly titled report, “A Population-Based Policy and Systems Change Approach to Prevent and Control Hypertension” (Washington, DC. National Academies Press, 2010).
The words, “population-based,” “policy,” and “systems change” all eloquently and appropriately emphasize the role of public health; the IOM study was, indeed, sponsored by the US Centers for Disease Control and Prevention (CDC), the nation’s lead public health agency.

There are several good things about the IOM report. By calling hypertension a “neglected disease,” the report draws attention to the fact that despite high blood pressure being the cause of death in one in six American adults, millions are developing it, a high proportion of those with it remain undetected, a high proportion of those detected remain inadequately treated, and a large number continue to unnecessarily die from hypertension. The United States has witnessed a 25% increase in the death rate from high blood pressure during the decade from 1995 to 2005.

The report also correctly highlights the failure of translation of available scientific knowledge into effective prevention, treatment, and control programs for hypertension. The recommendations of the IOM report are: to strengthen collaboration between the CDC and related agencies to tackle hypertension prevention efforts; to monitor sodium intake; to work with industry to promote actions to reduce salt intake at the population level; to improve the reporting of hypertension; and to improve the quality of care and to remove economic barriers to effective anti-hypertension treatments.
On the face of it, these recommendations appear wholesome and comprehensive. On a deeper examination, however, one wonders whether there is tendency toward over-simplifying a complex problem by resorting to single-agenda approaches – almost an eerily infectious diseases’ approach to complex chronic diseases?
Unlike infectious diseases, the causes of chronic conditions, such as vascular diseases, are multi-factorial and complex. For example, hypertension is one of several inter-related risk factors for vascular disease, and a high proportion of those with high blood pressure may also have poor lipid profiles, high glucose levels, obesity, etc.

Instead of drawing singular attention to hypertension and risking the creation of a single risk factor “silo,” wouldn’t it be more efficient and more effective to promote multiple risk factor control (i.e., high blood pressure, abnormal lipids, high glucose, and overweight)? In fact, strong evidence exists from several diabetes prevention trials, among those at high risk, that aggressive lifestyle interventions delivered to individuals – by creatively connecting the clinic and the community – can reduce progression to diabetes substantially, and can also improve cardiovascular risk factors; improving delivery of multiple risk factor control (e.g., innovative combination pharmacotherapy of low-cost generic drugs; non-physician care coordinators; record and decision support systems for identification, triage, reminders, follow-up, referrals) is feasible.

Improving diet and physical activity in the population is, without doubt, important to preventing vascular risk factors and disease. The IOM report, however, by overly emphasizing salt reduction may have inadvertently fallen yet again into a reductionism trap – that of getting the public and the policy makers to focus on a single villain, namely, salt. In fact, healthy nutrition is far more complex, and should be comprehensively addressed through policy measures aimed at the underlying practices of modern day food production, processing and distribution and also through holistic health education. (Read Michael Pollen’s books “The Omnivore’s Dilemma” and “In Defense of Food.”) One fears that the “salt reduction” policy mantra could be a distraction – of hitherto empirically untested public health impact – and may bail policy makers out of the more challenging and inconvenient actions needed to reform population nutrition to prevent chronic diseases and to promote health.

The IOM committee is on the mark for calling a “systems change”. A “system” is “a group of interacting, interrelated, or interdependent elements forming a complex whole” (www.thefreedictionary.com). By singularly highlighting hypertension, without placing it within the overall context of the plurality of risk factors for vascular diseases, and by overly emphasizing the single-agenda of salt reduction – instead of seeking comprehensive improvements in population nutrition – the IOM report may have accidentally missed the point of a systems approach. Instead, it has tried to simplify the challenges of chronic disease prevention and control to akin with controlling a single-agent, single-cause infectious disease.

The American journalist H.L. Mencken, lovingly remembered as the “Sage of Baltimore.” once remarked that “For every complex problem, there is a solution that is single, neat, and wrong.” Yet, humans find it is easier to try and over-simplify complexity and to want to focus on single agendas and single solutions – e.g., raise the profile of hypertension, reduce salt intake through policy to prevent and control hypertension. This approach may help generate greater resources for hypertension control and promote over-zealous and untested policy actions against salt intake. Do we, however, run the risk of missing the “big picture” – that of comprehensive lifestyle and pharmacological approaches for multiple risk factor control for prevention of vascular diseases – heart attacks, strokes, chronic kidney disease?

K.M. Venkat Narayan is Ruth and O.C. Hubert Professor of Global Health and Professor of Epidemiology and Medicine at Emory University Atlanta. He is a product of three continents, having lived and worked in India, United Arab Emirates, United Kingdom, and United States of America.