Monday, December 30, 2013
Public Health, Personal Choice
by Ryan Seals
We are in the position, unique in human history, of possessing the knowledge of how to alleviate much of the unnecessary suffering in the world. What we lack is the knowledge of how to deliver and disseminate that knowledge, and of how to encourage its uptake. In an eerily prescient article of the sort at which he excelled, John Maynard Keynes wrote in The New Republic in 1932:
At present the world is being held back by something which would have surprised our fathers—by a failure of economic technique to exploit the possibilities of engineering and distributive technique; or, rather, engineering technique has reached a degree of perfection which is making obvious defects in economic technique which have always existed, though unnoticed, and have doubtless impoverished mankind since the days of Abraham.
Replace engineering technique with scientific understanding and economic technique with, well, some broadly defined sociopolitical will to implement our understanding, and Keynes's point is precisely applicable to the current state of health and longevity around the world.
Whether you read into modern medicine an amazing ability to deflect and defer nature's slings and arrows, or you bemoan the failed ‘War on Cancer' and the much-delayed genomic revolution, the fact remains that we now know the major ways for the majority of people to lead long, healthy, lives. It isn't medical technology that allows people to live into old age; with the exception of vaccines, the causes of good health aren't to be found in hospitals and medical clinics. Nutrition, sanitation, and hygiene are the keys to population health, and it isn't too great an exaggeration to say that health depends, above all else, on where you live, eat and excrete. The solutions are, for the most part and in a strictly technical sense, rather simple and well understood.
Keynes wrote that statement in 1932, before modern vaccines and antibiotics, without much (successful) interventional surgery, and with scant knowledge of the mechanisms of disease. The 80 years before he wrote had seen a revolution in human health – maximum life expectancy had long been on its steep upward trajectory, and infant mortality in the Western world was fast becoming a rarity.
Overall progress in human health and longevity has been more or less constant for the past century and a half, an observation too often overlooked. If I were to nominate the single most important graph, I would point you to one produced by Jim Oeppen and James Vaupel for a 2002 article [pdf] in Science, shown below. It plots, since 1840, female record life expectancy (in other words, the best life expectancy on earth at any given time). What strikes one first is the linearity; the increase in best-performance life expectancy, while admittedly moving about the globe, has been quite constant. The slope, however, is the truly startling feature of the graph. Record life expectancy for women has increased at a slope of 0.24, meaning that two children born four years apart have been expected, on average and over the past century and half, to have an entire year difference in their life expectancy. If you are 40 years old, a child born today would be expected to live a full decade longer than you. (The horizontal lines denote various – erroneous – predictions of where life expectancy would peak. While the point here is a different one, such plots are a good antidote to overconfidence!)
That having been said, it's no secret that inequalities in health and longevity exist today, at greater levels than perhaps ever before. The Robert Wood Johnson Foundation has created a startling series of maps as depressing as the above is heartening, showing inequalities in life expectancy that exist within cities. These are individuals living just down the highway from one another. Within greater New Orleans, for example, there is a spread of 25 years between the highest and lowest life expectancies. While not as extreme, the pattern repeats in DC, Kansas City, Minneapolis, and the San Joaquin Valley.
The causes of such inequalities are many, and often complicated. Smoking, diet, environment, unemployment, crime, access to healthcare… a list to which much more could be added. But the fact that we can even make such a list, and with some degree of confidence explain the causes is something new in human history. We may have partly bumbled our way into our current state, but once here have come to understand it.
It's often said that public health deals with irreducibly ‘social' goods. Like neurons giving rise to the emergent property of consciousness, there are public health values – equality and access to name but two – that cannot be defined in any meaningful way at the individual level, and this justifies approaches that value the population over the individual. But the analogy fails in that consciousness, the emergent property of neurons in cooperation, is the ultimate valuable property; neurons are interesting only insofar as they support consciousness. The opposite is true in public health. All of the supposedly social goods are made meaningful by their effect on individuals. Inequality matters only when it is embodied in individuals, and affects their individual lives. In this it is important to remember that, while Maggie was wrong to argue "there is no such thing as society," she was right in her next line: "There are individual men and women, and there are families." The latter live in the former; but the former is real, and certainly affects the latter.
Now that we understand the causes and consequences of health inequalities, it has become incumbent on society to alleviate these inequalities. The rapid rise in the number and prominence of global health goals in the past half-century attests to this. We look to science to implement these changes in a more effective way than might otherwise be achieved; "otherwise" referring to blindly hoping for economic growth and a recurrence of the blind process by which much of the Western world has achieved long, healthy lives.
Fallibility is built into the process by which scientific evidence is accrued, and it might be left at that; so long as one remains open to new evidence, blind allegiance is effectively precluded. But of course there is, at the individual level, another equally important kind of fallibility, and it deserves a word of mention. Individuals are often at odds with the prevailing wisdom of the day. In some arenas we might write such persons off as charmingly idiosyncratic, but more and more we tend to criticize individuals for not following "best practices."
Once a fact or theory becomes well established, particularly in an arena related to personal health or safety (smoking, seatbelts, weight control) we tend to moralize, and judge negatively those who, for whatever reason, extend their eccentricity to false beliefs in such areas. When individuals, by choice or circumstance, seem to be at odds with the accepted knowledge of how to improve their health, we naturally look to encourage them to adopt better behaviors. This sums up, quite baldly, a great deal of public health research today.
The operative word in that last paragraph though, was ‘encourage'. On the boundary between encouragement and compulsion, a little Locke is in order:
Every man has commission to admonish, exhort, convince another of error, and, by reasoning, to draw him into truth; but to give laws, receive obedience, and compel with the sword, belongs to none but the magistrate.
The more difficult type of fallibility, incumbent on those of us who engage with false belief, is to remember that we compel as man, not magistrate. This fallibility doesn't necessarily imply a rejection of legal means, or even certain types of compulsion, only a considered reluctance to impose our beliefs on others – one of the pillars, after all, of liberal democracy. If chiropractic and herbal supplements are being sold as medical interventions, they should be regulated as such. But outright prohibition, misguided as these techniques may be, is an illiberal overreach. Whether you hold individual liberties as the foundation of morality, or you believe that respecting individual liberties is the surest way to encourage human wellbeing, modern progress has been founded on a respect for individual rights, wrong as individuals so often are.
And thus we return to the modern technocratic idea of the "nudge". Can we, without significantly curbing individual's choices, encourage behaviors that lead to demonstrably better social indicators of health and longevity? There is, of course, a wealth of work to be done at the purely societal level: environmental improvements, economic growth, healthcare access. But even these involve impacts on individuals, if only in the decision of how to allocate limited resources. The two approaches converge on the question of what a significant constraint on individual choice means.
My goal over the next few months will be to explore the gap between, in Keynes's words, "engineering technique" and "economic technique", particularly in the realm of health and longevity. How does evidence become translated into health policy? What do we know about long, healthy lives, and why don't more people live them? How do we, how should we, value health and longevity? Is the push towards a technocratic approach the right one, or are there intractably moral and political questions to be answered, touching on deep values about what constitutes the best way to live? (hint: I think the answers are yes and yes). I encourage comments and suggestions about avenues to explore.
In that same article Keynes displayed an admirable sense of perspective. "My goal is the ideal; my object is to put economic considerations into a back seat." Always one to recognize that economics serves in the interest of human flourishing, Keynes looked forward a time when mankind could afford to do what was right, rather than only that which was "economically sound". Our ideals change with progress, but we always have them. The gap between reality and the ideal is real and, by some accounts, growing. Understanding the gap, when we can explain it so well, if only at one level, is the challenge of the 21st century.
Posted by Ryan Seals at 12:40 AM | Permalink