Today's open access review paper summarizes the results and methodologies of a number of epidemiological studies in which the authors found there to be surprisingly little variation in mortality resulting from unequal access to healthcare. The analysis of data attributes something like 5% to 15% of overall variation in mortality to differences in healthcare access. Lifestyle choices such as smoking, diet, exercise, and obesity are the largest contribution, accounting for perhaps as much as half or more of the total variation in mortality across populations.
What might we conclude from this sort of analysis? One possibility is that access to healthcare is in fact not all that unequal where it really matters, such as treatment of dangerous infectious disease. The truly vital services, those that are proven, low cost thanks to expiration of patents and economies of scale in production, and that have the most significant effects on mortality in specific cases, are available to near everyone in the study populations. That also implies that those paying for more expensive healthcare services are, on average, obtaining little benefit for the added expense, beyond the signaling effects that attend any conspicuous form of high end consumption.
Another possibility, quite familiar to this audience, is that when it comes to age-related diseases, the medical technologies of the past few decades are just not all that good. Treatments have failed to address the causes of aging, and instead took on the impossible task of trying patch over the consequences in a failing system. The result, with very few exceptions, such as treatments to control blood pressure and blood cholesterol, is therapies offering only marginal, unreliable benefits and little impact to mortality. It remains the case that in the matter of aging, maintaining fitness and slimness is more reliable or even more effective than most of what has been offered by medical science over recent decades. Only with the advent of true rejuvenation therapies, those targeting important mechanisms of aging, such as senolytic treatments that selectively clear senescent cells, will this state of affairs begin to change.
It is often argued that improvements in population health, and life expectancy in particular, are best pursued via investments in medical services. Over the last few decades evidence has accumulated, showing that more powerful determinants of health and life expectancy lie elsewhere. Making high-yield investments to extend life expectancy requires an understanding of the relative contributions of health care and other determinants of health to health outcomes. It is estimated that a lack of access to medical care accounts for only about 10% of premature deaths. The methodology underlying these estimates, however, remains obscure. In this article we review four different estimates of the contributions of health care to premature mortality and other health outcomes.
The estimates converge around Schroeder's conclusion that health care accounts for between 5% and 15% of the variation in premature death. The various methods were consistent in showing that social and behavioral factors account for a much higher percentage of the variation in premature mortality than health care does. For example, the McGinnis/Schroeder method estimates that social circumstances account for about 15% of the variance in early mortality. The Wennberg method estimates that social circumstances account for 29% of variability, and the Park model estimates that social effects account for 46%. Similarly, the McGinnis/Schroeder method estimates that behavior patterns account for 40% of the variability in early mortality, the Wennberg method estimates 65%, and the Park method estimates 29%. In sum, these methods indicate that social and behavioral factors account for substantially more of the variability in premature mortality than health care does.
The suggestion that health care services account for only a small percentage of the variation in national life expectancy has important implications. Both personal and institutional health care expenditures are justified by confidence that health care spending enhances longevity and other indices of population health. Efforts to model the value of health care spending often assume that 100% of the variation in health outcomes is attributable to health care services. Even the most sophisticated models assume that 50% of the variation in population health is attributable to health care. Our analyses reaffirm the belief that health care is one component of a larger set of influences on health outcomes.