Map of life expectancy at birth from Global Education Project.

Thursday, August 16, 2007

The Final Enemy

Yes, yes, I know, western civilization is collapsing, but I'll let others worry about that for now and focus on a specific issue.

Americans have a deep need for something to conquer, and so before the Global War on Terror we had the war on cancer and the war on poverty, and the "moral equivalent of war," by which Jimmy Carter meant energy conservation. (The moral equivalent of war? Would that be genocide?) But what you may not have noticed, because nobody labeled it that way, is the war on death. By God, we're going to vanquish it.

In the new BMJ, Dee Manging, Kieran Sweeney and Iona Heath offer a perspective from a slightly less bellicose country when it comes to the sickle-wielding evildoer. (Free full text access! Now how about re-opening the whole journal?) They aren't talking about heroic measures to extend the lives of the desperately ill, but rather mundane preventive interventions such as statins to reduce the risk of heart attacks. It turns out that when people over age 70 take statins, they do indeed have a slightly lower risk of cardiovascular disease morbidity and mortality. On this basis, statins are widely prescribed for elderly people. And why not? When I'm over 70, I'll probably be just as disinclined to have a heart attack as I am now. I don't plan on living forever, but I'm going for 100, because I still have a lot to do.

There's a problem, however -- although the treated group has lower cardiovascular risk, they don't live any longer. They just die of something else. Mangin and colleagues don't see this merely as a pragmatic failure, they see it as morally wrong.

When we vaccinate children in infancy, we are selecting out a cause of death for them, in this case justifiably, because deaths from infectious disease tend to occur prematurely. It is only when we select out causes of death for people who have already exceeded the average lifespan that the endeavour becomes morally questionable. . . . By providing treatments designed to prevent particular diseases, we may be selecting for another cause of death unknowingly, and certainly without the patient's informed consent. This is fundamentally unethical and undermines the principle of respect for autonomy. . . .

Prevention has side effects other than the hazards of the treatment—in particular, the shadow cast over a currently healthy life by the threat of disease, which might be magnified in elderly people for whom mortality looms closer. When we convey risk to any patient we should be cautious—it is like putting a drop of ink into the clear water of the patient's identity, which can never be quite clear again. . . . We should not carry on extrapolating data from younger populations and using linear models that use absolute risks of disease specific mortality and morbidity rather than all cause mortality and morbidity. If we do, the only ones to benefit will be drug companies, with increasing profits from an ageing population consumed by epidemics rather than enjoying their long life.

I am not offering this as a solution to the problem I identify in my previous post. The cost saving from not prescribing statins to people over 70 will be small. Applying this philosophy more broadly and accepting the inevitability of aging as we weigh preventive treatments might make a worthwhile contribution to reducing overall health care costs, but it will hardly solve the problem. (More on that anon.) But it will certainly relieve us of needless preoccupations and allow us to direct our physical, intellectual and spiritual energies in more rewarding directions.

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