Thursday, September 18, 2014

The "Double Jeopardy" Objection to QALYs

I've previously discussed Harris (1987)'s famous objection that the use of Quality-Adjusted Life Years (QALYs) in medical resource allocation is unjustly "discriminatory". Harris' second objection is that the use of QALYs gives rise to an unfair kind of “double jeopardy” (p.190):
QALYs dictate that because an individual is unfortunate, because she has once become a victim of disaster, we are required to visit upon her a second and perhaps graver misfortune. The first disaster leaves her with a poor quality of life and QALYs then require that in virtue of this she be ruled out as a candidate for lifesaving treatment, or at best, that she be given little or no chance of benefiting from what little amelioration her condition admits of. Her first disaster leaves her with a poor quality of life and when she presents herself for help, along come QALYs and finish her off!

Harris makes it sound as though the worse off people are, the less inclined we (QALY advocates) will be to help them. This is of course not true. The QALY approach is an attempt to help people (generally) as much as possible. Whether this is to the advantage or the disadvantage of severely disabled persons (relative to an unadjusted life-years approach) is a contingent matter. To see this, note that if a class of medical treatments tended to yield a fixed prognosis (say of perfect health and capability) regardless of one’s antecedent condition, then severely disabled persons and others with a comparatively low antecedent quality of life would tend to be prioritized over those who are better off to begin with (and so whose prospects in the absence of treatment would be better). For more realistic cases, note that QALYs allow the sensible prioritization of cost-effective “quality-of-life” treatments like cataract surgery over expensive life-extending treatments for the (otherwise able but) terminally ill. So the QALY approach is at least not inherently hostile to the interests of the disabled.

Indeed, on the most straightforward QALY approach, a patient’s antecedent condition is simply irrelevant. All that matters is the forward-looking counterfactual comparison of how many QALYs they stand to gain from treatment versus non-treatment (and how this potential benefit compares to that of other potential beneficiaries of our scarce medical resources, on a ‘per unit’ basis). Prioritarians might modify this approach by giving extra weight to those who are antecedently worse off. On no serious view do the worse off count for less.

The actual phenomenon that Harris struggles to articulate here is rather that the QALY approach is less likely to recommend treatments that offer less benefit to patients. Regardless of one’s antecedent welfare levels, if one’s post-treatment welfare would be very low, then this treatment is not as worthwhile as one that offers greater benefits to its recipients. In practice, this does mean that patients with low quality of life and who would continue to have low quality of life even post-treatment will be less eligible for life-extending treatments than patients who would instead have high post-treatment quality of life. And this could be considered “double jeopardy” in a sense. But it should not be regarded as an objectionable form of double jeopardy. It’s simply to prefer treatments that benefit patients greatly over those that offer less benefit. If one’s condition admits of “little amelioration”, as Harris puts it, then that is certainly a tragedy—but our outrage should be directed at the unfairness of the world, rather than (mis)attributing “unfairness” to the policy of prioritizing treatments that will help their patients more.

Once we appreciate that not all life-extensions are equal, the double jeopardy objection to QALYs thus collapses on similar grounds to the “discrimination” objection. The underlying moral principle is morally innocuous, and the outcomes are good on the whole (if we count all people’s interests equally). What initially sounded so morally repugnant is instead seen to be an artifact of misleading rhetoric and selective attention.


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