The palliative care community
has been rallying to defend itself this past week in the aftermath of a
scathing attack in the New England Journal of Medicine. A short article written by
Scott Halpern, a specialist in intensive care medicine, asserts that none of
the approaches used by palliative care clinicians, and he singles out advance
care planning tools such as physician orders for life-sustaining treatment (POLST)
and videos depicting CPR, have been proven to work. He implies that the only
way to know whether they are effective is to use the same criteria as those
employed by the FDA in approving a new drug: typically, large, multi-center,
randomized clinical trials. Superficially, this seems advisable—or even, to use
the language that Medicare invokes in determining what it will cover—reasonable
and necessary. It is, after all, a plea for evidence-based medicine, and surely
all right-thinking physicians are in favor of using scientifically supported
treatment. But to propose that we can learn all we need to know about how to
provide excellent palliative care from randomized, double blind,
placebo-controlled trials, studies in which two groups are compared that are
identical in all respects except for the intervention being tested, is sadly
naïve and hopelessly reductionist.
Advance directives are
promoted to enable patients to shape their
own destiny by choosing, with input from their doctors, how they will be
treated when they are seriously ill. Advance care planning seeks to protect
patients by safeguarding their autonomy in the event of incapacity; it also
aspires to help all patients prepare for the future, even those who retain their
cognitive capacity. It’s difficult for anyone to think clearly in the throes of
serious illness; prior consideration of the goals of care can provide a useful
framework for decision-making under stress. But if the point of advance care
planning is to encourage patients to think about their goals and preferences
and to allow them to have a say in their care, then readily
measurable outcomes—things like how much pain patients experience at the end of
life or how many procedures they have or how long they live or what their care costs—are
the wrong endpoints.
A randomized trial doesn’t
make any sense in this setting: we cannot compare patients who participate in advance
care planning (cases) with those who do not (controls) and measure whether the
planners are more likely than the non-planners to get the kinds of treatment
they want. Such a comparison presupposes that everyone actually knows whether
he or she wants attempted CPR or a ventilator or third line chemotherapy in
much the same way that people know whether they prefer vanilla or chocolate ice
cream. But choosing between vanilla and
chocolate requires that people have already tasted both and arrived at a
conclusion about which they like more. With end of life medical treatment,
patients seldom have any prior experience on which to base a decision. They
need help in imagining what they will go through with the various alternatives.
And they can’t sample the different possibilities and then decide (though a limited
trial is sometimes possible): they will only die once. Nor is it accurate to
believe that all patients have well-formed preferences, based on their
religious beliefs or values, and that advance care planning simply informs the
medical profession of those preferences. In many cases, patients don’t have
clear preferences. The
essence of good advance care planning is that it elicits preferences—it helps
patients figure out what makes sense for them, given the realities of their
medical condition.
I’m not suggesting that all formal
study of advance care planning is meaningless. Demonstrating that patients who
go through a planning process are satisfied with their experience is important.
So is comparing different approaches to figure out which one is best received
(or perhaps which patients like which strategy). Assessing whether patients who
engage in advance care planning are more knowledgeable about their options than
those who do not is also useful. So are studies of the implementation of the advance
care planning process: finding out whether advance directives (written
documentation of the planning process) are available to physicians at the time
when decisions need to be made and measuring the concordance between those
requests made in advance and what actually happens. All these sorts of studies
have been done and collectively make the case that advance care planning is
effective.
Although Dr. Halpern longs
for a large, randomized controlled study to definitively determine whether advance
care planning “works,” he seems to be aware of the inaptness of his FDA analogy.
He therefore proposes analyzing electronic medical records using natural
language processing as a way to draw conclusions about the efficacy of various
palliative care interventions, including advance care planning. Nice idea, but
I’m skeptical. It’s not that I’m hostile to natural language processing or
totally ignorant of its power: my son has a doctorate in computer science with
a specialty in natural language processing and does remarkable work studying
how machines can determine the meaning of text. My husband is the co-founder of
a tech start up that makes extensive use of natural language processing. It’s a
promising technique with many as yet undetermined applications. Maybe it will
even prove useful in evaluating advance care planning. But surely we don’t know
that. In fact, there are strong a priori reasons for thinking that mining chart
notes for words that describe a patient’s experience won’t do anything other
than measure how likely a physician is to ask patients about their feelings and
to record their answers.
You might think, reading the New England Journal article, that all of
medicine, apart from palliative care, has been subjected to the standards
demanded by the FDA. You would be mistaken. A great many of the tests and
treatments used regularly by physicians have not been tested with any kind of
rigor. But even more to the point, physicians still use their judgment in
deciding whether to use a given drug in a given patient, even when that drug
has been shown in a carefully conducted randomized clinical trials to be
superior to the alternatives. Randomized clinical trials are typically carried
out in patients who have nothing wrong with them except the condition being
studied. Those patients are rarely over age 65. That vaunted FDA-approved pharmaceutical
is then used in 85-year-old patients with multiple chronic illnesses. Maybe it
will work just as well. But maybe it won’t work at all or will even cause
serious side-effects. It might hasten death. Does Dr. Halpern only use
treatments in his ICU that have been demonstrated in a randomized trial to be
effective—and to be effective in a patient with exactly the combination of
heart failure and diabetes and dementia that the patient before him has?
Of course we need to evaluate the tests
and treatments that we use in patients. But we should use whatever method is most
appropriate for the situation we are studying. Sometimes it will be a randomized
clinical trial. Often it will be a combination of other kinds of studies,
some of which may be qualitative. Whether we conclude that the test or
treatment should be used will depend on the preponderance of the evidence. Only
rarely will we know, beyond a reasonable doubt, that we are doing the right
thing.