What the POLST research base should be able to show

The moral justification for using the POLST is based upon the form being an exercise of an individual’s autonomy in controlling his or her end-of- life care so research showing that the form is a bona fide exercise of such autonomy is crucial. Studies should show us that when the POLST is completed in the way intended by its designers, the treatment selections written on the form accurately reflect the authentic preferences of a large majority of patients using the form across of a variety of probable end-of-life scenarios.

Research should also establish that doctors and nurses follow what is written on the POLST form. We also want to be confident that it is the POLST form, rather than some other intervention or factor, that is causing the compliance.

Since the POLST is intended to address shortcomings in living wills, and use of the form requires institutional changes in process and procedure that are not costless, we should want to see some studies showing that the POLST is more effective than living wills in translating written end-of-life treatment preferences into care at the bedside. Ideally, we would like to see a study that looks at whether compliance with written treatment instructions is significantly better with the POLST than with living wills.

We should want to see studies that show that the POLST works across treatment settings and among diverse populations. If the POLST is only effective in hospitals or nursing homes, or if its effectiveness is limited to certain racial, ethnic, or cultural groups, then its utility is limited.

Finally,research should also demonstrate that the POLST is being used by providers in the way intended by its designers. We need to have some assurance that when use of the

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POLST is translated from theory into practice it does not become an instrument for implementing provider treatment preferences, rather than those of the patient. Even POLST advocates acknowledge that “with poor training, inadequate resources, and insufficient evaluation, the process can regrettably morph into another trampling of patient autonomy” (Bomba & Sabatino, 2009).

Research that is used to make public policy and serve as the basis of institutional change should not only address the above hypotheses, but should also be scientifically useful. This often means quantitative research that is carefully designed and implemented to have both internal and external validity. A study is internally valid if it is designed in such a way that one can be confident that the observed effects are due to the intervention being examined, rather than resulting from something else (Shortell & Richardson, 1978, p. 38). A study has good external validity if its results can be generalized to other situations. Hypothesis testing is commonly used in quantitative research as the basis of study design. Greenhalgh (2001) suggests that the hypothesis being tested should be clear in any quantitative research paper.

Here, I propose six hypotheses that should have ample evidentiary support before the POLST is adopted by medical institutions and policymakers. Of course, how much proof constitutes “ample evidentiary support” for the listed hypotheses is a value judgment. The important thing is to get data upon which such judgments can be made. The hypotheses - and some suggested ways of testing them or otherwise developing good supporting evidence - are as follows:

H1: The POLST accurately captures authentic patient treatment preferences when completed in the way intended by its designers. This hypothesis might be

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tested by comparing the treatment preferences indicated on a sample of POLST forms with the preferences elicited shortly after POLST completion through use of a validated preference measuring instrument that includes multiple scenarios. An example of such an instrument is the Life Support Preferences Questionnaire or LSPQ (Beland & Froman, 1995). Kappa statistics showing a high degree of agreement between the POLST and the validating instruments might be used to provide evidentiary support for this hypothesis.

H2: The POLST form causes doctors and nurses to follow the written patient treatment instructions expressed on the form. This hypothesis might be tested by comparing the instructions on a sample of POLST forms with the actual end-of-life treatment received by individuals subsequent to the POLST being signed, and also by comparing the treatments received by individuals with a POLST with care received by individuals without a POLST. With respect to the latter inquiry, the null hypothesis should be that the POLST makes no difference in care. H2 might be adequately demonstrated by results showing a high degree of consistency between orders on the POLST and the care received, and also by results showing that completion of a POLST makes a statistically significant difference in the kind of care received by individuals when compared to situations when no POLST was completed.

H3: The POLST is effective in all treatment settings where it is recommended for use and across diverse populations. This hypothesis might be tested by conducting the studies recommended for H2 in a variety of treatment settings such as nursing homes, hospitals, hospice, and in the community.

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H4: The POLST is more effective than a living will in securing end-of-life treatment consistent with a patient’s written instructions. This hypothesis might be tested by comparing the consistency of care received with written treatment instructions for individuals who had a POLST versus those who had a living will. The null hypothesis would be that a POLST is no better than a living will in directing end-of-life medical treatment. H4 would be demonstrated by studies showing that a POLST makes a statistically significant difference in whether care conforms to treatment instructions when compared to a living will.

H5: The POLST does not harm patients by causing the withholding of treatment that is desired and should be provided. This hypothesis might be demonstrated by examining the end-of-life treatment received by individuals who had a POLST and looking at whether any medically appropriate life-sustaining treatments were withheld or withdrawn without specific authorization on the POLST form, or from the patient or a surrogate.

H6: The POLST is implemented in medical institutions in the way intended by its designers. Researchers might borrow the tools of evaluation and use a process evaluation to examine whether the POLST is actually be implemented in the field in the way intended by its designers. A process evaluation might include surveys of medical personnel who help individuals make selections on the POLST, and also involve the actual observation of POLST form completion.

In the next section, I review the POLST studies published prior to finalization of this dissertation in October 2012. I show that the existing research base is deficient in addressing

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the six hypotheses identified above, and that most of the studies have significant methodological deficiencies that limit the ability to generalize from the results.