Patient-centred measurement examines constructs that are not visible outside a patient’s perspective: quality of life, how an illness impacts someone’s work or relationships, or satisfaction with a treatment. Usually assessed via questionnaire instruments, patient-centred measurement is pivotal to ensuring that health care has value.
Leah McClimans’ Patient-Centred Measurement responds to a central puzzle about these kinds of measures. To incorporate patient perspectives into modern medicine, they must be measured and standardised. But these processes are fundamentally at odds with capturing the nuance and variation of patient perspectives.
McClimans analyses, and provides a compelling response to this puzzle. She argues that what is needed to address the puzzle is a procedural theory of patient-centred measurement—a theory of how to best go about it. She then provides such a theory, focused on centering patient voices and taking variation in perspectives seriously.
McClimans’ analysis of the puzzle
McClimans critiques the typical view that the problem underlying this puzzle is a lack of theory: it arises because we don’t know well enough what constructs like ‘quality of life’ mean, or how they will behave.
Drawing on Gadamer, she argues that patient-centred measurement does not need to begin with a theory about what we’re measuring. Instead, it can advance gradually over time, informed by the results of measurement. This implies the need for a procedural theory, a theory of how to best go about patient-centred measurement.
Two criteria for doing patient-centred measurement well
What will this procedural account look like? McClimans draws on scientific and philosophical literature to identify concerns about patient-centred measurement.
One is that measures will tend to capture what the people designing the measures think is important—which might differ from what patients care about. For instance, epilepsy quality-of-life measures designed by clinicians asked about physical functioning, employment, and seizure frequency. But research with people with epilepsy found more concern with stigma and privacy. A measure designed by clinicians might miss this and fail to ask the right questions.
Another concern is that, since patient-centred measurement involves averaging people’s responses to questions, individual variation and minority views are lost. We will fail to meet the aim of capturing patient perspectives if we focus on averages.
This points to two criteria for the best procedure for patient-centred measurement: patients should be involved in developing measures, and interpretations of results should be inclusive of all patient perspectives.
Epistemic dialogue
Developing on the first criterion, McClimans provides a powerful argument for taking patient perspectives seriously.
She examines ways patient experiences are marginalised in favour of standardised or technological measures, such as physical functioning or biomarker levels. Further, stereotypes about illness or disability can encourage us to dismiss what patients say. Patient involvement in designing measures—identifying what constructs are important, and what questions to ask about them—is needed to avoid this.
McClimans acknowledges there can be reasons to query patients’ interpretations. She advocates treating patients’ claims as potentially true, but fallible. Processes of dialogue between patients and experts can subject them to evaluation.
Ongoing coordination
The second criterion concerns how to interpret the results of measures. How can we understand heterogeneous, changing perspectives via measures that standardise them?
McClimans argues we should understand variation—across individuals and over time—as a source of knowledge. A prime example is ‘response shift’. For instance, people with declining mobility sometimes report increasing quality of life. This has puzzled researchers and for some time was dismissed as an error on the part of respondents.
However, it is more useful to take these reports seriously. Declining mobility can be consistent with increased quality of life, as people adjust to declining mobility by altering how they spend their time or what they enjoy. That is, their answers to questions about quality of life change because its meaning, for them, has changed. Dismissing their responses would miss this, reducing how well we understand this construct.
Since interpretations of what patient-centred constructs mean will differ across individuals and over time, there will be a need for ‘ongoing coordination’. That is, patient-centred measures should be continuously assessed and revised.
Responding to issues
The final chapters consider several issues for this approach, and also further clarify connections to some ethical questions.
One issue is whether variation in people’s interpretations of constructs is a hurdle for measuring them. McClimans argues that variation is not at odds with, but enables their measurement. She develops a view that patient-centred constructs are not ‘things in nature’, but artifacts created by our attempts at measurement. This does not mean they are subjective—people’s answers to questions on patient-centred measures do reflect reality, but they are interpretations of reality. Again, this confirms that variation is an important source of knowledge.
A second issue is that patient perspectives could be corrupted, for instance, by industry sponsorship. McClimans argues for including potentially corrupted voices, as exclusion would silence some voices. Instead, we should step up attempts to engage in dialogue and evaluation.
The book is an excellent example of philosophy of medicine done well. It engages in detail with debates in philosophy and science, drawing on philosophical resources to illuminate them theoretically and provide guidance on connected practical and ethical issues. The approach challenges some assumptions about wellbeing and measurement that have rarely been articulated. McClimans’ analyses of a range of measurement-related concepts are important advances in philosophical engagement with patient-centred medicine and measurement science and the epistemological and ethical issues they generate.
Mary Jean Walker, PhD is a senior lecturer in philosophy at La Trobe University, Melbourne, Australia