Patient-centeredness and the Pareto principle: getting at the matter of what matters to our patients

The Pareto principle (also known as the 80/20 rule, the law of the vital few, or the principle of factor sparsity) states that for many events, roughly 80% of the effects comes from 20% of the causes.

                           —Wikipedia

The Standardized Outcomes in Nephrology–Hemodialysis (SONG-HD) initiative is undertaking to provide a guide to the kidney investigative community for outcomes to use in dialysis research studies, particularly randomized trials. Emma O’Lone et al. and the SONG-HD investigators are to be congratulated for their valuable contribution to the growing body of literature that uses innovative and rigorous methods to assess what research questions matter [1]. At the heart of this undertaking is strengthening our understanding of what matters to patients. The goal of clinical research must be to improve outcomes for patients, and the SONG-HD team has wisely incorporated patients in all the steps in their processes.

Patients are, of course, the ‘vital few’, and what patients care about is what we, as healthcare providers and clinical researchers, must care about. Value for the patient is the 20% factor of the Pareto principle. It makes 80% of the difference. Some would say 100%.

In this issue, the SONG-HD investigators report the results from a survey of ~1200 participants, curiously in the Pareto ratio [200 patients (20%) and ~1000 healthcare practitioners (80%)].

The SONG-HD investigators utilize a systematic phased approach with a series of well-defined steps [2, 3]. The first phase is a systematic review of the literature to capture all outcomes used in previous studies; the second phase is a structured group technique with patients and caregivers to identify and rank outcomes; the third phase is a series of interviews with patients, caregivers, researchers and policymakers to elicit values and perspectives and the fourth phase is a Delphi survey of a large group of stakeholders, i.e. patients and healthcare providers. The fourth survey phase incorporates formal ranking procedures [1–3]. A similar approach has been used in ranking outcomes in other conditions.

So what are we learning? One lesson emerging from the SONG-HD studies and other systematic efforts to obtain patient input is that the outcomes that matter most to patients and practitioners are often fully aligned. And, in particular—no surprise—death matters. For physicians, mortality is central to our efforts: we advise dialysis for our patients largely because we expect one or another of the consequences of failing kidneys to be incompatible with life. Avoiding death also matters to our patients. So does avoiding serious adverse clinical events like myocardial infraction and stroke.

There is, however, a critical zone where there are important differences, where doctors and patients do not assign the same priority [1, 4]. The burden of disease and the burden of treatment often weigh more heavily for patients. For example, the SONG-HD team identified fatigue, a factor not regularly captured in most trials, in their initial domain-setting process [2].

We all know that there are many trade-offs in medical care: it is not uncommon for more intensive therapy to offer potential benefits on health measures and even life expectancy, but it may increase the short-term burden of illness. The length of dialysis treatments may be an example of this trade-off, although some recent data suggest that, at least for some subjects, longer, gentler dialysis treatments may improve quality of life [5]. Certainly more conservative options for advanced renal failure care involve trade-offs. For the conversations with patients—the shared decision-making that is critical to patient-centered care—we need to learn more about trade-offs, how to measure them, how to visualize them and how to convert this information into a useful form that can make the sharing of decisions a reality.

The problem of trade-offs was discussed with some wisdom in a recent perspective by a physician living with the choices imposed by breast cancer treatment [6]. She used the analogy of the receiver operating curve, a familiar example that provides a visual illustration for a lab test of the trade-off between sensitivity and specificity. Perhaps we need a similar way to illustrate the trade-offs in the selection of treatment options. Sometimes life prolongation and the direct burdens of treatment are in conflict. We need research data presented in a way that can help individual patients and their care providers find the balance that is right for the individual.

One last worry; it also involves trade-offs, but the trade-offs in clinical research. When designing clinical studies, investigator teams have to make hard decisions about what information to collect and what level of certainty is needed about each and every data point. Certainty—careful adjudication of outcomes—is expensive and slow. So this article and the excellent work of the SONG team—while valuable—does not solve many of the quandaries in trial design about collecting and adjudicating outcomes. I believe it is essential to aim for simplification of data collection in order to moderate the costs of clinical trials. I hope the excellent team of investigators working on SONG will take this challenge on and follow-up their work on outcomes with work on the challenges of definitions and the prioritizing of resources. This would be a valuable complement to the excellent work they have completed so far.

CONFLICT OF INTEREST STATEMENT

None declared. An International Committee of Medical Journal Editors conflict of interest form has been provided with the submission. The views presented in this article are solely the responsibility of the author and do not necessarily represent the views of the Patient-Centered Outcomes Research Institute, its Board of Governors or its Methodology Committee.

(See related article by O’Lone et al. Identifying critically important cardiovascular outcomes for trials in hemodialysis: an international survey with patients, caregivers and health professionals. Nephrol Dial Transplant 2020; 35: 1761--1769)