In Pursuit of the Ever-Expanding Shoreline

Professor Michael Smithson,¹ who has written on the topic of ignorance, uses the very helpful metaphor of a “knowledge island,” which was introduced to me by Dr. Sandro Galea, Dean of the Boston University School of Public Health.² The more we know, the bigger the knowledge island becomes. We are most comfortable at the center of the island, where we know what we know; however, the bigger the island, the longer the island's shoreline, where the limits of our knowledge lie. As researchers and clinicians, we grapple with the fact that we spend much of our time on that shoreline, at the intersection of knowledge and ignorance.

In an opinion piece in The New York Times, Jamie Holmes noted that the study of ignorance—agnotology—is growing.³ We could extrapolate from his essay that physical therapist education programs should emphasize the teaching of ignorance, not evidence-based practice. As Holmes argued, the study of ignorance rests at the ever-expanding shoreline of knowledge.

I find the Times opinion piece fascinating as I consider how clinicians and scientists go about their work and as I contemplate the rightful role of a professional journal such as PTJ.

As rehabilitation professionals, we aspire to improve our patients' health and to produce scholarship that helps us understand how to do that ever more effectively. Success rests on the production of new knowledge—on getting ourselves to the center of the knowledge island so that we can then design new clinical treatments. For instance, a growing body of scholarship suggests that physical therapist intervention in the intensive care unit (ICU) improves functional mobility, promotes weaning from mechanical ventilation, and reduces hospital readmissions,^4,5 and the physical therapy profession has been advocating strongly for the introduction of physical therapists in the ICU to improve patients' health.⁶ Similarly, there is evidence that falls in the elderly can be prevented by screening to detect risk factors and by the implementation of tailored interventions by the physical therapist or other health care professionals.⁷

But what about when the evidence is ambiguous—when we are walking on the shores of the island? What do we do when we do not know what the right intervention is? This state is far from uncommon, and, in fact, is probably much more the norm in physical therapy and rehabilitation than we would like to admit. Take low back pain, the world's major cause of disability. Most systematic reviews on treatment have recommended various physical therapist interventions, such as strengthening, endurance, directional preference exercise, manual therapy, and trunk coordination.⁸ However, as Azevedo and colleagues recently noted,⁹ some studies comparing the relative effectiveness of these interventions have shown small-to-moderate clinical effects, with no treatment strategies that are clearly superior. What are we to do with such clinical uncertainty and ambiguity?

“Our students need to become comfortable in the grays of the shoreline, and to understand that physical therapy remains a pragmatic discipline even when there is uncertainty.”

As clinicians, we need to recognize that ignorance is an inevitable part of what we do. Interventions might not be necessarily based on published evidence, and we can—and frequently should—act even when we do not know all the answers. Action can be predicated on theory, on past clinical experience, on the likely prognosis in our patients, or on scientific evidence. But when we act in the absence of scientific evidence, we should not do so on false pretexts, invoking knowledge and clarity when in fact ignorance of causal effect and ambiguity are the order of the day.

It is okay to admit that we currently lack evidence of the comparative effectiveness of different physical therapist interventions for the treatment of chronic low back pain; it is okay to admit that the evidence is not entirely clear regarding exactly what interventions should be provided after screening to prevent falls in the elderly. Ignorance is a great motivator. It drives us to find the evidence about when, why, and how we should intervene. It also motivates us to intervene with honesty about the uncertainties, allowing us the option of changing course when some of our ignorance falls away in favor of new evidence.

As scientists and researchers, we have the extraordinary privilege of focusing on the expansion of the knowledge island. Although ambiguity about the effectiveness of a physical therapist intervention is never a cause for celebration, it does give occasion for important questions to be asked, interesting studies to be conducted, and vital answers to be discovered. What could be more engaging for those of us charged with generating knowledge as our core mission? Our patients compel us to engage big clinical questions. We want to understand the causes of movement impairments, activity limitations, and participation restrictions—to generate new evidence so that new knowledge can be disseminated to those who are in a position to improve patients' health.

As teachers, we know that ignorance and ambiguity based on tradition and experience are far less useful to transmit to our students than scientific evidence. However, false certitude is a temptation and not without consequence. The obvious unintended outcome is the taking of action that turns out to be inadvertently harmful. Physical and neurocognitive impairments secondary to critical illness in patients in the ICU are pervasive,⁸ and patients and families cry for rapid answers; there is pressure to take clinical action. Surely we need to know which interventions will be most efficacious so that we can act quickly to reduce the barriers preventing us from helping these patients! Embracing our ignorance frees us to be clear about when we do not know what to do and to articulate more definitively when and how to act. It also suggests that we should prepare our students to deal with the ambiguity of “inadequate evidence for practice,” similar to Craik's 2001 call for “a tolerance for ambiguity.”¹⁰ Our students need to be comfortable in the grays of the shoreline, and to understand that physical therapy remains a pragmatic discipline even when there is uncertainty. In my view, the embrace of ignorance is just as important as the adoption of evidence-based practice.

What is the role of PTJ with respect to the ever-expanding shoreline of the knowledge island? First, PTJ serves as an important vehicle for disseminating new knowledge and moving more physical therapists to the center of the island so that they may then design new clinical interventions to promote the health of our patients. Second, PTJ has the obligation to assist our profession in identifying where clinical ambiguity exists, providing a forum for important questions to be raised, and formulating interesting studies to be conducted.

Finally, PTJ will support the training of our emerging clinicians and scholars by providing content that helps them to be more at ease with the partnership between knowledge and ignorance—and to accept that much of their careers will happen on the ambiguous shoreline.

• © 2016 American Physical Therapy Association