Orthotic interventions present special challenges to the clinician trying to build an understanding of the available evidence for decision-making. Depending on the etiology of physical dysfunction, the condition of the orthosis user may change due to myriad factors, many of which are subtle and variable between patients. Function may improve on its own, regardless of intervention, or equally, function may decline. In either of these cases, or even in maintaining the status quo, the orthosis provided to the user may have been helpful—or not. In comparison with prosthetics, where the clinical impacts are more clear-cut, orthotics as a field has to contend with more challenging definitions of success.
For example, the orthotist may have delayed the development of disability considerably, even in the face of inexorable decline of the body. In this case, the best clinical measurements will witness the continued deterioration of the condition of the patient, but orthotically, the treatment may have been very successful. It is extremely difficult to control for this effect in a research study since there are inevitably potent confounding variables related to the specific lifestyles of the research subjects. Were all the subjects at the same point in the evolution of their disabling condition? This is not likely. Do they stretch and maintain strength? Do they wear different shoes? Was the orthosis worn snugly enough, or even worn at all?
This highlights a second important issue to orthotics researchers and to the readers of the JPO. Are we measuring and reporting the best outcome measures to answer the clinical questions at hand? Since not all possible confounding factors are controlled, all research reports will have many inherent assumptions built into the research methods. Read carefully and thoughtfully when deciding what the evidence is really telling you. Highly statistically significant findings of clinically meaningless measures may be less valuable than less significant results of essential outcomes.
David A. Boone, CP, MPH, PhD
Journal of Prosthetics and Orthotics