Adapting Medical Devices to Society

Knee Replacement X-ray. Photo courtesy of

In 2010, the United States spent $95 billion on medical devices. Although this investment has increased the quality of life for many, the instrument approval process has recently faced scrutiny. A team of Yale researchers led by Lisa Suter, Assistant Professor of Medicine, investigated a method which models the population outcomes and costs of devices used for total knee replacement, a method which could potentially supplement traditional device testing.

Suter and her team used the Osteoarthritis Policy Model, which examines the benefit of treatment received by patients with knee osteoarthritis over time. The health states of patients were defined by their knee symptoms, comorbidity, and quality of life – factors that were assumed to be indicative of future health states and morbidity. By analysing several hypothetical patients, Suter determined the overall efficiency of knee implants for a particular population. The study’s results have profound consequences in that they demonstrate how different groups of people would benefit from such new innovations. For instance, in this model, Suter found that younger, healthier patients experience greater benefit from improved implant durability than older or sicker patients, presumably because younger patients live long enough to recognize small and incremental longterm benefits.

Nevertheless, a degree of controversy surrounds this form of evaluation. “It is definitely not our goal to define who gets which implants, but to raise awareness about these issues,” said Suter, “Patients, physicians, policymakers, device manufacturers and reviewers should be mindful of how novel devices perform in different populations and, where possible, incorporate evidence-based decisionmaking into the process of new device development and approval.”