How big is the problem of low-value care? It’s hard to know, because it depends on how you measure it. In a recent BMJ Quality & Safety article, health care researchers Kelsey Chalmers, PhD, Sallie-Anne Pearson, BSc, PhD, and Lown Institute Senior Fellow Adam Elshaug, PhD identify a pressing problem in overuse research—too few studies directly quantify how much low-value care exists, and those that do quantify low-value care measure it in different ways.
The ways we measure low-value care can “greatly impact the reporting and interpretation” of overuse research, the authors write. For example, when a study finds that 0.2% of Medicare beneficiaries received unnecessary knee arthroscopies, that doesn’t sound like such a big problem. However, when another study shows that 57.2% of knee arthroscopies are unnecessary, a reader might sit up and pay attention. This discrepancy occurs because the vast majority of knee arthroscopies are unnecessary, but they are also not performed very often.
On the other hand, there are procedures that are used unnecessarily on patients with certain indications, but are used appropriately most of the time overall. For example, carotid ultrasounds (high-frequency imaging of a patient’s carotid arteries) are performed unnecessarily just 6.5% of the time. But for patients admitted for fainting with no other symptoms, 16.2% of will receive an unnecessary carotid ultrasound. Reporting on just one of these results gives us only one side of the story of how that service is overused.
Unfortunately, most studies do not include measurements of low-value care from different perspectives. In a review of 40 published papers that directly measured low-value care services, the authors found only four studies that reported the proportion of patients receiving low-value care AND the proportion of services performed that were low-value.
Research on low-value care has advanced significantly in the past decade, but we still have a long way to go before we truly understand the crisis of overuse. Quantifying low-value care from different perspectives is a good place to start.