Is it time to redefine ‘overdiagnosis’?
As overdiagnosis is increasingly recognized in the realm of cancer care, the term itself might benefit from a simpler, standardized definition, a group of researchers argue in an Annals of Internal Medicine editorial published this June.
“Overdiagnosis represents one harm of ‘too much’ medicine, but the concept can be confusing,” first author Louise Davies, MD, MS, and colleagues wrote in the journal. “It is often conflated with related harms, such as overtreatment, misclassification, false-positive results and overdetection, and is difficult to measure because it cannot be directly observed.”
Davies, an associate professor at the Dartmouth Institute for Health Policy & Clinical Practice and the fellowship director for the Veterans Affairs Outcomes Group, said she and her colleagues wanted to make a distinction between overdiagnosis and several of its related harms or contributors, many of which are inaccurately labeled as overdiagnosis themselves.
“In addition to causing harm through overtreatment, [overdiagnosis] labels a person as having cancer, with all of the psychological, financial, time and opportunity costs that may entail, regardless of whether the cancer is treated or surveilled,” the authors said.
Overdiagnosis differs greatly from its counterparts, like false-positives, incidental findings, misdiagnosis, overdetection of precursor lesions, maldetection, overtreatment and misclassification, Davies et al. said—and to eliminate confusion among the terms, the authors suggested using a uniform, universal definition for the phenomenon: “the detection of a (histologically confirmed) cancer through screening that would not otherwise have been diagnosed in a person’s lifetime had screening not been done.”
The group also provided guidance for talking about and estimating overdiagnosis in a straightforward, accurate way. For example, they wrote, when estimating overdiagnosis in any given case it’s important to be explicit about the definition of “overdiagnosis” that’s being used, specify the time frame over which frequency of overdiagnosis applies and describe the potential harms of overdiagnosis in relation to specific treatments.
When communicating about overdiagnosis, Davies and co-authors said, it’s helpful to avoid graphs and charts, limit numerical information and to keep the message simple. Any language used when defining overdiagnosis should be restricted to an eighth-grade reading level for maximum understanding, and how doctors order and word certain phrases, like potential outcomes, can make a big difference in how someone responds to the information.
“People frequently express preferences inconsistent with their values when the decision is phrased as loss, for example ‘lives or years lost,’” the team said. “Describe outcomes instead.”
Davies et al. wrote they believe accepting a standardized definition and guidance for using “overdiagnosis” correctly can eliminate some of the misunderstanding and negativity associated with the phrase.
“In the future, more public discussions about ethics and values could help communities prioritize which values should be emphasized in cancer screening policymaking,” they said. “Approaching the problem from various angles, including decision aids and shared decision making-strategies at the individual level, media campaigns for clinicians and the public to explain overdiagnosis, and deliberate use of citizen juries to help with recommendations, may facilitate greater understanding.”
After graduating from Indiana University-Bloomington with a bachelor’s in journalism, Anicka joined TriMed’s Chicago team in 2017 covering cardiology. Close to her heart is long-form journalism, Pilot G-2 pens, dark chocolate and her dog Harper Lee.