TUESDAY, July 21, 2026 (HealthDay News) -- Better physician knowledge is associated with lower use of low-value services (LVS), according to a study published online July 13 in JAMA Internal Medicine.Jonathan L. Vandergrift, from the American Board of Internal Medicine (ABIM) in Philadelphia, and colleagues assessed whether use of 25 LVS is associated with physicians' general clinical knowledge as measured by the ABIM's longitudinal knowledge assessment (LKA). The analysis included 7,089 general internists enrolled in the LKA in 2022 or 2023 caring for 898,365 Medicare fee-for-service beneficiaries aged 67 years or older.The researchers found that having a physician with a top quartile LKA score was associated with a significantly lower chance of receiving any LVS during the year (31.0 percent in the bottom quartile versus 28.6 percent in the top quartile). There were also significant differences by LVS subtype including diagnostic or preventive testing (10.4 percent versus 8.7 percent in the bottom versus top quartile), cancer screening (13.8 percent versus 12.3 percent), and imaging (13.8 percent versus 13.2 percent). For individual LVS, differences by LKA score quartile were most prominent for total and free triiodothyronine testing in patients with hypothyroidism and prostate-specific antigen testing in males aged 75 years and older."Though health systems, policymakers, insurers and individual physicians all play a role in trimming costs of care, we are encouraged to see that physician expertise may be a powerful lever in helping reduce the use of unnecessary and often costly tests and treatments," senior author Bradley M. Gray, Ph.D., also from the ABIM, said in a statement.Abstract/Full Text (subscription or payment may be required).Sign up for our weekly HealthDay newsletter