UnitedHealthcare is taking some heat for dropping between 10% and 15% of doctors from its Medicare Advantage network nationwide. That means that some enrollees will not be able to continue seeing the physician of their choice. The insurer says the move will save money and improve quality in the long run. Tough sell so far. . . . The publicity surrounding the increase in the number of children being prescribed antidepressants, antipsychotics, and stimulants in the last decade might have paid off, according to a study in the journal Pediatrics. Use soared in the early part of the decade but leveled off between 2006 and 2009. . . . Although the numbers aren’t high, the United States saw a three-fold increase in measles last year — only 175 cases, but the disease is considered officially eliminated from the Western Hemisphere. That means it does not circulate within the general population but rather is entering the country with travelers, according to the Centers for Disease Control and Prevention.... Exercise reduces the risk of breast cancer and a study in the journal PLoS One says that it even helps once breast cancer is diagnosed. Women who exercise are 40% less likely to die from the disease than those who do not meet exercise guidelines. Those guidelines are not especially strenuous: seven miles of brisk walking or five miles of running a week.... The U.S. Preventive Services Task Force (USPSTF) is at it again. The task force often gets headlines when it rules that some test (such as mammography) might be overutilized. Now the USPSTF says that screening to identify early-stage dementia might not be worth it. The findings are in a study in the Annals of Internal Medicine (http://tinyurl.com/task-ruling) that the task force sponsored.