The use of medications such as antihistamines and NSAIDs, which are taken intermittently to treat symptoms, was sensitive to co-payment changes. Other medications—antihypertensive, antiasthmatic, antidepressant, antihyperlipidemic, antiulcerant, and antidiabetic agents—also demonstrated significant price responsiveness. The reduction in use of medications for individuals in ongoing care was more modest. Still, significant increases in co-payments raise concern about adverse health consequences because of the large price effects, especially among diabetic patients.
In recent years, many health plans have implemented policies to contain drugs costs, including raising beneficiary co-payments, mandating use of generics, requiring mail-order services, and expanding use of formularies, all of which have large effects on total drug spending. For example, doubling co-payments reduced total drug spending by 19% to 33% in one multiyear study of 25 companies. Such large responses often raise concerns about adverse health consequences, particularly for chronically ill individuals. Indeed, large changes in drug benefits are sometimes associated with substantial morbidity and mortality in certain high-risk populations.JAMA Network