Is a given health care intervention effective or not? Is it appropriate in a given clinical context or not? Should it be covered by health insurance or not? The search for answers to these questions leads to investment in comparative effectiveness research, the development of guidelines and appropriateness criteria, and payment systems aimed at ensuring delivery of appropriate care and reducing inappropriate care. Although such work is useful, the output has become overwhelming — without resulting in a high-value health care system.
Chandra, Amitabh, Dhruv Khullar, and Thomas Lee. "Addressing the Challenge of Gray-Zone Medicine." New England Journal of Medicine 372.3 (January 2015): 203-205.