1. Short title This Act may be cited as the Combating Opioid Misuse By Advancing Treatment Act of 2018 or the COMBAT Act of 2018 . 2. Study on best practices in use by Federal Government to reduce opioid usage following medical procedures (a) Study The Comptroller General of the United States, in consultation with the Secretary of Health and Human Services, the Secretary of Defense, the Administrator of the Centers for Medicare & Medicaid Services, the Director of the National Institutes of Health, and the Commissioner of Food and Drugs, shall conduct a study on best practices in use by Federal departments and agencies to reduce opioid usage following a medical procedure that is conducted, funded, or otherwise supported by such departments and agencies. (b) Topics The study required by subsection (a)— (1) shall— (A) include analysis of the research that has been, and is being, conducted or supported on reducing opioid usage following medical procedures described in subsection (a); (B) disaggregate such analysis according to whether the medical procedure is a short-term medical procedure or a long-term medical procedure; and (C) take into consideration— (i) the costs associated with using the best practices described in subsection (a) relative to the costs of not using such best practices; and (ii) the rates of addiction to opioids associated with using the best practices described in subsection (a) relative to the rates of addiction to opioids associated with not using such best practices; and (2) shall include analysis of— (A) gaps that have been identified by Federal officials with respect to the costs and rates described in clauses (i) and (ii) of paragraph (1)(C) relative to adult, young adult, and adolescent populations