1239-P: Trend in Total Payment and Out-of-Pocket Payment on a Yearly Supply of Oral Antidiabetic Drug Types among U.S. Adults with Private Health Insurance from 2003 to 2016

Increases in the number of new oral antidiabetic medications in the last decade have resulted in a change in payments. We examined the trends in total payment and patients’ out-of-pocket (OOP) payments on a yearly supply of various oral antidiabetic drug types from 2003 to 2016. We analyzed 1,803,427 adults with diabetes under fee for service plans from the 2003-2016 MarketScan commercial claims database. Antidiabetic drugs were grouped using National Drug Codes. Total and OOP payment for each drug type were modelled at a 30-day supply level, and later multiplied by 12 to obtain yearly estimates. Joinpoint regression was applied to identify the inflection point for trend changes and to estimate the magnitude of change in each defined segment. Payments were standardized to 2016 USD. Total payment for a yearly supply of newer drug types grew sharply after 2012, with an increasing rate of $334 (11%), $598 (10%), and $414 (11%) per year for DPP-4, GLP-1 and SGLT2, respectively (all p< 0.01). For older drugs, a decrease in total payment for a yearly supply was observed among Sulfonylurea (-$9,-6%), Meglitinide (-$595,-34%), AGI (-$71.41, -10%) and TZD (-$721,-48%) per year after 2012 (all p <0.01). Metformin is the only exception, which was found to have sharply increased at annual rate of $75 (32%, p<0.01) for a yearly supply. Although total payment escalated over time, OOP payment on most drug types remained during the study periods (all p-values >0.05). Only OOP payments on DPP-4, GLP-1, SGLT2 increased after 2010, but all below 5% per year and with p-values >0.05. Patterns of changes in payment on a yearly supply of drugs varied by drug type. Payment on older drugs tended to decline with exception of an increase for Metfomin. Payment increases on newer oral drugs tended to accelerate over time. OPP payments also varied by drug types but mostly declined over time, implying that the increase in payment for the newer drugs was mainly borne by payers.