Costs of substance use disorders from claims data for Medicare recipients from a population-based sample

Medicare spending is projected to increase over the next decade, including for substance use disorders (SUD). Our objective was to determine whether SUDs are associated with higher six-year Medicare costs (1999-2004) among participants in the Baltimore Epidemiologic Catchment Area (ECA) Study. Medicare claims data for the years 1999-2004 from the Centers for Medicare and Medicaid Services were linked to four waves of data from the Baltimore ECA cohort collected between 1981 and 2005 (n=566). A generalized linear model with a log link and gamma distribution was used to examine direct Medicare costs associated with SUD status. Medicare recipients with no history of SUD had mean six-year costs of $42,576. Those with a history of SUD based on both Baltimore ECA and Medicare data, or based on Medicare claims data alone, had significantly higher costs ($98,754 and $64,876, respectively). A history of SUD based solely on Baltimore ECA data alone had lower average costs ($25,491). Findings indicate that Medicare costs differ by source of SUD diagnosis when comparing treatment versus survey data. This may have future implications for projecting Medicare costs among SUD individuals as healthcare coverage expands under the Affordable Care Act.