Access to Substance Use Disorder Treatment and Use of Acute Care Among Medicaid Enrollees in South Carolina

Background and Objectives: Nationally, only about half of outpatient substance use disorder (SUD) treatment programs in the U.S. accept Medicaid. This finding has raised concerns that Medicaid enrollees who need SUD treatment may have difficulty locating a program willing to accept them. However, no studies have examined the impact of SUD treatment program acceptance of Medicaid on enrollee outcomes. The purpose of this study is to determine whether the proportion of county SUD treatment programs that accept Medicaid is associated with the frequency of acute care services related to substance use. Findings from this study have the potential to inform policy and practice to increase the availability of Medicaid-funded OSAT.

Methods: Data included all treatment episodes for Medicaid enrollees (n=3,564) who initiated an acute care episode (emergency and inpatient hospitalization) related to substance use in South Carolina hospitals from January 1, 2012 to December 31, 2013. We also measured the proportion of SUD treatment programs in each county that accept Medicaid using the 2012 National Survey of Substance Abuse Treatment Services. Using t-tests, we compared the average number of acute care episodes related to substance use in counties in with one, two, and three SUD treatment programs accept Medicaid. We used multilevel regression (accounting for within-county effects, n=46) with a Poisson distribution to assess the relationship between the total number of treatment programs accepting Medicaid by county and the number of acute care episodes related to substance use, accounting for patient, treatment, and system factors. Model results are reported as incident risk ratios (IRR).

Results:  We found that Medicaid enrollees who lived in counties with two SUD treatment programs that accept Medicaid had fewer episodes of acute care related to substance use during the study period than Medicaid enrollees in counties with only a single program (IRR = 0.68, p < 0.01). The reduction in the incident risk ratio was even stronger for Medicaid enrollees who lived in counties with three SUD treatment programs that accept Medicaid, relative to enrollees who live in a county with only one (IRR = 0.56, p < 0.01). Age (IRR = 1.01, p < 0.01), rural status (IRR = 1.23, p < 0.01), and admission for alcohol use (IRR = 1.12, p < 0.01) were positively associated with the number of episodes of acute care related to substance use.

Conclusions and Implications:  In South Carolina counties in which Medicaid enrollees had more SUD treatment options, they were less likely to require and receive acute care related to substance use. Further research is needed to assess whether use of SUD treatment by Medicaid enrollees in mediates this relationship. In light of the dramatic expansion of Medicaid under the Affordable Care Act, it is more important than ever to ensure that Medicaid enrollees who need SUD treatment have access to programs in their local communities that accept Medicaid.  Our findings suggest that access to SUD treatment among Medicaid enrollees may be linked to lower utilization of acute care related to substance use.