Objectives: This study assesses treatment initiation and retention among South Carolina Medicaid enrollees newly diagnosed with opioid use disorder in 2021, situating these outcomes within the broader opioid treatment cascade of care. We examine how patient characteristics and community context shape progression through the stages of the cascade. Methods: Using South Carolina Medicaid claims data for 464,493 enrollees aged 18–64 in 2021, we identify 2930 individuals newly diagnosed with OUD and examine initiation and 90-day retention in psychosocial and medication treatment. Generalized estimating equation models were used to estimate associations between treatment outcomes and sociodemographic and area-of-residence characteristics. Results: Among newly diagnosed individuals, 34.6% initiated psychosocial treatment and 49.6% initiated medication treatment; 27.0% and 55.0%, respectively, were retained for at least 90 days. Non-Hispanic black enrollees had lower odds of initiating psychosocial (AOR = 0.72; 95% CI = 0.54–0.96) and medication treatment (AOR = 0.51; 95% CI = 0.44–0.58) compared with non-Hispanic white enrollees. Age differences were pronounced: enrollees aged 25–34 were more likely to initiate psychosocial treatment (AOR = 1.16; 95% CI = 1.00–1.35), while those aged 35–44 were more likely to initiate and retain medication treatment. Associations between treatment outcomes and county-level factors were not significant. Conclusions: Rates of OUD treatment initiation and retention among South Carolina Medicaid enrollees remain low, with pronounced demographic variations. Findings highlight the need for targeted interventions to improve access and engagement in treatment.
Gross et al. (2026) studied this question.