While substance use disorder (SUD) treatment substantially improves health outcomes among people who use drugs, SUD treatment access and retention in care remain low in the United States (US). According to the 2021 National Survey on Drug Use and Health, only 6.3 % of the 46.3 million people aged 12 or older who met the criteria for drug or alcohol use disorder received treatment in the prior year (SAMHSA, 2022). Systemic barriers to SUD treatment are persistent and impede treatment initiation (Farhoudian et al., 2022); however, even when treatment is accessed, a sizable proportion of patients discontinue treatment prematurely, with about 30 % of discharge episodes in 2021 attributed to drop out or termination (SAMHSA, 2023). For example, in Rhode Island, only 51 % of treatment episodes involving medication for opioid use disorder (MOUD) lasted more than 6 months and only 58 % of patients discharged from substance use treatment in 2018 completed treatment (Daly and Gargano, 2021, Krawczyk et al., 2021, Andraka-Christou et al., 2022).

Although research has shown that recurrent drug use is a common characteristic of recovery progress, many SUD treatment programs still prioritize abstinence from all drugs during treatment and require participants to provide negative urine tests as a condition of treatment continuation (Paquette et al., 2022, White et al., 2005). This treatment approach is associated with worse quality of care and forced treatment termination (Williams and Bonner, 2020). For the purposes of this study, forced treatment discontinuation is defined as premature discharge from substance use treatment programs by providers or administrators, and is distinct from successful completion of treatment or client-initiated treatment termination. Forced treatment discontinuation is associated with adverse health outcomes, such as increased hospitalizations, emergency department visits, and greater risk of mortality post-discontinuation (Degenhardt et al., 2009, Hasan et al., 2022, Mitchell et al., 2011; Williams et al., 2020). Thus, premature and forced treatment discontinuation may deepen and exacerbate health disparities among people who use drugs, and identifying subgroups most affected by forced treatment discontinuation is essential to address disparities in treatment retention and treatment duration.

While prior research has examined the factors associated with treatment retention among people who use drugs (Daly and Gargano, 2021, Hubbard et al., 2003, McCaul et al., 2001, Stafford et al., 2022, Brorson et al., 2013, Daigre et al., 2021, Krawczyk et al., 2021), there has been relatively less attention paid to the factors correlated with forced treatment discontinuation due to recurrent drug or alcohol use. Features of SUD treatment program, such as program type, and the reasons for forced discontinuation have also been relatively unexplored in studies examining treatment retention (Daigre et al., 2021, McCaul et al., 2001, Andraka-Christou et al., 2022, Krawczyk et al., 2021). To address these gaps, this study aims to: (1) examine differences in sociodemographic, drug use, and clinical characteristics between those who were forced to discontinue treatment due to substance use and those who were not; (2) describe the features of programs (e.g., program type) from which participants were forcibly terminated, as well as the substances that were implicated in forced treatment discontinuation; and (3) identify those factors that are independently associated with forced treatment discontinuation.