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This is the primary outcomes article for CTN-0080-A-2. Introduction: Racial and ethnic inequities persist in medication treatment initiation and adherence for pregnant and postpartum people with opioid use disorder (OUD). Our objective was to understand the experiences of “positive outliers,” specifically pregnant and postpartum people of color with OUD who utilized medication treatment and engaged in a randomized clinical trial for buprenorphine despite historical, cultural, and structural barriers.

Methods: We conducted two sets of semi-structured qualitative interviews. First, trained peers with lived expertise as mothers in recovery interviewed individuals who identified with a non-white race and/or ethnicity and enrolled in the Medication Treatment for OUD in Expectant Mothers (MOMs) trial (NCT03918850). Second, we interviewed principal investigators, clinicians, and research coordinators from the 13 MOMs trial sites. We used an inductive thematic approach informed by the Social Ecological Model of Racism and Anti-Racism. Transcripts were double-coded and reviewed until consensus was reached. Preliminary findings from participant and staff interviews were merged and triangulated with peers to inform theme development.

Results: We completed 17 interviews with MOMs trial participants from 7 sites. Participants identified as Hispanic (29%), Black non-Hispanic (24%), multi-racial Hispanic (18%), multi-racial non-Hispanic (18%), and American Indian, Native Hawaiian, or Pacific Islander (12%). Thirty-two interviews with trial staff were also completed. Three themes emerged: (1) Although some participants expected racist treatment and research exploitation, all participants interviewed reported non-discriminatory, non-judgmental care within the MOMs trial; (2) Compassionate care, frequent, personalized, and integrated encounters, and emotional support helped counteract prior stigmatizing and discriminatory health care interactions, enabling participants of color to feel particularly supported, trusted, and empowered during the MOMs trial; and (3) Despite pervasive cultural stigma around addiction and concerns about taking an investigational drug while pregnant, participants expressed that pregnancy status, care team trust, and transparent communication with MOMs trial staff encouraged medication utilization and adherence.

Conclusion: Facilitators of successful engagement in the MOMs trial and retention in medication treatment among pregnant and postpartum people of color with OUD included non-judgmental care, sustained trust, and frequent contact. Key perinatal OUD clinical interventions and trial improvements include personalized communication and scheduling flexibility to promote engagement of marginalized populations.

Related protocols: CTN-0080-A-2

Objectives: Racial and ethnic differences in long-term outcomes associated with medications for opioid use disorder (MOUD) are poorly understood.

Methods: The present analyses were based on 751 participants with opioid use disorder (OUD) who were initially recruited from opioid treatment programs located in California, Connecticut, Oregon, Pennsylvania, and Washington and participated in a randomized controlled trial and at least one follow-up interview. 9.6% (n=72) of the participants self-identified as Non-Hispanic (NH) Black, 16.0% (n=120) Hispanic, and 74.4% (n=559) NH White. We tested racial and ethnic differences in psychiatric or social functioning, substance use and treatment participation.

Results: From the baseline to the end of follow-up interview, compared with NH White, Hispanic participants had a significantly greater proportion of months reporting any opioid use (45.5% vs. 32.5%, p<0.001) and a smaller proportion of months receiving any MOUD (47.7% vs. 58.1%; p<0.05), particularly receipt of buprenorphine treatment (8.3% vs. 14.9%; p<0.01). At the third follow-up interview, data from the Addiction Severity Index (ASI) indicated that Hispanic participants had greater severity in employment problems (0.72 vs. 0.58; p < 0.001), while Black participants had less severity in drug problems (0.11 vs. 0.16; p<0.05) compared to NH Whites.

Conclusions: The study found that Hispanic participants had higher rates of opioid use (heroin and prescription opioids), but few received MOUD (buprenorphine and methadone) during the follow-up period, which suggests that effective strategies are needed to increase access to MOUD among Hispanics. Additionally, addressing employment challenges might also help improve long-term outcomes for all populations with OUD.

Related protocols: CTN-0050

Racial and ethnic disparities in access to treatment and quality of treatment for opioid use disorder (OUD) have been identified in usual care settings. In contrast, disparities in treatment quality within clinical trials are relatively unexamined. This study aimed to estimate racial and ethnic differences in the dose of opioid agonist treatment for OUD in the first 4 weeks of treatment in clinical trials.

This cohort study performed analysis of the methadone and buprenorphine treatment arms of 3 trials conducted by the National Institute on Drug Abuse Clinical Trials Network between May 2006, and January 31, 2017, at multiple Clinical Trials Network sites across the US (CTN-0027, START, CTN-0030, POATS, and CTN-0051, X:BOT). Trial participants who were randomized to and initiated buprenorphine or methadone treatment and who identified as Hispanic, non-Hispanic Black, or non-Hispanic White were included in the present study. Data were analyzed from November 1, 2023, to August 5, 2024. THe main outcomes and measures were the maximum daily dose of buprenorphine or methadone received in each week for the first 4 weeks of treatment. The mean dose and percentage of patients receiving a higher dose (buprenorphine =16 mg and methadone =60 mg) were also compared across race and ethnicity groups.

A total of 1748 patients (1263 who initiated buprenorphine and 485 who initiated methadone treatment) were included in the analysis (1168 [66.8%] male; median age, 33 [IQR, 26-45] years). Of these, 138 patients (7.9%) identified as Black, 273 (15.6%) as Hispanic, and 1337 (76.5%) as White. In week 4, Black patients received buprenorphine doses 2.5 (95% CI -4.6 to -0.5) mg lower and methadone doses 16.7 (95% CI, -30.7 to -2.7) mg lower compared with White patients, after standardizing by age and sex. In week 4, the percentage of patients receiving a higher dose of medication (buprenorphine =16 mg; methadone =60 mg) was 16.9 (95% CI, -31.9 to -1.9) points lower for Black patients compared with White patients. Hispanic and White patients received similar buprenorphine doses; Hispanic patients received lower methadone doses than White patients.

Conclusions: In this cohort study of data from 3 clinical trials, White patients generally received higher doses of medication than Black patients. Future research is needed to understand the mechanisms of and interventions to reduce disparities in OUD treatment quality and how such disparities impact generalizability of trial results.

Note: An invited commentary piece on this article was also published by JAMA Network Open (Schiff DM, Nidey N, Tiako MJN. Dosing inequities in opioid use disorder treatment trials. JAMA Network Open 2024;7(10):e2436582.)

Related protocols: CTN-0027, CTN-0030, CTN-0051

There has been a significant increase in methamphetamine use and methamphetamine use disorder (Meth UD) in the United States, with evolving racial and ethnic differences. This secondary analysis of data from CTN-0069 (ADAPT-2) explored racial and ethnic differences in baseline sociodemographic and clinical characteristics as well as treatment effects on a measure of substance use recovery, depression symptoms, and methamphetamine craving among participants in a pharmacotherapy trial for Meth UD.

The ADAPT-2 trial (ClinicalTrials.gov number, NCT03078075; N=403; 69% male) was a multisite, 12-week randomized, double-blind, trial that employed a two-stage sequential parallel design to evaluate the efficacy of combination naltrexone (NTX) and oral bupropion (BUP) vs. placebo for Meth UD. Treatment effect was calculated as the weighted mean change in outcomes in the NTX-BUP minus placebo group across the two stages of treatment.

Of the 403 participants in the ADAPT-2 trial, the majority (65%) reported non-Hispanic White, while 14%, 11% and 10% reported Hispanic, non-Hispanic Black, and non-Hispanic other racial and ethnic categories respectively. At baseline non-Hispanic Black participants reported less severe indicators of methamphetamine use than non-Hispanic White. Treatment effects for recovery, depression symptoms and methamphetamine cravings did not significantly differ by race and ethnicity.

Conclusions: Although we found racial and ethnic differences at baseline, our findings did not show racial and ethnic differences in treatment effects of NTX-BUP on recovery, depression symptoms and methamphetamine cravings. However, our findings also highlight the need to expand representation of racial and ethnic minority groups in future trials.

Related protocols: CTN-0068

As overdose rates rise among non-White Americans, understanding barriers to substance use disorder (SUD) treatment access by race and ethnicity is important. This study explores self-reported barriers to SUD treatment by race and ethnicity in emergency department (ED) populations.

We conducted a secondary, exploratory analysis of a randomized trial of patients not seeking SUD treatment who endorsed active drug use at six academic EDs (CTN-0047). Responses to the Barriers to Treatment Inventory were compared by race, ethnicity, and drug severity, using 2 tests (N = 858), followed by adjusted logistic regression models.

Absence of a perceived drug problem (39% non-Hispanic Black, 38% Hispanic, 50% non-Hispanic White; p = .001) was the most prevalent barrier to SUD treatment. Non-Hispanic Black participants were less likely to state that they could handle their drug use on their own (OR = 0.69, CI = 0.50-0.95), and were more likely to report disliking personal questions than non-Hispanic White participants (OR = 1.49, CI = 1.07-2.09). Non-Hispanic Black participants were less likely than Hispanic participants to agree that treatment availability (OR = 0.46, CI = 0.28-0.76) and family disapproval (OR = 0.38, CI = 0.16-0.91) were treatment barriers.

Conclusions: Screening and counseling may help address the barrier, common to all groups, that drug use was not seen as problematic. Expanding access to diverse treatment options may also address the range of barriers reported by our study population. This study is one of the first in the U.S. to examine both individual and structural barriers to accessing treatment and to examine the association with drug use severity by race/ethnicity.

Related protocols: CTN-0047

The purpose of this study, part of NIDA-CTN-0117, was to examine changes in addiction medicine treatment utilization during the COVID-19 pandemic among adolescents (aged 13–17 years) and differences by race/ethnicity.

Researchers compared treatment initiation (overall and telehealth), engagement, and 12-week retention between insured adolescents with substance use problems during pre-COVID-19 (March to December 2019, n = 1,770) and COVID-19 (March to December 2020, n = 1,177) using electronic health record data from Kaiser Permanente Northern California.

Compared to pre-COVID-19, odds of treatment initiation, overall (adjusted odds ratio [95% confidence interval] = 1.42 [1.21–1.67]), and telehealth (5.98 [4.59–7.80]) were higher during COVID-19, but odds of engagement and retention did not significantly change. Depending on the outcome, Asian/Pacific Islander, Black, and Latino/Hispanic (vs. White) adolescents had lower treatment utilization across both periods. Changes in utilization over time did not differ by race/ethnicity.

Conclusions: Addiction medicine treatment initiation increased among insured adolescents during the pandemic, especially via telehealth. Although racial/ethnic disparities in treatment utilization persisted, they did not worsen.

Related protocols: CTN-0117

Addiction treatment rapidly transitioned to a primarily telehealth modality (telephone and video) during the COVID-19 pandemic, raising concerns about disparities in utilization. The objective of this study, part of CTN-0117, was to examine whether there were differences in overall and telehealth addiction treatment utilization after telehealth policy changes during the COVID-19 pandemic by age, race, ethnicity, and socioeconomic status.

This cohort study examined electronic health record and claims data from Kaiser Permanente Northern California for adults (age =18 years) with drug use problems before the COVID-19 pandemic (from March 1, 2019, to December 31, 2019) and during the early phase of the COVID-19 pandemic (March 1, 2020, to December 31, 2020; hereafter referred to as COVID-19 onset). Analyses were conducted between March 2021 and March 2023.

Generalized estimating equation models were fit to compare addiction treatment utilization during COVID-19 onset with that before the COVID-19 pandemic. Utilization measures included the Healthcare Effectiveness Data and Information Set of treatment initiation and engagement (including inpatient, outpatient, and telehealth encounters or receipt of medication for opioid use disorder [OUD]), 12-week retention (days in treatment), and OUD pharmacotherapy retention. Telehealth treatment initiation and engagement were also examined. Differences in changes in utilization by age group, race, ethnicity, and socioeconomic status (SES) were examined.

Among the 19 648 participants in the pre–COVID-19 cohort (58.5% male; mean [SD] age, 41.0 [17.5] years), 1.6% were American Indian or Alaska Native; 7.5%, Asian or Pacific Islander; 14.3%, Black; 20.8%, Latino or Hispanic; 53.4%, White; and 2.5%, unknown race. Among the 16 959 participants in the COVID-19 onset cohort (56.5% male; mean [SD] age, 38.9 [16.3] years), 1.6% were American Indian or Alaska Native; 7.4%, Asian or Pacific Islander; 14.6%, Black; 22.2%, Latino or Hispanic; 51.0%, White; and 3.2%, unknown race. Odds of overall treatment initiation increased from before the COVID-19 pandemic to COVID-19 onset for all age, race, ethnicity, and SES subgroups except for patients aged 50 years or older; patients aged 18 to 34 years had the greatest increases (adjusted odds ratio [aOR], 1.31; 95% CI, 1.22-1.40). Odds of telehealth treatment initiation increased for all patient subgroups without variation by race, ethnicity, or SES, although increases were greater for patients aged 18 to 34 years (aOR, 7.17; 95% CI, 6.24-8.24). Odds of overall treatment engagement increased (aOR, 1.13; 95% CI, 1.03-1.24) without variation by patient subgroups. Retention increased by 1.4 days (95% CI, 0.6-2.2 days), and OUD pharmacotherapy retention did not change (adjusted mean difference, -5.2 days; 95% CI, -12.7 to 2.4 days).

Conclusions: In this cohort study of insured adults with drug use problems, there were increases in overall and telehealth addiction treatment utilization after telehealth policies changed during the COVID-19 pandemic. There was no evidence that disparities were exacerbated, and younger adults may have particularly benefited from the transition to telehealth.

Related protocols: CTN-0117

There are a wide variety of methods for using combustible cannabis which may impact an individual’s pattern of use as well as their response to cannabis use disorder (CUD) treatment. Previous research has noted racial/ethnic differences in cannabis users’ preferred method of use.

This study examined data from a randomized placebo-controlled trial of a pharmacological intervention for adults with CUD (CTN-0053). Latent profile analysis classified participants (N=302) based on their primary method of combustible cannabis use.

A four profile solution emerged that identified participants who demonstrated 1) Primarily Joint (n=50), 2) Primary Blunt (n=106), 3) Mixed Method of Use (MoU; n=30), and 4) Primarily Pipe (i.e. pipe or bong; n=116) use. Profiles were compared on socio-demographic characteristics and racial differences were found among the four latent profiles as well as differences in their level of use. Cannabis users with a preference for joints were more likely to be White as compared to other racial groups. In contrast, a greater proportion of participants with a preference for blunts were African American. The Primarily Joint profile was found to have the highest cannabis relapse rate at 1-month follow-up (94%) which was significantly greater than the Mixed MoU (74%) and Primarily Pipe (78%) profiles. Interestingly, there was no difference in 1-month follow-up cannabis relapse rates between the Primarily Joint and Primarily Blunt profiles (87%).

Conclusions: Findings suggest that treatment-seeking individuals who primarily use joints or blunts may face unique challenges that may impact cannabis abstinence. Along with other cannabis-related characteristics, an individual’s preferred method of use may represent an important factor to consider in the treatment of CUD.

Related protocols: CTN-0053

Research studies suggest racial/ethnic differences in posttraumatic stress disorder (PTSD) diagnosis and symptom severity. Few studies to date, however, have examined the extent to which these findings are due to differences in measurement properties of existing PTSD scales. This study examined measurement equivalence across race/ethnicity in the Clinician-Administered PTSD Scale (CAPS) by testing for differential item functioning (DIF) in the item response theory (IRT) framework.

Participants were 506 trauma-exposed women (M=39.41 years), who participated in the NIDA Clinical Trials Network Women and Trauma study (CTN-0015). PTSD severity score estimates were improved upon as part of IRT estimation incorporating symptom “weights” (i.e., factor loadings) and group-specific DIF. Six symptoms from the CAPS showed DIF, with the majority of differences in measurement driven by White/African Americans and White/Latina differences, particularly for (a) avoidance of thoughts and (b) a sense of foreshortened future. Despite both racial/ethnic minority groups being slight (not significantly) more likely to receive a PTSD diagnosis, African Americans and Latinas had significantly lower PTSD severity scores than Whites as estimated under IRT with group-specific DIF. Examination of PTSD severity scores based on symptom counts revealed these differences were either dampened or entirely negated.

Conclusions: These findings suggest the importance of considering differences in symptom relevance across race/ethnicity and their impact on capturing symptom severity parallel to diagnostic criteria. Implications for clinical practice are discussed.

Related protocols: CTN-0015

Hispanics significantly underutilize substance abuse treatment and are at greater risk for poor treatment outcomes and dropout. Two decades of research from the National Drug Abuse Treatment Clinical Trials Network (CTN) offers an opportunity to increase our understanding in how to address the disparities experienced by Hispanics in substance abuse treatment.

A scoping review was utilized to determine what has been learned from the CTN about Hispanic populations with substance use disorder. A systematic search was conducted within the CTN Dissemination Library and nine databases. Potentially relevant studies were independently assessed by two reviewers for inclusion.

Twenty-four studies were included in the review. Results identified issues in measurement, characteristics of Hispanic substance use, effective interventions, and gaps for future research. Characteristics that interfere with treatment participation were also identified including low employment rates, less likelihood of having insurance, lower rates of internet access, and increased travel time to services, as were treatment issues such as high rates of alcohol and tobacco use. Effective interventions were identified; however, the effectiveness of these interventions may be limited to specific factors.

Conclusions: Despite efforts to improve inclusion of minority populations, Hispanics remain underrepresented in clinical trials. Future research including Hispanic populations should examine measurement equivalence and consider how cultural and historical experiences, as well as patient characteristics, influence utilization of services. Finally, more studies are needed that examine the impact of structural factors that act as barriers to treatment access and engagement and result in significant disparities in treatment outcomes.

A critical strategy to address the opioid epidemic is increasing access to pharmacotherapy, particularly buprenorphine/naloxone (BUP). BUP is a partial agonist that has a superior safety profile than methadone (MET), a full agonist, in terms of overdose risk. Few studies have compared the long-term outcomes of participants randomized to BUP or MET treatment for opioid use disorder (OUD), however, and differences in treatment retention by medication type may translate into variation in criminal justice outcomes.

This study aimed to compare long-term criminal justice outcomes among opioid dependent individuals randomized to receive buprenorphine or methadone. Five-year follow-up was conducted in 2011-2014 of 303 opioid-dependent participants entering three opioid treatment programs in California in 2006-2009 (as part of CTN-0050, “Starting Treatment with Agonist Replacement Therapy (START)”) and randomized to receive either buprenorphine/naloxone or methadone.

Participants received BUP (n=179) or MET (n=124) for 24 weeks and then were tapered off their treatment over 8 weeks or less or referred for ongoing clinical treatment. Midway through the study, the randomization scheme was switched from 1:1 BUP:MET to 2:1 because of higher drop out in the BUP arm.

Study outcomes included arrests and self-reported incarceration. Predictors included randomization condition (BUP vs. MET), age, gender, race/ethnicity, use of cocaine, drug injection in the 30 days prior to baseline, and study site. Treatment status (BUP, MET, none) during follow-up was included as a time-varying covariate.

There was no significant difference by randomization condition in the proportion arrested (BUP: 55.3%, MET: 54%) or incarcerated (40.9%, 47.3%) during follow-up. Among methadone-randomized individuals, arrest was less likely with methadone treatment (0.50, 0.35-0.72) during follow-up (relative to no treatment) and switching to buprenorphine had a lower likely likelihood of arrest than those receiving no treatment (0.39, 0.18-0.87). Among buprenorphine-randomized individuals, arrest was less likely with receipt of buprenorphine (0.49, 0.33-0.75) during follow-up and switching to methadone had a similar likelihood of arrest as methadone-randomized individuals receiving no treatment. Likelihood of arrest was also negatively associated with older age (0.98, 0.96-1.00); it was positively associated with Hispanic ethnicity (1.63, 1.04-2.56), cocaine use (2.00, 1.33-3.03), injection drug use (2.19, 1.26-3.83), and study site.

Conclusions: In a US sample of people treated for opioid use disorder, continued treatment with either buprenorphine or methadone was associated with a reduction in arrests relative to no treatment. Cocaine use, injection drug use, Hispanic ethnicity, and younger age were associated with higher likelihood of arrest.

Related protocols: CTN-0050

There are higher rates of menthol cigarette smoking within certain population subgroups. Limited research has examined menthol use among individuals in treatment for substance use disorders (SUD), a population with a high prevalence of cigarette smoking, poor smoking cessation outcomes, and high tobacco disease burden.

To try to fill that research gap, this study collected survey data from 863 smokers sampled from 24 SUD treatment programs affiliated with the NIDA Clinical Trials Network (CTN) in the United States. Prevalence of menthol cigarette smoking was examined for the sample. Bivariate and multivariable analyses were used to examine demographic and tobacco use characteristics associated with menthol cigarette smoking.

Overall, the prevalence of menthol smoking among individuals in SUD treatment was 53.3%. Smoking menthol versus non-menthol cigarettes was associated with being female, African American, Hispanic/Latino, and lower odds of having a college degree. Controlling for demographic factors, menthol smokers were more likely to report marijuana as their primary drug compared to alcohol. Lastly, menthol smokers were more likely to report interest in getting help for quitting smoking, although they were not more likely to report making a past year quit attempt.

Conclusions: Use of menthol cigarettes was higher among smokers in SUD treatment than in general population smokers. Menthol cigarette smoking may contribute to tobacco use disparities among individuals with SUD. Regulatory policies targeting the manufacture, marketing, or sale of menthol cigarettes may benefit vulnerable populations, including smokers in SUD treatment.

Differences in tobacco use behaviors have been identified between Latinos and non-Latino whites in the general US population. Little is known about cigarette smoking and quitting behaviors of Latinos in treatment for substance use disorders (SUDs), who represent two major tobacco-vulnerable groups. This study aimed to compare, in a national sample of persons enrolled in SUD treatment, demographic, drug use, and smoking and quitting prevalence and behaviors between Latinos and non-Latino whites. Researchers surveyed 777 SUD treatment clients, sampled from 24 clinics selected at random from the NIDA Clinical Trials Network (Latino client n=141; 40% female). Univariate and multivariate analyses were then conducted to identify correlates of smoking behaviors by Latino/non-Latino white ethnicity.

Latinos’ smoking prevalence resembled that of non-Latino whites (78.7% vs. 77.4%). In regression analyses, Latino smokers (n=111) tended to smoke fewer cigarettes per day (CPD) than non-Latino white smokers (n=492), were more often nondaily smokers and menthol smokers, more often reported a smoking quit attempt in the last year, and tended to report higher numbers of past-year quit attempts. Among Latino smokers, those with less education and those reporting opioids as their primary drug of use reported higher CPD.

Conclusions: Latinos in SUD treatment are at equally high risk of being current heavy smokers as compared to non-Latino whites in SUD treatment. At the same time, Latinos in SUD treatment exhibit ethnic-specific smoking and quitting behaviors that should be considered when designing smoking interventions for this group. Ethnic minorities and persons with SUDs are treated within health policy and scientific literature as distinct groups with specific risk factors for tobacco use and related disease, but in everyday life individuals occupy more than one social category. Thus, tobacco cessation efforts must confront multiple sources of risk and inequality to reach intersectional populations such as Latinos with SUDs. The findings presented here not only attest to the complexity of such efforts, but also signal their necessity.

The Therapeutic Education System (TES), an Internet version of the Community Reinforcement Approach plus prize-based motivational incentives, is one of few empirically supported technology-based interventions. To date, however, there has not been a study exploring differences in substance use outcomes or acceptability of TES among racial/ethnic subgroups. This study uses data from a multisite (N=10) effectiveness study of TES to explore whether race/ethnicity subgroups (White [n=267], Black/African American [n=112], and Hispanic/Latino [n=55]) moderate the effect of TES. Generalized linear mixed models were used to test whether abstinence, retention, social functioning, coping, craving, or acceptability differed by racial/ethnic subgroup. Findings demonstrated that race/ethnicity did not moderate the effect of TES versus TAU on abstinence, retention, social functioning, or craving. A three-way interaction (treatment, race/ethnicity, and abstinence status at study entry) showed that TES was associated with greater coping scores among non-abstinent White participants (p=.008) and among abstinent Black participants (p<.001). Acceptability of the TES intervention, although high overall, was significantly different by race/ethnicity subgroup with white participants reporting lower acceptability of TES compared to Black (p=.006) and Hispanic/Latino (p=.008) participants.

Conclusions: Findings from this study lend additional support for the use of technology-based interventions in the treatment of substance use disorders. The acceptability of Internet-delivered interventions among racial/ethnic minority populations suggests promise for increasing access to services and reducing disparities in treatment outcomes. In this large multisite national study, racial/ethnic subgroups received similar benefit from Internet-based CRA/CM and reported high rates of acceptability, with Black participants reporting the highest rates of acceptability. TES should be considered as an additional tool to support usual care in outpatient treatment programs among diverse subgroups of patients.

Related protocols: CTN-0044

The current study examined differences in substance abuse treatment outcomes among racial and ethnic groups enrolled in the Stimulant Reduction Intervention using Dosed Exercise (STRIDE) trial, a multisite randomized clinical trial implemented through the National Institute on Drug Abuse’s (NIDA’s) Clinical Trials Network (CTN). STRIDE aimed to test vigorous exercise as a novel approach to the treatment of stimulant abuse compared to a health education intervention. A hurdle model with a complier average causal effects (CACE) adjustment was used to provide an unbiased estimate of the exercise effect had all participants been adherent to exercise.

Among 214 exercise-adherent participants, we found significantly lower probability of use for Blacks (z= -2.45, p=.014) and significantly lower number of days of use for Whites compared to Hispanics (z= -54.87, p=<.001) and for Whites compared to Blacks (z= -28.54, p=<.001), which suggests that vigorous, regular exercise might improve treatment outcomes given adequate levels of adherence.

Conclusions: The STRIDE study demonstrated that intensive exercise interventions for people with stimulant use disorders, in community-based addiction treatment, are feasible. Examining race/ethnicity differences in treatment outcomes using novel approaches is important to understanding disparities and what contributes to success. There is a need for engagement strategies for sustaining Blacks in treatment and recruiting them into treatment earlier in life. Vigorous exercise may benefit racial and ethnic minority populations with stimulant use disorder. Future research should focus on intentional inclusion of race/ethnic groups, early in the study design, to test interventions targeted with a specific focus on what works for certain populations.

Related protocols: CTN-0037