Integrating Evidence-Based Methamphetamine Interventions into Methadone Clinics: Structural Barriers and Implementation Opportunities

Abstract

Background

Integrating evidence-based methamphetamine interventions into methadone programs is critical to address increasing methamphetamine use among methadone patients. This study examined the barriers and facilitators of implementing such integration in Vietnam.

Method

We conducted a qualitative study nested within an adaptive trial, Screen, Treat and Retain Meth-Using People with Opioid Use Disorder in Methadone Clinics (STAR-OM), integrating evidence-based methamphetamine interventions into 15 methadone clinics. Seventy-six in-depth interviews were conducted with participants and methadone providers to seek their experience implementing or receiving the study interventions. Interview guides were based on the Consolidated Framework for Implementation Research. Data was analyzed using thematic analysis to identify and explore key themes.

Results

Results reflected a tension between strong clinical support for integrating methamphetamine interventions and substantial structural constraints. The main facilitator was the perceived impact of interventions driven by social accountability and engagement with peers, providers and family members. Key barriers operated primarily at structural levels and included: (1) restrictive policy environments despite local demand for intervention; (2) workforce precarity and limited financial resources, particularly for contingency management; and (3) logistical implementation challenges such as organizing group sessions, burdensome urine testing, falsified urine samples and limited use of SMS-based reminders.

Conclusion

While evidence-based methamphetamine interventions were widely perceived as beneficial, major barriers existed at the policy and program levels. Macro-level actions – such as advocating for more harm reduction – oriented drug policies and strengthening workforce capacity – alongside pragmatic, clinic-level implementation strategies are essential for the sustainable adoption and scale-up of evidence-based methamphetamine interventions within Vietnam’s methadone program.

INTRODUCTION

The global increase in methamphetamine use jeopardizes the ongoing efforts to combat the dual epidemics of opioid use disorder (OUD) and HIV infection (Feelemyer et al. 2020). Methamphetamine use is associated with increased sexual HIV risk behaviors, lower engagement in OUD treatment among people with primary OUD, and greater discontinuation of OUD treatment among people in treatment (Frost et al. 2021; Zhang et al. 2017). For people living with HIV, it decreases retention in HIV care, hinders adherence to HIV treatment, and accelerates HIV disease progression (Carrico, Cherenack, et al. 2018; Carrico et al. 2019; Carrico, Flentje, et al. 2018). Methamphetamine use is particularly prevalent in Vietnam and other Southeast Asian countries (UNODC Regional Office for Southeast Asia and the Pacific 2025). Recent cross-sectional studies in Vietnam indicated that about 25% of people with OUD in methadone treatment were using methamphetamine, and almost 80% of them were at moderate or high risk methamphetamine use, defined using the WHO Alcohol, Smoking and Substance Involvement Screening Test (ASSIST) (moderate risk: scores 4–26; high risk: scores ≥ 27) (Giang, Li, et al. 2022; Le et al. 2021). This signals the need for integration of adapted evidence-based interventions (EBIs) into routine methadone services to reduce methamphetamine use in this population.

Behavioral EBIs, including motivational interviewing, contingency management, the Matrix model, and short message service (SMS) text messaging have proved their effectiveness to reduce methamphetamine use, although the evidence base of the EBIs has been mainly established in Western, non-methadone settings (AshaRani et al. 2020; Brown and DeFulio 2020; Ginley et al. 2021; Knight et al. 2019; Radfar and Rawson 2014; Reback, Fletcher, and Kisler 2021; Reback, Fletcher, and Leibowitz 2019). Motivational interviewing is a counseling approach designed to boost individuals’ motivation for behavior change (Miller and Rollnick 2002). Contingency management strengthens behavior change by incentivizing health-promoting behaviors such as reduced substance use or treatment adherence with rewards (Brown and DeFulio 2020). The Matrix model is a structured approach blending various aspects of cognitive behavioral therapy, including education and relapse prevention skills development (Rawson et al. 2004). The SMS method uses theory-based text messages to provide individuals with information relating to harm reduction, treatment adherence, and social support and self-monitoring opportunities (Reback, Fletcher, Swendeman, et al. 2019; Reback et al. 2021). Contingency management has the strongest evidence for effectiveness across socioeconomic groups and is recommended as a first-line treatment for stimulant use disorders in recent clinical guidelines (AshaRani et al. 2020; Clinical Guideline Committee (CGC) Members et al. 2024; Secades-Villa et al. 2013). Integrating these EBIs into OUD treatment is needed to ensure optimal treatment outcomes for participants with concurrent opioid and methamphetamine use disorders.

From 2020 to 2025, we implemented the randomized controlled trial, “Screen, Test and Retain People with Opioid Use Disorder Who Use Methamphetamine in Methadone Clinics (STAR-OM) (Giang et al. 2023; Giang, Trang, et al. 2022). The trial aimed to identify optimal combinations of EBIs to improve HIV and substance use outcomes among people with OUD who concurrently use methamphetamine and receive methadone treatment in Vietnam, while exploring factors influencing the adoptions of these EBI in real-world methadone programs.

The intervention lasted 24 weeks, during which participants underwent twice weekly random urine drug screening (Giang, Trang, et al. 2022). During the first 12 weeks (frontline interventions), participants were randomized to receive either a high-intensity frontline intervention consisting of 12 weeks of contingency management, or a low-intensity frontline intervention consisting of 6 weeks of contingency management followed by 6 weeks of group education. During the second 12 weeks (adaptive strategies), responders to the frontline interventions – defined as participants who tested negative for methamphetamine in 4 consecutive tests during Weeks 11 and 12 – received daily SMS text messages. Non-responders were randomized again to receive either Matrix group counseling alone or Matrix group counseling plus contingency management.

Vietnam’s methadone program has operated nationwide since 2010 (Nguyen et al. 2012). As of early 2024, 343 clinics served about 50,000 people with OUD (Vietnam Administration of AIDS Control 2024). However, the program’s potential impact has been constrained by an abstinence-focused policy requiring discontinuation of methadone treatment after a single positive test for nonopioid drugs such as methamphetamine during the maintenance phase (Government of Vietnam 2016). Legal consequences intensified on July 1^st, 2025, when the Revised Penal Code introduces incarceration for individuals who test positive for illicit drugs while receiving methadone treatment (National Assembly of Vietnam 2025). In this policy environment, identifying barriers and facilitators for integrating evidence-based methamphetamine interventions becomes more critical to better support participants receiving methadone with concurrent methamphetamine use.

METHOD

Study setting

The study was conducted across 15 methadone clinics in Hanoi and Ho Chi Minh City (HCMC) – two cities with the largest methadone treatment populations, where the prevalence of methamphetamine use among people receiving methadone treatment ranged from 25% to 35% (Giang, Li, et al. 2022; Le et al. 2021). All methadone patients attending these clinics were approached and screened for eligibility. Inclusion criteria included age ≥ 16 years and either a positive urine test result with methamphetamine or a score of ≥ 10 for methamphetamine use on ASSIST (Giang, Trang, et al. 2022). Study drug testing was conducted separately from routine clinical testing: urine samples were collected and processed by research staff, and results were not shared with clinic staff or used to inform methadone treatment decisions. Therefore, positive methamphetamine results generated by the study did not affect participants’ eligibility to continue methadone treatment. A total of 667 participants were enrolled and the STAR-OM intervention model demonstrated promising outcomes in reducing methamphetamine use (Giang et al. 2026).

Conceptual framework

We used the Consolidated Framework for Implementation Research (CFIR) to guide our study throughout data collection and analysis (Damschroder et al. 2009, 2022). CFIR includes unique and common elements of 19 different theories, models, and frameworks (Damschroder et al. 2009). The framework consists of 5 major domains including a) innovation, b) outer setting, c) inner setting, d) characteristics of individuals and e) implementation process (Reardon et al. 2025). We used these domains to structure the interview guides and ensure that interviews captured factors at multiple levels of implementation. CFIR also informed the initial coding framework. Data were synthesized across CFIR domains to develop themes.

Data collection

At pre-intervention, we purposively selected an initial qualitative sample to ensure representation across clinics, frontline intervention conditions for participants with OUD, and staff positions among providers, including counselors, physicians, laboratory technicians, clinic heads and district health center leaders. For the post-intervention interviews, we recruited additional participants with OUD and providers to replace those who had withdrawn from or moved out of the study and to ensure sufficient representation of experiences with each EBI delivered during the trial. Recruitment continued until saturation was reached for topics related to barriers and facilitators to EBI adoption. This report is based on the final post-intervention sample of 35 participants with OUD and 41 providers.

Interviews were conducted in a private room in participants’ clinics. They explored participants’ overall feedback on the intervention model, and on specific interventions, perceived barriers and facilitators to implementation, feasibility and suggestions for scale-up.

Each interview began with an open-ended question about general impression: “Please let us know how you experience the last six months of intervention.” Follow-up probes included: “What do you see as the main achievements? What have been the main challenges?” Subsequent questions explored specific interventions, such as: “What are your thoughts on contingency management?” or “How did participants receive the Matrix sessions?” To examine scalability and sustainability, we asked questions including: “How feasible would it be for methadone clinics to adopt these interventions as they are in routine practice?” and “What changes would be needed to integrate these interventions in methadone settings?” (see the Appendix for the complete interview guides).

Three PhD-level interviewers with extensive experience in qualitative study and substance use issues in Vietnam conducted all interviews. Interviewers had no prior relationship with participants with OUD but had professionally known some providers before the interviews. The median interview duration was 62 minutes (IQR: 43–80). Participants received VND 200,000 (~US$9) as a compensation for their time.

Data analysis

All interviews were audio-recorded and transcribed verbatim. After each interview, the interviewers noted key highlights and arising questions to explore with subsequent interviews. We used thematic analysis with a combined deductive and inductive analytic approach (Braun and Clarke 2021). Initial codes were created from interview guides and included codes such as “clinic functioning”, “clinic workforce” and “perceived feasibility”. Additional codes that emerged from the data, such as “motivational effects of frequent testing” and “regulatory limitations” were added during the coding process.

The coding team comprised seven researchers and research assistants with in-depth familiarity with the intervention and clinic context. Coders all had at least a master’s degree in health-related disciplines. The team initially met to establish a shared understanding of each code. Each coder independently coded one participant with OUD and one provider transcript. The team reviewed these coded transcripts together, discussed discrepancies and refined code definitions as needed. Once consensus was achieved, the remaining transcripts were coded by one team member each. Throughout the coding process, the team met weekly to review emerging codes, resolve coding questions and discuss preliminary interpretations. Upon completion of coding, data within each code were summarized and arranged into four themes representing the facilitators and barriers to the integration of methamphetamine interventions into routine methadone services. We used Atlas.ti version 25.0.1 (Atlas.ti 2024) to assist the analysis.

The Institutional Review Boards of Hanoi Medical University and the University of Medicine and Pharmacy at HCMC approved the study protocols, informed consent forms, and interview guides on 8 June 2020 (#122-GCNHDDDNCYSH-DHYHN) and 1 July 2020 (#433-HDDDDHYD), respectively. All participants have provided their written consent for study participation.

RESULTS

Table 1 presents participants’ sociodemographic characteristics. Among participants with OUD, 42% were female, and the median age was 40 years (IQR: 37–42.5). They had been receiving methadone for a median of 6 years (IQR: 4–9.8). Half (49%) were married or living with a partner. Educational attainment was generally low, with over half (51%) completing middle school or less. Most participants (78%) reported unstable employment, while 11% were unemployed and 11% had stable income.

Table 1.

Participant characteristics

	Participants with OUD (n=35)		Methadone providers (n=41)
	N	%	N	%
Gender
Female	14	42	24	59
Male	21	58	17	41
Age (median, IQR)	40 (IQR: 37–42.5)		40 (IQR: 36–44)
Number of years receiving/providing methadone treatment (median, IQR)	6 (IQR: 4–9.8)		7 (IQR: 5–10)
Marital status
Married/Living with a sexual partner	17	49	35	85
Single/Divorced/Widowed	18	51	6	15
Educational attainment
Primary school	6	17	0	0
Middle school	12	34	0	0
High school	15	43	0	0
College or higher	2	6	41	100
Employment
Unemployed	4	11
Employed with stable income	4	11
Employed with unstable income	27	78
Frontline intervention
12-week CM	16	46
6-week CM + 6-week group education	19	54
Adaptive strategies
Matrix	10	29
Matrix + CM	6	17
SMS	19	54
Position in methadone clinics
Community health center leader			2	5
Clinic head/Treating physician			14	34
Counselor			15	37
Lab technician			9	22
Admin staff			1	2

Regarding frontline intervention exposure, 46% were enrolled in the 12-week contingency management condition and 54% in the combined 6-week contingency management plus 6-week group education condition. For adaptive strategies, most participants received daily SMS over the second 12 weeks, while 29% participated in the Matrix model and 17% in the Matrix plus contingency management.

Methadone providers were predominantly female (59%) with a median age of 40 years (IQR: 36–44) and had been providing methadone services for a median of 7 years (IQR: 5–10). Their roles included clinic heads or treating physicians (34%), counselors (37%), laboratory technicians (22%), district health center leaders (5%), and administrative staff (2%).

Below we present the facilitators and barriers to integrate methamphetamine intervention into methadone clinics. The perceived impact of the interventions emerged as a key facilitator, while barriers remained at policy, programmatic, and logistical implementation levels. The first and the fourth themes were salient across both participants with OUD and providers while the second and third themes were salient mainly among providers.

Perceived intervention impact through social accountability and engagement

The interventions were well received by participants with OUD and were widely perceived by both participants with OUD and providers as helpful and relevant to participants’ needs. Their positive impact appeared to be driven by mechanisms of social accountability and social engagement with peers, providers and family members.

Both participants with OUD and providers identified contingency management as the most motivating intervention for staying abstinent from methamphetamine.

When I had just joined, I still had cravings and urges. But I didn’t want to lose my points, so I tried hard, and managed to quit until now.

(Participant with OUD, female, 40 years old, temporary worker)

While the incentives in contingency management was a strong motivating factor, participants also described a strong desire to avoid disappointing providers or appearing irresponsible in front of others, suggesting that accountability within the treatment setting was another driver of change.

When the test is positive—I suddenly feel embarrassed. Nobody does anything to me, but I still feel ashamed.

(Participant with OUD, male, 47 years old, motorbike taxi driver)

Participants highly valued motivational interviewing sessions because they felt listened to and respected. In a context where stigma towards people who use drugs was prevalent (Trang et al. 2020, 2022), these sessions created a safe space where they could share openly, which many described as empowering:

We are often stigmatized and avoided, so we have many things bottled up. We don’t know who to talk to. When the counselors ask, I can open up, and they really listen.

(Participant with OUD, female, 29 years old, shop assistant)

While not all participants found SMS messages beneficial, some appreciated them as reminders that someone cared about their wellbeing:

When I open the text messages and see that someone is giving me advice, I feel happy, like having someone care about me.

(Participant with OUD, male, 41 years old, security guard)

Group-based interventions such as Matrix sessions and group education were also described as enjoyable and accessible. Participants valued opportunities to exchange experiences, learn from peers, and build social connections in a relaxed and supportive environment.

In group education, I got to talk and share. I also made new friends.

(Participant with OUD, female, 40 years old, temporary worker)

I feel that I’ve equipped myself with some knowledge to protect myself, so that I don’t go back to using meth again.

(Participant with OUD, male, 42 years old, delivery man)

Providers similarly appreciated the dynamic and interactive nature of group sessions.

Group counseling is best, as patients exchange useful information with each other.

(Clinic head, female, 51 years old)

Improving control over methamphetamine use also brought a sense of relief and happiness in participants’ families, further reinforcing the perceived value of intervention:

My husband has changed, and I’ve changed too. Now life is happier. After taking my methadone, I just go home and do everyday things—go to the market, cook meals, and take care of my child. I don’t go out and use anymore.

(Participant with OUD, female, 36 years old, unemployed)

Taken together, these findings indicate that the interventions were positively perceived not only because of their contents but also because they fostered social accountability and meaningful engagement with peers, providers and family members.

Restrictive policy environment despite local demand for intervention

The need for addressing non-opioid substance use problems at methadone clinics was well recognized by local leadership. However, existing policies made it difficult to integrate such interventions into routine methadone services.

Providers unanimously described the increasing methamphetamine use among methadone patients and highlighted the urgency of addressing the problem:

I estimate that out of more than 600 patients here, around 200 are using methamphetamine. I think intervention is very much needed. When patients use it, they are often not clear-headed, which can create risks for both clinic staff and the patients themselves.

(Counselor, female, 35 years old)

Some clinic leaders emphasized that methadone clinics should take responsibility for addressing substance use beyond opioids:

Substance use disorders are not only about opioids. Interventions will need to cover other drug use, with treatment being provided in the clinics.

(Clinic head/District health center director, female, 53 years old)

Despite this recognition, structural barriers within the policy environment constrained integration efforts. Under the current legal framework, patients who test positive for non-opioid drugs during the methadone maintenance phase face termination of methadone treatment and possible incarceration (National Assembly of Vietnam 2025). This policy generated fear among some participants and discouraged participation in study activities:

Some patients were afraid to participate in eligibility screening because if their information was exposed, they might be caught and taken away.

(Clinic head, male, 42 years old)

Another constraint stemmed from the limited mandate of methadone clinics. Established in the 2000s to cope with the twin HIV – injection opioid use pandemic, this mandate authorizes methadone clinics to treat OUD only. At present, without formal policy approval, it might not be feasible to incorporate methamphetamine interventions in existing methadone programs:

Screening for or intervening on methamphetamine use is not considered part of methadone clinics’ responsibilities. Clear top-down guidance – a formal directive or policy – is needed to authorize such changes.

(Clinic head, male, 42 years old)

These findings highlighted a mismatch between local recognition of the need for methamphetamine interventions within methadone programs and the current policy framework governing methadone services, which limited their ability to respond to emerging substance use issues.

Workforce precarity and resource constraints

An overburdened workforce and limited financial resources constituted structural barriers that could hinder the delivery of methamphetamine interventions beyond the study context. Workforce challenges within Vietnam’s methadone programs had long been recognized, making the addition of new interventions particularly challenging (Trang, Anh, et al. 2025).

Methadone clinics were characterized by heavy workload and inadequate compensation and recognition for staff. Given the daily dosing requirement, methadone clinics were open every day, thus, staff had much fewer days off, compared to colleagues working in other services within district health centers. In about half of the clinics, methadone staff also provided HIV and PrEP treatments, further contributing to overwork and fatigue. Although staff managed to “get things done,” some admitted that this often meant trading quality for quantity:

With just two counselors in a methadone program serving 400 to 500 patients, it’s just not possible to get everything done.

(Lab technician, female, 40 years old)

During the study, some clinic staff faced significant workload pressures, as the study interventions required considerable preparation and time:

I often spent a whole evening – going back and forth between the Matrix counselor and patient manuals, reading and rereading the same lesson.

(Counselor, female, 41 years old)

This work basically takes up the whole morning – inviting patients in, explaining to them, going over their results then encouraging them to do better next time. It’s very time-consuming.

(Lab technician, male, 30 years old)

Staff shortage also limited the feasibility of providing one-on-one counseling at scale, potentially reducing the impact of motivational interviewing:

Sometimes there are dozens of positive cases, and one person cannot counsel each of them.

(Pharmacist/Admin, female, 36 years old)

Regarding financial resources, providers raised concerns about the sustainability of contingency management due to the costs of frequent methamphetamine tests and patient incentives. Current financial arrangements for methadone services covered only the most basic treatment requirements:

Most clinics calculate treatment fees at the most basic level. It means only one heroin test per month for a stable patient.

(Clinic head/District health center director, female, 53 years old)

While some providers suggested non-cash rewards as a more feasible way to sustain contingency management after the study ended, the cost of methamphetamine tests remained a major challenge:

It’s difficult, but rewards don’t always have to be in cash. They could be small gifts or certificates of recognition for patients who do well.

(Counselor, male, 44 years old)

Overall, these findings highlighted that although providers recognized the value of methamphetamine interventions, workforce shortages and financial constraints posed significant challenges to sustaining them within routine methadone services.

Logistical implementation challenges

Several logistical challenges emerged during implementation, many of which were inherent to the design of the interventions themselves. These included difficulties in coordinating group sessions, the burden of frequent urine testing, attempts to manipulate testing due to the reward structure and limited engagement with SMS reminders.

Groupwork.

Attendance at group sessions was often constrained by participants’ work schedules and personal commitments. Participants with regular jobs, particularly those in services or delivery work, found it difficult to attend sessions scheduled at fixed times, making it challenging to identify time slots that suited everyone.

When one person can make time, another can’t. The delivery men sit there with their phones ringing nonstop, with orders coming in that they can’t deliver. In that state, they can’t sit and listen properly.

(Clinic head, male, 42 years old)

Because patients often arrived at different times, counselors had to repeat the content multiple times in a single day:

There were days when we had to run the morning group education sessions two or even three times.

(Counselor, female, 40 years old)

Urine drug testing.

Twice-weekly urine testing was perceived as burdensome by some participants, particularly after the contingency management phase ended. Several participants expressed frustration and at times directed their dissatisfaction toward laboratory staff when asked to provide samples:

When I handed that patient the cup, he threw it straight down on the floor. He said that he had to go to work, and we kept asking him to do urine tests repeatedly.

(Lab technician, female, 34 years old)

Frequent testing also placed additional pressure on clinic staff, with lab technicians reporting that they had to work through weekends during the 6-month implementation phase.

Falsified urine samples.

The escalating reward schedule in contingency management created incentives for some participants to manipulate urine test results to maintain their reward streak:

Some patients, after accumulating a lot of points over time, if on a certain day they know they’ll test positive…will do whatever they can to get through that test.

(Pharmacist/Admin, female, 36 years old)

SMS reminders.

Engagement with SMS messages was also inconsistent. Providers noted that traditional text messaging had become less popular compared to social media platforms, and some participants had irregular access to their phones:

Nowadays people use social media a lot, they don’t really pay attention to SMS. The message may come and they don’t even notice it.

(Lab technician, female, 34 years old)

I just skim them (laughs), because it’s my mom’s phone – sometimes I read them, sometimes I don’t.

(Participant with OUD, female, 32 years old, shop assistant)

This evidence suggested that while the interventions were generally acceptable, several practical and logistical factors needed to be considered to facilitate smoother implementation in routine clinical settings.

DISCUSSION

This study identified multilevel barriers and facilitators to integrating evidence-based methamphetamine interventions into methadone clinics in Vietnam, drawing on the perspectives of both participants with OUD and methadone providers from the STAR-OM trial. Overall, the interventions were perceived as clinically beneficial and acceptable by both patients and providers; however, their integration into routine methadone services remains constrained by structural, programmatic and logistical factors.

A major facilitator of integration was the perceived positive impact and relevance of the interventions. Participants described meaningful changes these interventions supported and the sense of hope they inspired, while providers observed improved patient outcomes. These findings are consistent with international evidence demonstrating the effectiveness of behavioral interventions for reducing methamphetamine use (AshaRani et al. 2020; Knight et al. 2019) and with improvements in urine drug test results observed among trial participants over time (Giang et al. 2026).

Both participants with OUD and providers perceived contingency management as the most impactful intervention. While the motivating effects of incentives have been widely documented (Hser et al. 2011; Stanger and Budney 2019), the role of social accountability created through repeated testing and interactions with clinic staff in enhancing the effectiveness of contingency management has received less attention. Our findings suggest that the impact of contingency management extends beyond financial incentives, which aligns with evidence showing that non-monetary or low-cost contingency management rewards can be as effective as monetary rewards (Hue et al. 2025).

Evidence also indicates that methamphetamine use can be self-reported with acceptable validity (Bharat et al. 2023). This suggests that frequent biological testing may not be necessary in all settings. However, our findings showed that when test results were linked to incentives, some participants attempted to manipulate positive results. This tension suggests that monitoring strategies should be tailored to the purpose of assessment. Self-report may be sufficient for supportive counseling and routine follow-up, whereas some biological verification might still be required to ensure fairness. Low-barrier monitoring strategies such as home-based saliva testing verified via telehealth (Khazanov et al. 2023) or less frequent testing could reduce the burden of clinic-based urine screening while maintaining sufficient accountability. This will address the concerns about the costs and feasibility to sustain contingency management outside a research context (Oluwoye et al. 2020). Thus, implementing contingency management to address methamphetamine use in methadone settings is feasible, provided that context-appropriate motivational rewards and streamlined monitoring procedures are identified.

Despite strong clinical support for integrating methamphetamine interventions into methadone programs, the broader policy environment emerged as the most prominent barrier to implementation. Under the current legal framework, patients who test positive for drugs may face termination from methadone treatment and imprisonment (Government of Vietnam 2024; Vietnam’s National Assembly 2025). Thus, fear of legal consequences may discourage patients’ willingness to disclose their methamphetamine use and engage in therapeutic activities. These regulations directly conflict with harm reduction principles that emphasize person-centered recovery (Denning 2004; Van Den Berg et al. 2007), and contemporary conceptualizations of substance use disorders as chronic, relapsing conditions that require continuous, evidence-based care (World Health Organization and United Nations Office on Drugs and Crime 2020).

International evidence has consistently demonstrated that punitive drug policies can have devastating effects to the public health system, increased HIV risk behaviors (Debeck et al. 2017), reduced treatment engagement (Bruzelius et al. 2024) and weakened access to resources and support (Cohen et al. 2022).

In addition, the current mandate of methadone clinics – historically designed to address opioid injection and HIV transmission – limits their formal role to treating OUD. This narrow focus fails to account for the evolving drug use landscape in Vietnam, where methamphetamine use has become increasingly prevalent among methadone patients (Giang, Li, et al. 2022). As a result, methadone clinics face structural constraints to respond effectively to patients’ complex and evolving treatment needs.

Workforce limitations represent another major barrier to sustaining methamphetamine interventions in routine practice. Methadone clinics have long been understaffed and overburdened, with limited opportunities for specialized training or professional recognition (Trang, Anh, et al. 2025). While workforce shortage has always been an issue in substance use treatment globally, several countries have taken initiatives in developing career pathways and recognition for professionals working in this field (Arya et al. 2020; Trang, Diep, et al. 2025). In resource-constrained settings like Vietnam, streamlining existing workflows may help mitigate these challenges. Rather than creating parallel systems, methamphetamine-related evidence-based content could be integrated into routine assessments and counseling sessions as part of methadone care. Similarly, methamphetamine intervention-related indicators could be incorporated into existing monitoring and evaluation systems instead of requiring separate reporting forms. Although this approach would not eliminate additional workload, it could reduce duplication, and make implementation more feasible under current staffing and capacity constraints.

Logistical challenges in intervention delivery also warrant consideration. Although group-based intervention formats might better align with workforce constraints, organizing group sessions posed challenges related to participants’ work schedules and competing responsibilities. These findings highlight an important tension between short-term logistical feasibility and longer-term structural sustainability. Addressing these challenges, such as offering flexible group times, may help reconcile this tension and optimize implementation.

Moreover, limited engagement with traditional SMS and the widespread preference for social media platforms highlighted the need to update technological approaches to better reach and engage participants, such as adopting communication app-based strategies for participants with smartphone access.

Beyond structural barriers, the social context of treatment might play an important role in facilitating intervention engagement. Family support has been shown to play a critical role in the recovery of people with OUD in Vietnam (Trang et al. 2019, 2020). The desire to regain their families’ trust and to take care of their families motivated patients to engage in methadone treatment and maintain progress (Trang et al. 2019). Families also provided essential material support, such as housing and food, during periods of greatest needs (Trang et al. 2020). These findings suggest that more systematic involvement of families in methamphetamine interventions might enhance engagement, retention and treatment outcomes in methadone settings.

The recent policy shifts in Vietnam’s drug legal framework that occurred shortly after data collection was completed (National Assembly of Vietnam 2025) may alter the provision of care at methadone clinics, potentially affecting the relevance of some identified barriers and facilitators. Nevertheless, the findings remain informative in highlighting core implementation factors, particularly the constraining legal environment, workforce pressures, perceived intervention benefits, and logistical considerations, which are likely to persist despite policy changes.

Future research should reassess these implementation factors under the updated legal framework and explore strategies to implement evidence-based methamphetamine interventions for methadone patients in this evolving context.

Limitations

The study findings should be considered in light of several limitations. First, this qualitative study was nested within an intervention trial, which may have introduced social desirability bias in participants with OUD and providers’ accounts of feasibility, acceptability and perceived intervention impact. Second, the analysis was based on post-intervention interviews with participants with OUD and providers who remained in the study. We were unable to interview those who withdrew from or moved out of the study; these individuals might have experienced different or greater barriers to intervention engagement. Third, the findings reflected implementation experiences in methadone clinics in Hanoi and HCMC, two largest urban areas in Vietnam, and may not be fully generalizable to clinics in rural and mountainous provinces where resources are more limited and service delivery models may differ (Nguyen et al. 2023). Fourth, the relevance of identified barriers and facilitators may also change over time, given recent and ongoing policy changes affecting methadone treatment and responses to concurrent nonopioid use among methadone patients. Finally, we did not collect information on gender identity and sexual orientation, which may shape participants’ engagement with methamphetamine interventions.

CONCLUSION

The study provided qualitative evidence on the multilevel barriers and facilitators to integrating evidence-based methamphetamine interventions in methadone clinics in Vietnam. Findings indicated that these interventions were perceived as helpful and clinically acceptable by both patients and providers. Their integration into routine practice was primarily constrained by structural and programmatic barriers, including restrictive legal frameworks and workforce strain. Advocating for a more harm reduction-oriented policy approach, streamlining evidence-based methamphetamine-related content and indicators into existing workflows are essential to better support patients in need. As Vietnam’s drug policy continues to evolve, these findings offer important insights to inform strategies for implementing evidence-based methamphetamine interventions within methadone treatment settings.

Highlights.

• Methamphetamine interventions in methadone clinics were widely perceived as effective;

• Social accountability and engagement promoted patient outcomes;

• Punitive policies and narrow mandate of methadone clinics limited integration;

• Workforce shortages and financial resources hindered scalability;

• Logistical challenges included group scheduling, testing burden and low SMS use.