Highlights
- A tailored implementation approach significantly increased fidelity of Systems Navigation and Psychosocial Counselling (SNaP) delivery at HIV testing sites in Viet Nam.
- Viral suppression rates were substantially higher in PWID receiving the tailored intervention, despite similar near-universal ART initiation in both groups.
- Systematic tracking of implementation strategy modifications enabled responsive adaptations to local barriers, improving real-world feasibility in low-resource settings.
- Integrated, flexible interventions addressing both HIV care and opioid use disorder are crucial in addressing elevated morbidity and mortality among PWID populations.
Background
People who inject drugs (PWID) experience disproportionately high HIV incidence, face significant challenges in engaging with HIV care, and have elevated morbidity and mortality related to HIV and substance use disorders. In Viet Nam, HIV prevalence among PWID remains a critical public health challenge due to barriers including stigma, resource limitations, and variability in service delivery across clinical sites. Government-led efforts traditionally employ uniform, one-size-fits-all implementation strategies to roll out evidence-based interventions (EBIs); however, such approaches often fail to accommodate heterogeneous local needs, adversely impacting fidelity and clinical outcomes.
Systems Navigation and Psychosocial Counselling (SNaP) is an evidence-based, integrated intervention designed to improve early linkage to antiretroviral therapy (ART) and medication for opioid use disorder (MOUD) among PWID with HIV. However, optimizing the scale-up of SNaP requires strategies that are sensitive to the diverse contexts of health facilities across provinces.
Key Content
Methodology and Trial Design
Go VF et al. (2025) conducted a hybrid type 3 implementation-effectiveness cluster-randomised trial across 42 HIV testing sites in ten Vietnamese provinces. Testing sites were randomized 1:1 to either a standard implementation approach (a fixed package of 15 strategies) or a tailored approach (standard package plus an additional menu of 10 strategies selectable based on site needs).
Participants included HIV navigators, psychosocial counsellors, site directors, other staff, and PWID living with HIV (aged ≥18 years, active injecting within 6 months, ART-naïve at enrollment). The tailored approach incorporated a rapid needs assessment pre-implementation and iterative modifications during trial conduct to address site-specific barriers. Primary outcomes were fidelity to SNaP delivery (score range 0–200) and ART initiation; secondary outcomes encompassed current ART and medication for opioid use disorder usage, and viral suppression rates.
Implementation Outcomes: Fidelity and Adaptations
Fidelity measurements revealed a markedly higher mean score in the tailored arm (151.4 ± 21.4) versus standard arm (114.1 ± 13.5), corresponding to an adjusted mean difference of 37.3 points (95% CI 26.5–48.1), underscoring superior adherence to intervention protocols when local tailoring was employed.
Complementary research by Powell BJ et al. (2024) highlighted the rigorous method used to track modifications in implementation strategies in the tailored arm. Systematic monthly documentation identified dropped, added, or adapted strategies in response to pandemic-related disruptions, recruitment challenges, staff turnover, and resource constraints. This dynamic process ensured continuous alignment of intervention delivery with frontline realities, thus optimizing implementation fidelity.
Effectiveness Outcomes: ART Initiation and Viral Suppression
Nearly all PWID participants initiating SNaP commenced ART with comparable rates in the tailored (99%) and standard groups (99%), with minimal adjusted risk difference (1.3 percentage points, 95% CI 0.7–1.9). This ceiling effect on ART initiation likely attenuated differences between arms.
However, viral suppression rates were significantly higher in the tailored approach group, with an adjusted prevalence difference of 15.8% (95% CI 5.0–26.5%), translating into meaningful clinical benefits in virologic control. No significant differences were observed for current ART use or medications for opioid use disorder.
Morbidity and Mortality Considerations
Among 685 PWID followed longitudinally, 9% (63 deaths) were recorded, spanning both arms, with 14 deaths occurring prior to baseline assessment. These mortality rates emphasize the substantial ongoing health risks in this population despite intervention efforts.
Contextualizing Findings Within Broader Research
The value of integrated, flexible interventions combining HIV care with substance use treatment is corroborated by HPTN 074 and related studies (Miller WC et al., 2018), which demonstrated feasibility and increased ART and medication-assisted treatment uptake among PWID across multiple countries including Viet Nam.
Baseline analyses underscore regional differences in substance use patterns and risk behaviors among PWID, reinforcing the need for tailored approaches to address specific epidemiological and social contexts (Go VF et al., 2018).
Moreover, mortality analyses from HPTN 074 confirm that HIV-related and other causes persist as drivers of death among PWID, with integrated interventions serving to reduce this risk (Bartels SM et al., 2023). These converging data underpin the critical importance of tailoring implementation to local needs to sustain engagement and viral suppression.
Expert Commentary
This trial robustly demonstrates that tailored implementation strategies augment fidelity of a complex intervention addressing HIV and opioid use disorder among PWID in low-resource settings. While ART initiation rates were uniformly high, enhanced viral suppression suggests that tailored delivery improves post-initiation adherence and retention or effectiveness of counselling support.
A major strength of this pragmatic trial lies in its hybrid design focusing on both implementation and clinical endpoints, thus ensuring translatability of findings. Rigorous tracking of strategy modifications provides pioneering evidence that dynamic responsiveness to evolving contextual challenges is feasible and beneficial, particularly amid disruptions such as the COVID-19 pandemic.
However, the modest difference in ART initiation and absence of effect on opioid treatment use may reflect systemic barriers beyond site-level customization, including policy-level and structural factors. Future research should elucidate mechanisms by which tailored implementation improves viral suppression, potentially via enhanced patient engagement and task-shifting.
Clinically, this work advocates for paradigm shifts in governmental and organizational scaling practices from rigid, uniform implementation plans toward adaptable, participatory approaches that incorporate local stakeholder input and iterative problem-solving.
Conclusion
Tailored implementation of integrated systems navigation and psychosocial counselling for PWID with HIV in Viet Nam significantly enhances delivery fidelity and substantially improves viral suppression outcomes compared to standard implementation. This pragmatic evidence supports adoption of needs-based, flexible rollout strategies in resource-challenged settings to optimize care cascades for marginalized populations.
Sustained efforts to address barriers at multiple levels—policy, organizational, and patient—are critical to fully leverage ART and medication-assisted treatment benefits. Scaling such tailored approaches globally could accelerate progress toward HIV epidemic control among PWID.
References
- Go VF, Giang LM, Phan HTT, et al. Scaling an intervention for the engagement of people with HIV who inject drugs into care in Viet Nam: an implementation-effectiveness, cluster-randomised trial. Lancet Glob Health. 2025;13(12):e2111-e2121. doi:10.1016/S2214-109X(25)00331-6. PMID: 41240949.
- Powell BJ, Bartels SM, Giang LM, et al. Tracking modifications to implementation strategies: a case study from SNaP – a hybrid type III randomized controlled trial to scale up integrated systems navigation and psychosocial counseling for PWID with HIV in Vietnam. BMC Med Res Methodol. 2024 Oct 26;24(1):249. doi:10.1186/s12874-024-02367-3. PMID: 39462341.
- Miller WC, Go VF, et al. A scalable, integrated intervention to engage people who inject drugs in HIV care and medication-assisted treatment (HPTN 074): a randomised, controlled phase 3 feasibility and efficacy study. Lancet. 2018 Sep 1;392(10149):747-759. doi:10.1016/S0140-6736(18)31487-9. PMID: 30191830.
- Bartels SM, et al. Causes and risk factors of death among people who inject drugs in Indonesia, Ukraine and Vietnam: findings from HPTN 074 randomized trial. BMC Infect Dis. 2023 May 11;23(1):319. doi:10.1186/s12879-023-08201-3. PMID: 37170118.
- Go VF, et al. Regional differences between people who inject drugs in an HIV prevention trial integrating treatment and prevention (HPTN 074): a baseline analysis. J Int AIDS Soc. 2018 Oct;21(10):e25195. doi:10.1002/jia2.25195. PMID: 30350406.