A clinical trial funded by the National Institutes of Health found that delivering integrated HIV prevention and substance use disorder treatment through mobile medical units reduced all-cause deaths by 71% compared with participants who received peer navigation to community-based services alone, according to the official release. The findings come from the HIV Prevention Trials Network Study 094 (HPTN 094), conducted in five major U.S. cities and funded by NIH's National Institute on Drug Abuse (NIDA).
Key takeaways
- A National Institutes of Health-funded trial found that delivering HIV prevention and addiction treatment through mobile medical units reduced all-cause deaths by 71% compared with peer navigation to community-based services alone.
- The trial, HPTN 094, enrolled 409 adults who injected drugs, had opioid use disorder and were not on medication for opioid use disorder (MOUD) at enrollment, across five U.S. cities.
- There was no measured difference in PrEP or MOUD use between the two study groups, but 14% of participants were using MOUD at 26 and 52 weeks, up from zero at the start.
- Researchers say the mortality finding is significant but that replication is needed before the mobile-unit model is scaled up.
What the Trial Measured
The trial enrolled 409 adults without HIV who injected drugs, had opioid use disorder, were not taking medication for opioid use disorder (MOUD) at enrollment, and were willing to consider MOUD. Participants were split into two groups, each receiving 26 weeks of peer navigation. One group's peer navigation was paired with integrated preexposure prophylaxis (PrEP), MOUD, and limited clinical and supportive services delivered directly on a mobile medical unit. The other group received peer navigation that linked participants to existing non-mobile community services.
The study's primary comparisons looked at use of daily oral PrEP and MOUD between the two groups. Reduced mortality was tracked as a secondary outcome, and according to NIH, it was the result that turned out to be statistically significant, even though the primary measures of medication uptake showed no difference between arms.
NIH noted that while verified PrEP use was low in both groups at 26 weeks, it was favorable when compared with self-reported PrEP use documented elsewhere among people who inject drugs.
The Headline Figures
| Measure | Mobile Unit Group | Community-Based Group | Change |
|---|---|---|---|
| All-cause mortality | Lower | Higher (reference group) | 71% reduction |
| MOUD use at 26 and 52 weeks | 14% | Not stated as significantly different | No significant difference reported, but up from 0% at enrollment |
| Oral PrEP use at 26 weeks | Low | Low | No significant difference reported |
| Total participants enrolled | 409 (both groups combined) | Not stated | Not stated |
The 71% mortality reduction is the figure NIH is emphasizing in its release, framed as evidence that the mobile-unit delivery model itself, rather than any single medication, may be driving the survival benefit. The agency's release describes this as a secondary outcome, distinct from the primary endpoints of PrEP and MOUD uptake, which showed no measurable difference between the two study arms.
Which Outcomes Moved and Which Didn't
NIH's release draws a clear line between what changed and what didn't. PrEP and MOUD usage rates, the trial's primary outcomes, did not differ significantly between the mobile-unit group and the community-referral group. Yet 14% of participants were using MOUD at both the 26-week and 52-week marks, a figure NIH and the study's co-chairs describe as clinically meaningful given that none of the 409 participants were on MOUD when the trial began.
Study co-chair Nabila El-Bassel of Columbia University said people who inject drugs 'often face fragmented systems, unstable housing, stigma, and other barriers that make sustained care difficult,' and said the findings reinforce the need for care models that 'meet people where they are.' NIDA Director Nora D. Volkow said that although effective interventions already exist for this population, 'there are significant barriers to their accessibility and use,' and that the mobile-unit findings 'suggest that delivering low threshold services through mobile units could save lives.'
Researchers also pointed to the low uptake of oral PrEP, even under structured peer navigation, as evidence of persistent acceptance challenges among people who inject drugs. NIH's release states this points to the importance of evaluating long-acting PrEP formulations for this population going forward.
How the Trial Network Operates
HPTN 094 was conducted in Houston, Los Angeles, New York City, Philadelphia and Washington, D.C., and was funded by NIDA, the NIH institute that supports most of the world's research on the health aspects of drug use and addiction. The HIV Prevention Trials Network itself, which ran the study, is sponsored by NIH's National Institute of Allergy and Infectious Diseases. Overall support for the trial came through three NIH awards: UM1AI068619, UM1AI068617 and UM1AI068613.
Mobile medical units of the kind used in this trial function as traveling clinics that bring services such as HIV prevention medication, addiction treatment and supportive care directly into neighborhoods, rather than requiring patients to travel to a fixed clinic or hospital. One of the five units deployed for the study featured artwork designed by artist Shepard Fairey, according to NIH. This delivery model is intended to reduce the logistical and structural barriers, including unstable housing and stigma, that the study's co-chairs say keep people who inject drugs from accessing care consistently.
The trial's results were published in JAMA Psychiatry in 2026 under the title 'Mobile Units for Integrated Addiction and Prevention Services for People Who Inject Drugs: The HPTN 094 Randomized Clinical Trial,' with Steven Shoptaw of UCLA serving alongside El-Bassel as study co-chair.
What NIH Says Comes Next
NIH's release characterizes the mortality finding as significant but preliminary in terms of policy application, stating plainly that 'replication is needed' before mobile-unit models of integrated HIV and addiction care can be broadly recommended. The release does not specify a timeline for follow-up studies or name additional cities or funding for expansion.
The agency also did not state whether further analysis of the HPTN 094 data, such as a breakdown of causes of death or demographic subgroups most affected, will be released separately. For now, the findings stand as a single randomized trial result published alongside the NIH announcement.
Frequently asked questions
What exactly reduced deaths by 71% in this trial?
NIH attributes the reduction to the delivery model itself: 26 weeks of peer navigation combined with integrated PrEP, medication for opioid use disorder (MOUD), and limited clinical and supportive services delivered on a mobile medical unit, compared with peer navigation that simply referred participants to existing community-based services.
Did the mobile units get more people on PrEP or addiction medication?
No. NIH's release states there was no significant difference in PrEP or MOUD use between the two study groups. However, 14% of participants in the trial overall were using MOUD at 26 and 52 weeks, up from none at enrollment, which researchers called clinically meaningful.
Will mobile units like these be rolled out more widely?
NIH's release does not announce any expansion plans. It explicitly states that while the mobile-unit model 'may help overcome significant barriers' to HIV and addiction care, 'replication is needed' before broader conclusions can be drawn.