Mobile Opioid Outreach and Treatment: A Randomized Experiment

Last registered on February 10, 2026
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Pre-Trial

Trial Information

General Information

Title
Mobile Opioid Outreach and Treatment: A Randomized Experiment
RCT ID
AEARCTR-0016660
Initial registration date
September 01, 2025

Initial registration date is when the trial was registered.

It corresponds to when the registration was submitted to the Registry to be reviewed for publication.

First published
February 10, 2026, 10:52 AM EST

First published corresponds to when the trial was first made public on the Registry after being reviewed.

Locations

Country
United States of America
Region
Pacific Northwest

Primary Investigator

Name
Ariel Zucker
Affiliation
UC Santa Cruz
Contact Primary Investigator

Other Primary Investigator(s)

Additional Trial Information

Status
Withdrawn
Start date
2026-03-01
End date
2029-01-31
Keywords
Health
Additional Keywords
JEL code(s)
Secondary IDs
Prior work
This trial does not extend or rely on any prior RCTs.
Abstract
Combating the overdose epidemic is a central challenge of US health care policy. The most effective treatment for opioid use disorder is medication assisted treatment (MAT), but barriers to access lead more than eighty percent of those in need of MAT not to utilize it. Providers are increasingly exploring the use of vans to provide mobile opioid outreach and MAT to communities where traditional brick-and-mortar provision is costly or otherwise challenging. However, there is no empirical evidence on the impacts of mobile opioid outreach and treatment (MOOT).

In light of this, Pierce County Human Services (PCHS) has committed to randomizing the locations of two funded MOOT vans scheduled to be deployed in 2026-27---and hopefully beyond---serving approximately 300 opioid users per year. This proposal aims to develop an evaluation infrastructure around this randomization to measure the impact of the vans on treatment access and patient outcomes. Our primary research questions are: how does access to the vans impact (a) the likelihood of seeking treatment following referral and (b) the rate of opioid overdose in communities where vans are deployed?
External Link(s)

Registration Citation

Citation
Zucker, Ariel. 2026. "Mobile Opioid Outreach and Treatment: A Randomized Experiment." AEA RCT Registry. February 10. https://doi.org/10.1257/rct.16660-1.0
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Experimental Details

Interventions

Intervention(s)
Pierce County’s Human Services department (PCHS) will address barriers to treatment by bringing opioid use disorder (OUD) treatment to more remote communities with two mobile medical vans equipped to provide MAT, telehealth, counselling, and related services. The mobile MAT programs will be staffed with peer support and outreach staff to engage and build rapport with people in the areas where the mobile MAT van will provide services. The vans will park in suitable locations, such as county fire stations or libraries, in areas with a high density of overdose related emergency calls but without existing brick-and-mortar MAT services. The program is fully funded through 2027, with the potential for extension.
Intervention Start Date
2026-03-01
Intervention End Date
2028-03-31

Primary Outcomes

Primary Outcomes (end points)
At the time of initial registration, the planned primary outcome is the number of overdose-related emergency calls made in geographical areas randomized to treatment vs. control.
Primary Outcomes (explanation)

Secondary Outcomes

Secondary Outcomes (end points)
Secondary Outcomes (explanation)

Experimental Design

Experimental Design
The experiment will involve two vans providing MOOT in six locations in 2026 and 2027. The location of the van parking locations will be randomized among suitable locations, with the randomization pairwise stratified according to baseline location characteristics.

There is potential to continue service provision in randomized locations beyond 2027 and/or expand to other locations conditional on funding availability and partner interest.
Experimental Design Details
Not available
Randomization Method
Randomization done in office by a computer (Stata).
Randomization Unit
parking location
Was the treatment clustered?
Yes

Experiment Characteristics

Sample size: planned number of clusters
12 geographical clusters (surrounding parking sites).
Sample size: planned number of observations
12 geographical clusters.
Sample size (or number of clusters) by treatment arms
6 treatment clusters and 6 control clusters.
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)
NA: part of the purpose of the randomized pilot is to generate data for power calculations
Supporting Documents and Materials
IRB

Institutional Review Boards (IRBs)

IRB Name
UC Santa Cruz Institutional Review Board
IRB Approval Date
2025-09-04
IRB Approval Number
HS-FY2026-52
Analysis Plan