Contingency Management in HIV Care for Both Stimulant Use & ART Adherence (CoMBo)

CoMBo Study: Contingency Management for Both HIV And Stimulant Use in Primary Care

Methamphetamine use and associated sequelae have been rising, and represent a major barrier to successful control of the HIV epidemic. Methamphetamine use is associated with poor adherence to antiretroviral therapy for HIV, and the investigators propose a trial of contingency management (providing incentives for behavioral change) targeting both reduced methamphetamine use and improved adherence to HIV medications. The investigators will utilize a real-time, point-of-care urine assay for both outcomes, aiming to evaluate feasibility, acceptability and preliminary effectiveness of HIV care-based contingency management. Hair levels will also be studied as a quantitative outcome for reduction in methamphetamine use.

Study Overview

• Status: Completed
• Conditions: Hiv; Stimulant Use (Diagnosis)
• Intervention / Treatment: Behavioral: Contingency management

Detailed Description

Methamphetamine (MA) use is increasing in the United States, along with a sharp rise in overdose deaths. MA use is particularly prevalent among people with HIV (PWH), which can contribute to non-adherence to antiretroviral therapy (ART) and progression to AIDS. Contingency management (CM) is an evidence-based intervention that has repeatedly demonstrated efficacy in stimulant use disorder treatment and has also proved efficacious in improving ART adherence for those in care. Since uptake of CM outside of formal drug treatment programs has been limited, incorporating CM into HIV primary care is an important opportunity to expand access to treatment for MA use disorder while also supporting ART adherence.

This study addresses two barriers that have each limited outward expansion of CM into HIV primary care: 1) feasibility challenges for CM in clinical practice settings; as CM is traditionally delivered 2-3x weekly, this study explores a de-intensified CM schedule (e.g., once weekly visits) in HIV primary care; and 2) CM for ART adherence has been previously limited by the inaccuracy of indirect or non-timely measures of adherence.

The study utilizes a novel point-of-care urine tenofovir assay to perform POC testing on the same urine specimen for both ART use and MA non-use, enabling a truly paired CM intervention that addresses the following aims: 1) a pilot RCT evaluating feasibility of de-intensified (once weekly) combined contingency management for reducing MA use and increasing ART adherence in HIV primary care, compared to conventional twice weekly CM; 2) in-depth interviews following RCT completion to qualitatively explore the acceptability of this intervention to participants and their primary care providers; and 3) given incomplete ability to detect cumulative MA use with only once weekly urine testing, the investigators will study the correlation between monthly MA hair levels with monthly Timeline Followback interviews to validate use of hair MA levels to be able to quantitatively detect reduced use (in addition to abstinence) as a future study outcome.

• Study Type: Interventional
• Enrollment (Actual): 37
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • California
    • San Francisco, California, United States, 94110
      • UCSF at San Francisco General Hospital

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Stimulant use disorder
• Living with HIV or risk for HIV
• Suboptimal ART adherence (treatment or prevention)

Exclusion Criteria:

• Unable to provide urine testing weekly

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Contingency management arm; Participants are offered once weekly contingency management in clinic to support reduced stimulant use and HIV medication adherence.	Behavioral: Contingency management; Once weekly contingency management visit involving 15 minutes+ of motivational interviewing and provision of incentives for stimulant-negative urine tests and/or tenofovir-positive urine tests.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Feasibility: proportion of CM visits attended	The investigators will report multiple process measures as feasibility outcomes, though primary outcome is the number and proportion of contingency management visits attended (of 12). It is expected that 50% of participants will attend at least 6 or more CM visits, which is defined as minimum engagement suggesting feasibility of this HIV primary care-based CM intervention.	Measured during intervention participation.
Acceptability: in-depth interviews with participants, staff	The investigators will conduct in-depth qualitative interviews to understand factors and circumstances that influence CM engagement among PWH with stimulant use disorder and suboptimal ART adherence. These findings will also help elucidate mechanisms contributing to stimulant use reduction and ART adherence when once weekly CM is delivered to PWH in a designated primary care setting.	Interviews performed within 6 months of intervention participation.

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Effectiveness (Urine)	The investigators will report proportion of urine tests negative for stimulants; proportion positive for tenofovir.	Measured during intervention participation.
Effectiveness (Hair)	The investigators will correlate within-person changes in cumulative stimulant hair levels with the days free of stimulant use performed pre- vs. post-intervention using mixed effects Poisson regression with random effects for individual.	Analyzed within 1 year following hair collection

Collaborators and Investigators

• Sponsor: University of California, San Francisco
• Investigators: Principal Investigator: Ayesha Appa, MD, University of California, San Francisco

Publications and helpful links

General Publications

• Steiner G, Baral S, Riley ED, Shoptaw S, Chamie G, Roberts K, Suchman L, Knight K, Gandhi M, Coffin P, Appa A. Harm Reduction Contingency Management for Stimulant Use Reduction and Antiretroviral Therapy Adherence in HIV Primary Care: Protocol for an Implementation Effectiveness Study. JMIR Res Protoc. 2025 Aug 18;14:e67292. doi: 10.2196/67292.

Study record dates

Study Major Dates

• Study Start (Actual): September 15, 2023
• Primary Completion (Actual): May 30, 2024
• Study Completion (Actual): October 1, 2025

Study Registration Dates

• First Submitted: August 19, 2024
• First Submitted That Met QC Criteria: August 19, 2024
• First Posted (Actual): August 21, 2024

Study Record Updates

• Last Update Posted (Estimated): October 14, 2025
• Last Update Submitted That Met QC Criteria: October 9, 2025
• Last Verified: October 1, 2025

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Blood-Borne Infections; Urogenital Diseases; Genital Diseases; Pathologic Processes; Immune System Diseases; Infections; RNA Virus Infections; Virus Diseases; Communicable Diseases; Sexually Transmitted Diseases, Viral; Sexually Transmitted Diseases; Lentivirus Infections; Retroviridae Infections; Immunologic Deficiency Syndromes; Slow Virus Diseases; HIV Infections; Pathological Conditions, Signs and Symptoms; Disease; Acquired Immunodeficiency Syndrome
• Other Study ID Numbers: 23-38747

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No