Numerous observational studies suggest that illicit drug users have inferior HIV treatment outcomes compared to other risk groups. Persons living with HIV/AIDS (PLWHA) and substance abuse have been reported to have delayed HIV diagnosis, poorer linkage and engagement in HIV care, greater difficulties with adherence, poorer virological responses, and reduced survival. Substance use may often be associated with other barriers to optimal care (e.g., mental illness, financial and legal difficulties, and inadequate housing and transportation). Clinic-based, individualized support delivered by case managers or patient navigators improves engagement in HIV care but requires substantial resources. Novel, evidence-based strategies are needed to identify substance-using at-risk persons, promote engagement in HIV care, enhance adherence, and improve treatment responses.

Mobile health (mHealth) technologies can collect real-time, patient-level data and facilitate responsive, interactive communication. Weekly text messages have improved adherence and viral suppression. mHealth holds promise for optimizing HIV care and adherence for drug users. Despite enthusiasm for these increasingly available and affordable tools, the evidence base to support implementation of mHealth in HIV care is limited, particularly among PLWHA and substance abuse. We invite original research and review articles that will stimulate efforts to understand the barriers and identify appropriate solutions for using mHealth to improve HIV care outcomes among marginalized, substance-using PLWHA. Potential topics include, but are not limited to:

• Quantitative and qualitative assessments of the need and acceptability of mHealth in HIV-infected substance users
• Ecological momentary assessment (EMA) studies of craving, use, or relapse to illicit drug use
• Theoretical frameworks for using mHealth for interventions to prevent nonadherence or drug use
• Methodological gaps and challenges in mHealth implementation
• Pilot studies and randomized trials of mHealth interventions for improving engagement, adherence, and treatment responses
• Use of technology to characterize geographic or neighborhood influences on HIV risk or treatment-related behavior

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