The methamphetamine use continuum and associated risk factors among cisgender men and transgender people with male sex partners

Abstract

The methamphetamine (meth) epidemic in the United States (US) disproportionately impacts cisgender men and transgender people who have sex with males (CMTSM). This confers a disparate burden of meth-related sequelae, including cardiovascular, cognitive, and psychiatric conditions. Among CMTSM, meth is syndemic with HIV, posing a threat to the US initiative of Ending the HIV Epidemic. Behavioral and pharmaceutical interventions for stimulant use disorder (StUD) with meth have been developed, yet none have been brought to scale. Moreover, while period and lifetime prevalences of meth use among CMTSM have been described, little is known about how often individual CMTSM initiate meth use and how their use of meth changes over time. Understanding these meth use patterns may directly inform novel meth interventions. We leveraged Community-Based Participatory Research principles and a sequential, mixed-methods research design to characterize meth use patterns among CMTSM. We partnered with two community-based organizations, Peer Seattle and Seattle’s LGBTQ Center, throughout the research. In our first study, we used a phenomenological approach to conduct a qualitative study of meth use patterns among CMTSM in the Seattle, WA, US Area. We analyzed qualitative data with team-based thematic analysis. In our second study, using qualitative findings and available validated instruments, we designed a cross-sectional instrument to identify meth use patterns among CMTSM. We used the Think Aloud cognitive interviewing method to refine this instrument. After surveying CMTSM from across the US with this instrument, we described (i) the proportion of CMTSM who initiated meth and, (ii) among those who initiated meth use, the proportion who developed StUD or meth-related adverse outcomes (MRAO). We then used time-to-event analyses to describe median (i) age at meth initiation and (ii) interval from meth initiation to the development of StUD/MRAO. We then used log regression models to identify demographic correlates of (i) initiating meth and (2) developing StUD/MRAO. In our third study, we used log regression models to identify health and socioeconomic correlates of (i) meth initiation and (ii) developing StUD/MRAO. We then used time-to-event analyses to describe the median intervals between onsets of each correlate and (i) meth initiation and (ii) first evidence of StUD/MRAO. We then examined whether the onset of correlates tended to precede, co-occur with, or follow both (i) meth initiation and (ii) the development of StUD/MRAO. In the first study, we conducted qualitative interviews with 49 CMTSM. We identified three themes: (1) CMTSM are introduced to meth in a variety of settings and contexts; (2) frequency, volumes, and meth administration routes vary widely over time; and (3) patterns of meth use are influenced by the desire to cope with changing life circumstances and associated stressors. In the second study, fifteen CMTSM participated in cognitive interviews, allowing us to iteratively refine the study instrument. Including the original instrument, we produced nine preliminary versions of the instrument over twelve study visits, before the tenth version was evaluated with three participants and used for data collection. From June-October 2024, 1,720 CMTSM participated in the cross-sectional data collection effort. Among them, 428 (25%) initiated meth. Meth initiation was less prevalent among CMTSM assigned female sex at birth than those assigned male sex at birth (aPR: 0.41 [95% CI: 0.20, 0.71]). Meth initiation was also negatively associated with educational attainment. Among those who initiated meth and provided sufficient data to determine StUD/MRAO status (n=403), 67% met >1 criterion of StUD/MRAO, and these criteria were first met a median of 6 years after meth initiation. We did not identify demographic correlates of StUD/MRAO. In the third study, meth initiation was associated with HIV seropositivity, history of sex exchange, and housing instability. On average, meth initiation preceded HIV diagnosis, occurred the same year as first episode of sex exchange, and followed first episode of housing instability. Among those who initiated meth, the development of StUD/MRAO was associated with HIV seropositivity and a composite social vulnerability variable, which accounted for inability to afford basic needs, housing instability or homelessness, and sex exchange. All correlates of StUD/MRAO, on average, preceded the development of StUD/MRAO. Our findings reflect that the meth epidemic among CMTSM is heterogenous, but that most CMTSM who initiate meth are likely to develop StUD/MRAO. We observed clear socioeconomic disparities in terms of both initiating meth and, among those who initiate, developing StUD/MRAO. The HIV epidemic among CMTSM shares these disparities, suggesting that the ongoing syndemic of HIV and meth in this population is driven by social inequities – namely wealth disparities and economic deprivation among the most vulnerable. Public health interventions meant to prevent HIV among CMTSM should include meth-specific considerations. In turn, novel interventions for meth use that specifically aim to prevent the development of StUD/MRAO may be explored, as many CMTSM take years to develop these outcomes after first initiating meth. Such interventions may be offered alongside conventional HIV prevention and care services. However, addressing root causes of the HIV and meth syndemic appears to require systemic interventions, including the implementation of social programs and policies that support economic equity among CMTSM populations.