We previously found high engagement in SU treatment services in the past year among women enrolled in the WIHS, ²² which exceeded national averages of 10 to 30% of lifetime SU treatment among US adults with current SU.^9,27 Despite high rates of concomitant tobacco use and heavy alcohol use, we found comparatively low tobacco and alcohol use treatment utilization. Compared to SU treatment among those using opioids, treatment utilization was lower among those using crack/cocaine, the predominant substance used. This may be due in part to the lack of evidence-based medications for stimulant use disorders, ²⁸ compared with medications for opioid use disorders. ⁸ However, our findings may underestimate stimulant use treatment, as the questionnaires did not assess for psychosocial interventions (eg counseling, contingency management) or pharmacological options (eg topiramate, bupropion + naltrexone) to treat stimulant use disorders. Additional research is urgently needed to expand evidence-based treatment options for stimulant use disorders.

In the WIHS cohort, most women living with HIV had seen their HIV provider in the past 6 months, regardless of SU treatment utilization; this frequent touchpoint with healthcare suggests opportunities for linkage to or integration with other healthcare services for women with HIV and SU. Integrating SU care into HIV prevention and treatment settings may increase access to SU treatment services, and prior studies have shown that integrated SU/HIV treatment services improve health outcomes.^{29 bibr30-21501319241285531bibr31-21501319241285531bibr32-21501319241285531-33} For women at risk for HIV, despite having similar social vulnerabilities as women living with HIV, we found that fewer had seen any healthcare provider compared with women with HIV. These findings support the need for a status neutral approach to the HIV care continuum, offering comprehensive HIV prevention or treatment (pre-exposure prophylaxis (PrEP) or antiretroviral therapy), quality health care, and wraparound services, regardless of their HIV test result. ³⁴ In an article by Myers et al, ³⁴ several actionable items are emphasized to move toward a status neutral approach to HIV care, including (1) increased identification of individuals at risk for HIV and eligible for PrEP, (2) increasing PrEP awareness, (3) consistent sexual history and substance use history taking by clinicians regardless of perceived risk, (4) promoting sex-positive HIV prevention messaging, (5) expanding the Ryan White care model to offer services to persons without HIV including PrEP, mental health, and substance use services, and (6) expanding public funding for culturally competent sexual health clinics that offer comprehensive HIV prevention and treatment services. Individuals living with HIV and at risk for HIV are not distinct populations, and comprehensive services, such as substance use care, should be accessible regardless of their HIV test result.

Mental health care engagement of nearly 40% in this cohort of women using substances was higher than estimates of 20 to 25% in prior studies of mental health care among people living with HIV.^35,36 Considering that psychosocial interventions through counseling is an important part of SU care, it is possible that some of the mental health services also offered SU care, even if individuals did not specifically report SU treatment. Unfortunately, the questionnaires only assessed outpatient detoxification, but not outpatient counseling, as part of SU treatment.

Harm reduction services are a critical part of HIV and substance use care to mitigate drug-related harms, but women are often neglected as target populations of harm reduction interventions and studies. ⁶ We observed high rates of utilization of syringe service programs among women who inject drugs, however, our ability to assess true utilization of harm reduction services was limited by low number of responses to these questions. Our low responses may be due to lack of awareness of or access to harm reduction services, misunderstanding of the questions, or stigma and fear of punitive measures related to use of such services. We found high prevalence of HCV exposure among women with current substance use, especially injection drug use, emphasizing the important role of syringe exchange programs in preventing HIV and HCV transmission. Despite this, syringe exchange programs remain illegal in 11 U.S. states as of 2021. ³⁷ Future substance use research should include the assessment of harm reduction interventions and their outcomes, beyond just abstinence as the primary outcome of substance use care. In the clinical setting, many low-barrier care models for people who use substances emphasize shared-decision making when establishing goals of treatment, rather than focusing only on treatment guidelines ³⁸ ; for example, goals to reduce substance use, opt for safer routes of use, or practice safer injection practices to reduce infection risk—are all acceptable goals. Including such outcomes in research is needed to assess harm reduction interventions, reduce stigma, and advocate for policy changes that support harm reduction.

We found high rates of polysubstance use with tobacco and alcohol among women with current SU. In our study, women with concurrent SU and heavy alcohol use who did not utilize SU treatment also did not receive alcohol use treatment, and a similar association was seen with tobacco use. Thus, women with polysubstance use with alcohol or tobacco may be a group to prioritize for integrated alcohol, tobacco, and drug treatment programs. Conversely, one study on dual alcohol and tobacco dependence found that participants were more motivated, confident, and active in changing their alcohol use relative to smoking, and initiating cessation of both behaviors simultaneously proved challenging for participants. ³⁹ This could be due to use of another substance perceived as lower risk, while attempting to abstain from another substance. One of the challenges in our current system is the lack of treatments for polysubstance use, and treatments tend to be siloed by type of substance use. Further implementation studies are needed to evaluate the feasibility, acceptability, and effectiveness of integrating tobacco, alcohol, and drug use treatment services into each other and into HIV care settings through novel care delivery models.

Women with HIV have unique preferences and health needs when considering treatment or harm reduction strategies for their SU. Siloing HIV, mental health, and SU care creates additional barriers to care and perpetuates stigma, and therefore interventions to integrate treatment services specifically for women may facilitate engagement in SU care. Implementation research including qualitative data to inform patient-centered approaches are needed when considering the design of such interventions for women with HIV.