IMPORTANCE: Women who inject drugs disproportionately report experiencing violence, yet they are overlooked in interventions and policy responses.

OBJECTIVE: To quantify and contextualize experiences of violence among Australian women who inject drugs.

DESIGN, SETTING, AND PARTICIPANTS: This mixed-methods cohort study used data from SuperMIX, a longitudinal cohort of people who inject drugs. Self-reported survey data from January 1, 2008, to December 31, 2019, were linked with administrative health records (hospital, emergency department, ambulance, and mortality). Qualitative interviews with 10 women between October 1 and November 30, 2023, explored experiences of violence and service access. Women were recruited via convenience sampling carried out across Melbourne, Australia, in areas with known drug markets and needle and syringe programs. Statistical analysis was performed between May and August 2025.

MAIN OUTCOMES AND MEASURES: Experience of assault or violence.

RESULTS: A total of 431 women were included, with a median age at baseline of 29 years (IQR, 25-34 years). By 2019, combining self-report and administrative data, 353 women (82% [95% CI, 78%-86%]) had experienced at least 1 assault, and 164 (38% [95% CI, 36%-43%]) had experienced at least 1 sexual assault. In administrative data, 82 of the 431 women (19% [95% CI, 15%-23%]) had ever had an assault-related hospital admission, 101 (23% [95% CI, 19%-27%]) had an assault-related emergency department presentation, and 74 (17% [95% CI, 14%-21%]) had an assault-related ambulance attendance. A total of 304 women (71%) completed at least 1 annual follow-up survey (total, 1677 follow-up surveys), of whom 178 (59% [95% CI, 53%-64%]) reported an assault since their last interview. Among 409 follow-up surveys reporting assault, seeking health care was reported in approximately one-third (128 [31%]). Qualitative findings revealed barriers to seeking health care, including stigma, fear of child protection involvement, lack of trust in clinicians, and logistical challenges.

CONCLUSIONS AND RELEVANCE: In this mixed-methods cohort study of Australian women who inject drugs, violence against women was pervasive and severe, yet rates of seeking health care remained low likely due to intersecting structural and social barriers. Recognition of the burden of violence is a critical first step in ensuring tailored responses to violence that meet the needs of marginalized women.