Healthcare for People Who Inject Drugs: Assessing Engagement and Unmet Need

Background: People who inject drugs (PWID) are an aging population with complex health needs. Multimorbidity is common and under addressed. Studies with PWID have shown that increases in the number of multimorbidity that were undiagnosed or undertreated, suggesting that care needs of this group are complex and impact healthcare utilization. Compounding this, PWID utilize healthcare at low rates, and care engagement is understudied. Lack of engagement in healthcare increases cost and worsens outcomes. However, no study to date has examined the impact of multimorbid chronic diseases on healthcare engagement for PWID and the holistic care needs of this population. Through an explanatory sequential mixed-methods study this research was designed to explore the healthcare needs of current and former PWID and how they engage in healthcare. Methods: Guided by the Behavioral Model for Vulnerable Populations (BMVP), this dissertation includes a systematic review of literature followed by an explanatory-sequential mixed methods study. The quantitative aim was a secondary analysis from the AIDS Linked Intravenous Experience (ALIVE) cohort, followed by qualitative interviews with ALIVE participants. Latent class analysis (LCA) was used to identify classes of multimorbid chronic diseases and explore the degree to which individual characteristics and level of substance use was associated with class membership. Data from LCA informed purposive recruitment for qualitative interviews from each class. Qualitative descriptive method was applied for thematic analysis using the Behavioral Model for Vulnerable Populations as a conceptual framework. Results: Dissertation findings include identification of complex healthcare needs for this population, the role of those needs on healthcare engagement, and can be applied to directions for future research, interventions, and policies. Healthcare need was characterized as three distinct classes of multimorbidity found with latent class analysis, each with its own implications for healthcare utilization and engagement. Findings from quantitative and qualitative analysis showed health insurance status did not serve as a barrier to healthcare access, with almost ubiquitous coverage in this post-ACA era study. While continuity of care was not associated with any class of multimorbidity, participant interviews highlighted that patient-provider relationship, strengthened by integrated care, were important for healthcare engagement. Additionally, a subset of participants described the benefits obtained from focused case management for wrap-around services, particularly those with co-occurring mental health disorder. Thematic analysis from this class also highlighted the importance of mental health stability as a means for management of substance use or recovery and other chronic diseases. Finally, quantitative and qualitative analysis showed prescription of MOUD linked with certain multimorbid classes, highlighting this as an important contributor to healthcare engagement. Conclusions: Multiple avenues for healthcare engagement, including positive patient-provider relationship, sustained health insurance, alignment of their healthcare needs with those designated by healthcare providers, and receiving integrated care to address pressing health needs among PWID. Policy considerations include the continued provision of low barrier access to publicly available insurance, passage of legislation that provides funding for clinics to provide wrap-around services to individuals with substance use disorder, and removal of MOUD prescription barriers impacting this at-risk population. Finally, this study affirms the importance of healthcare meeting the needs of this population at the level they are able to accept care. Holistic healthcare systems can address these needs best with integrated care systems that include harm reduction, are co-located with substance use and mental health treatment, and wrap around services, particularly as this population continues to age