RESUMO
BACKGROUND: Despite the key role that people who inject drugs (PWID) play in the hepatitis C virus (HCV) epidemic, HCV treatment rates among this population have been historically low. Integrated models of HCV and substance use care have the potential to overcome some barriers to access; however, the evidence base is uncertain. This systematic review assesses the impacts of integrated HCV and substance use services on engagement in HCV care among PWID. METHODS: We searched five databases up to December 2018 to identify original quantitative studies evaluating the impacts of co-location of HCV and substance use services on engagement in the HCV cascade of care among adult PWID. We conducted a narrative synthesis, categorizing models based on patient entry point (a: HCV facility, b: substance use disorder (SUD) facility, and c: other facilities), and levels of integrated services offered (a: HCV/substance use testing only, b: HCV/substance use treatment, and c: testing/treatment + other services). RESULTS: A total of 46 articles corresponding to 44 original studies were included. Almost all studies (n = 42) were conducted in high-income countries and only six studies in the Direct-Acting Antiviral (DAA) era. Twenty-six studies discussed the integration of services at SUD facilities, one at HCV facilities, and seventeen at other facilities. Analysis of included studies indicated that overall integrated care resulted in improved engagement in HCV care (e.g., testing, treatment uptake and cure). However, the quality of evidence was predominantly low to moderate. CONCLUSIONS: Available evidence suggests that integration of HCV and substance use services may improve engagement along the continuum of HCV care among PWID. Given limitations in data quality, and very few studies conducted in the DAA era and in low- and middle-income settings, further research is urgently needed to inform strategies to optimize HCV care access and outcomes among PWID globally.