ABSTRACT
BACKGROUND: Supervised consumption sites (SCS) have been shown to reduce receptive syringe sharing among people who inject drugs (PWID) in the United States and elsewhere, which can prevent HIV and hepatitis C virus (HCV) transmission. PWID are at risk of disease transmission and may benefit from SCS, however legislation has yet to support their implementation. This study aims to determine the potential impact of SCS implementation on HIV and HCV incidence among PWID in three California counties. METHODS: A dynamic HIV and HCV joint transmission model among PWID (sexual and injecting transmission of HIV, injecting transmission of HCV) was calibrated to epidemiological data for three counties: San Francisco, Los Angeles, and San Diego. The model incorporated HIV and HCV disease stages and HIV and HCV treatment. Based on United States data, we assumed access to SCS reduced receptive syringe sharing by a relative risk of 0.17 (95 % CI: 0.04-1.03). This model examined scaling-up SCS coverage from 0 % to 20 % of the PWID population within the respective counties and assessed its impact on HIV and HCV incidence rates after 10 years. RESULTS: By increasing SCS from 0 % to 20 % coverage among PWID, 21.8 % (95 % CI: -1.2-32.9 %) of new HIV infections and 28.3 % (95 % CI: -2.0-34.5 %) of new HCV infections among PWID in San Francisco County, 17.7 % (95 % CI: -1.0-30.8 %) of new HIV infections and 29.8 % (95 % CI: -2.1-36.1 %) of new HCV infections in Los Angeles County, and 32.1 % (95 % CI: -2.8-41.5 %) of new HIV infections and 24.3 % (95 % CI: -1.6-29.0 %) of new HCV infections in San Diego County could be prevented over ten years. CONCLUSION: Our models suggest that SCS is an important intervention to enable HCV elimination and could help end the HIV epidemic among PWID in California. It could also have additional benefits such facilitating pathways into drug treatment programs and preventing fatal overdose.
ABSTRACT
The objective of this randomized controlled trial was to assess the effects of a 1-year behavioral contract intervention on immunosuppressant therapy (IST) adherence and healthcare utilizations and costs among adult renal transplant recipients (RTRs). The sample included adult RTRs who were at least 1 year posttransplant, taking tacrolimus or cyclosporine and served by a specialty pharmacy. Pharmacy refill records were used to measure adherence and monthly questionnaires were used to measure healthcare utilizations. Direct medical costs were estimated using the 2009 Medicare Expenditure Panel Survey. Adherence was analyzed using the GLM procedure and the MIXED procedure of SAS. Rate ratios and 95% confidence intervals were estimated to quantify the rate of utilizing healthcare services relative to treatment assignment. One hundred fifty RTRs were enrolled in the study. Intervention group RTRs (n = 76) had higher adherence than control group RTRs (n = 74) over the study period (p < 0.01). And 76.1% of the intervention group compared with 42.7% of the control group was not hospitalized during the 1-year study period (RR = 1.785; 95% CI: 1.314, 2.425), resulting in cost savings. Thus, evidence supports using behavioral contracts as an effective adherence intervention that may improve healthcare outcomes and lower costs.