The RADAR cohort study of multilevel Influences on HIV and substance use

Northwestern University At Chicago, Evanston IL

Investigators

Linked publications, trials & patents

Abstract

We propose to continue the largest cohort study of young men in the Unites States with a very high HIV incidence. RADAR was launched in 2015 (renewed in 2020) to provide critical insights into risk and protective factors for HIV and drug use, and to identify facilitators and barriers to the implementation of effective strategies to end the epidemics of substance use and HIV among young men. RADAR is reflective of the US HIV epidemic; it focuses on the ages with the highest HIV and substance use disorder incidence, has exceptional representation of those most affected, and is located in the urban epicenter of the HIV and drug epidemics in the Midwest (i.e., Chicago/Cook County-4th highest incidence in US). We have been extremely productive in recruitment (N=1,357), retention (>80%), scientific outputs (113+ publications), and serving as a platform for additional innovative research (4 Fs, 4 Ks, 10 Rs, 50+ connected studies; 10 concepts via NIDA consortium). High-risk young men, such as those in our sample, account for 75% of all new HIV diagnoses among adolescents and young adults in the US and have not seen the declines found in other age groups. Substance use and multi-level health challenges (i.e., limited health knowledge or pre-existing psychological/biological factors) are key drivers HIV acquisition in this group. We propose a sophisticated multilevel research design, in which we will enhance the cohort with 600 new participants and continue to follow existing cohort members into their 30s and 40s. We will answer critical new questions about the substance use epidemics that drive the HIV epidemic and non-AIDS comorbidities. Aim 1: we will keep a pulse on emerging trends in drug use, HIV risk/preventive behaviors, and care continuum engagement. We will chart trajectories and multilevel risk/protective factors for substance use and HIV outcomes. Aim 2: RADAR will investigate the impact of health challenges, HIV, and substance use on key aging-related biological mechanisms and their impacts on vascular health and cognitive function comorbidities among young men living with and without HIV. Aim 3: we will engage in regular dialogue with key stakeholders, conduct implementation research, and disseminate findings directly to end-users to close research-to-practice gaps. Aim 4: RADAR will continue to add specimens and data to our large and well-characterized biobehavioral repository to provide a platform for high-impact science, and we will maintain existing collaborations. RADAR is a unique multilevel and longitudinal study of young men with a very high observed HIV incidence. The multi-cohort design (youth enrolled in 2008, 2011, 2015, 2020, now) provides a powerful design for examining trajectories and predictors while staying attuned to historical/generational differences–its continuation is critical to informing approaches to ending the substance us and HIV epidemics in all young men.