Evaluating the Effectiveness of a Mobile HIV Prevention App to Increase HIV and Sexually Transmitted Infections (STI) Testing and PrEP Initiation Among Rural Men Who Have Sex with Men

The goal of this clinical trial is to test the efficacy of a mobile app, Combine, to increase the uptake of HIV and STI testing and pre-exposure prophylaxis (PrEP) over 24 months and to assess the effects of different implementation strategies on intervention maintenance among GBMSM in rural southern United States. The main aims of the study are:

* To assess the relative effects of three treatment conditions on gains in engagement in HIV prevention compared to a modified standard of care control condition
* Measure and assess secondary factors affecting app implementation
* Refine implementation strategies and coordinate with potential funders Participants will download an HIV prevention smartphone app and be randomly assigned to one of four groups:
* Control: App access only
* Self-testing: App access + ability to order HIV and STI self-test kits
* Motivational interview: App access + motivational interview to develop plans to use app effectively.
* Self-testing + motivational interview: App access + ability to order HIV and STI self-test kits + motivational interview to develop plans to use app effectively.

Researchers will compare each of the latter three groups to the control condition to see if HIV and STI testing increase in these groups

The uptake of HIV and STI testing among gay and bisexual men who have sex with men (GBMSM) in the rural southern US is low. However, HIV and STI testing is a fundamental gateway to preventive services, such as PrEP, and treatment provision. Thus, the research team must identify methods to increase the uptake of HIV and STI testing among this population that experiences disproportionate HIV and STI incidence. The research team has developed an app, Combine, that is an adaptation of HealthMindr, an app that has demonstrated efficacy in increasing the uptake of HIV testing among urban GBMSM. Combine was adapted using input from GBMSM in rural areas to address issues specific to this population such as increased experiences of stigma and reduced access to culturally competent care. The investigator proposes to conduct a Type 2 Hybrid Effectiveness-Implementation randomized controlled trial to test the efficacy of Combine to increase uptake of HIV and STI testing over 24 months of follow-up and to examine the effect of different implementation strategies among GBMSM in the rural South. Combine will include components for self-administered risk assessments, developing and supporting a plan for frequent HIV and STI testing, information about PrEP, and PrEP and HIV/STI testing provider locators. Previous trials of app-based HIV prevention have included the ability to order free HIV and STI self-test kits. However, there is no consensus among health officials around whether at-home self-tests are an optimal solution for increasing HIV and STI testing. Additionally, despite the availability of free HIV and STI self-test kits in previous studies, large proportions of men still do not complete HIV tests, and even fewer complete STI tests. Thus, the investigator will evaluate the effect of two different intervention components on HIV and STI uptake in a 2x2 factorial trial design: availability of HIV and STI self-test kits ordered through the app and a motivational interview designed to enhance the existing app content, increased self-efficacy to develop and follow through with a testing plan, and develop strategies to deal with experiences of stigma.

The investigator will assess the main effects of the availability of HIV and STI self-test kits and the motivational interview on HIV and STI testing uptake, PrEP initiation, and intervention maintenance over 24 months of follow-up. The investigator's community-based partner, Engaging Arkansas Communities, will work with the research team through all stages of the project to ensure that the team is obtaining the necessary data to inform future implementation.

Eligibility Criteria:
Inclusion criteria

* Assigned male at birth and currently identifies as male
* Age 18-45 years, inclusive
* Reside in the U.S. South as defined by the Census Bureau or in Missouri
* Reside in a county classified as rural using the Index of Relative Rurality
* Have an Android or iPhone operating system (iOS) phone with active service
* Willing to download a study app to their phone
* English speaker
* Report anal sex with a man in the past 12 months
* HIV-negative or unknown serostatus
* Not currently using PrEP

Exclusion criteria

- Unable to provide consent