The goal of this clinical trial is to learn whether integrating routine, opt-out HIV and STI testing and pre-exposure prophylaxis (PrEP) navigation into primary care increases use of these services among adults ages 18 to 45 receiving care at Federally Qualified Health Centers in Mississippi. The main questions it aims to answer are:

1. Does the integrated model increase HIV and STI testing compared with standard care?
2. Does the integrated model increase PrEP navigation activity for eligible patients?
3. How do patients and clinic staff experience the integrated model in terms of satisfaction, comfort discussing sexual health, and feasibility in daily workflows?

Researchers will compare a standard-care period to a period when the integrated model is in place to see if the integrated model improves service use and patient experience.

Participants will:

1. Receive usual primary care, with HIV/STI testing and PrEP discussions offered as a routine, opt-out part of care during the integrated period
2. Be invited, if eligible, to complete a brief survey about their clinic experience
3. For staff, be invited to take part in a short survey or interview about clinic workflows and the integrated model

This is a quasi-experimental, mixed-methods implementation study designed to evaluate an integrated sexual and reproductive health (SRH) model that embeds routine, opt-out HIV and sexually transmitted infection (STI) testing and pre-exposure prophylaxis (PrEP) navigation into primary care workflows at two Federally Qualified Health Centers (FQHCs) in Canton and Yazoo City, Mississippi. The study focuses on adults ages 18-45 receiving primary care at participating clinics, a population experiencing high HIV/STI burden and structural barriers to SRH services, including limited routine testing, low PrEP uptake, and fragmented referral pathways. The intervention is informed by the Comprehensive Theory of Integration and aims to normalize HIV/STI testing as part of routine care while strengthening PrEP navigation and care coordination within existing clinic infrastructure.

The intervention operates at the clinic and workflow level rather than at the level of individual randomization. During the standard-care period, HIV/STI testing and PrEP discussions occur based on provider discretion or patient request, supported by existing electronic health record (EHR) prompts. During the integrated-care period, the study implements standing orders for nurses and peer navigators to initiate HIV tests, guideline-aligned STI tests, and PrEP navigation for eligible patients; EHR prompts and templates that cue providers to offer testing and PrEP in an opt-out manner; embedded peer navigation and daily team huddles to support linkage and follow-up; and training and technical assistance to promote culturally responsive, stigma-informed care. These changes are designed to be feasible within typical FQHC staffing and technology constraints.

The study uses a 24-month pre-post design, with a 12-month standard-care phase followed by a 12-month integrated-care phase. Primary quantitative data will be derived from de-identified or limited EHR extracts containing variables such as age, sex, race/ethnicity, visit type, HIV/STI test ordering and completion, PrEP offers and navigation steps, and documented declinations. Additional quantitative data will be collected through brief patient surveys assessing visit experience, satisfaction, comfort discussing sexual health, perceptions of opt-out testing, and experiences with PrEP discussions and navigation. Qualitative data will be obtained via semi-structured key-informant interviews and surveys with medical providers, nurses/medical assistants, patient navigators and community health workers, and clinic administrators, as well as interviews with a subset of patients, to explore implementation processes, barriers and facilitators, perceived impact, and sustainability.

No experimental drugs or devices are used, and all HIV/STI testing and PrEP services adhere to current clinical guidelines as part of routine care. The research procedures consist of (1) implementing and monitoring the integrated workflow; (2) abstracting EHR data under an IRB-approved waiver of consent and, where applicable, HIPAA authorization; and (3) collecting survey and interview data from patients and staff under informed consent. The primary implementation outcome is change in HIV/STI test uptake among adults ages 18-45 between the standard-care and integrated-care periods. Secondary outcomes include changes in PrEP navigation activity, patient-reported satisfaction and comfort discussing sexual health, provider adoption and fidelity to integrated SRH workflows, and feasibility and acceptability of the intervention from staff and patient perspectives. Analytic plans include pre-post comparisons of service uptake and navigation metrics, as well as thematic analysis of qualitative data to identify contextual factors (e.g., staffing, workflow, stigma, policy environment) that influence successful integration and scalability of the model in high-need FQHC settings.

Inclusion Criteria:

• Adults ages 18 to 45 years.
• Receiving primary care services at participating Federally Qualified Health Center (FQHC) clinics in Canton or Yazoo City, Mississippi.
• Able to understand and read English (for participation in surveys and interviews).
• For staff key informants: current clinical, administrative, or support role at a participating FQHC site with responsibilities related to primary care, HIV/STI services, or care coordination.

Exclusion Criteria:

• Younger than 18 years or older than 45 years.
• Critically ill, psychiatrically unstable, or lacking capacity to provide informed consent for research participation.
• Unable to understand English for consent and survey/interview procedures.
• For staff key informants: unable or unwilling to provide informed consent for interviews or surveys.

De-identified individual participant data (IPD) that underlie the primary and secondary outcome results (selected EHR variables for adults ages 18-45 and de-identified patient and staff survey responses) will be shared. No direct identifiers or HIPAA-defined identifiers will be included, and small cells will be handled to reduce re-identification risk. IPD will be available within 12 months after publication of the main study findings and for at least 5 years thereafter. Data will be shared with qualified researchers who have a scientifically sound proposal, appropriate ethics/IRB approval, and a signed data use agreement with My Brother's Keeper, Inc. and partner clinics. Data will be provided via secure, encrypted transfer or a controlled-access repository.

De-identified IPD and supporting documents will be available beginning within 12 months after publication of the primary study results in a peer-reviewed journal or submission of the main results to ClinicalTrials.gov, whichever occurs first. Data will remain available for at least 5 years after initial release, or longer if required by funder or institutional policies. Requests received after that period may be considered on a case-by-case basis depending on data retention and feasibility.

De-identified IPD will be shared with qualified researchers at academic, clinical, or public health institutions for analyses that are consistent with the original study aims (for example, secondary implementation, health services, or equity-focused analyses) or address clearly justified, related scientific questions. Requestors must submit a brief research proposal, analysis plan, and evidence of IRB/ethics approval or exemption. Requests will be reviewed by the Principal Investigator and designated study leadership at My Brother's Keeper, Inc. and collaborating institutions to assess scientific merit, feasibility, and consistency with participant privacy protections and data-use agreements. Approved requestors will sign a data-use agreement that prohibits any attempt at re-identification and limits data use to the approved project. Data will be provided via secure, encrypted transfer or a controlled-access data repository.