The goal of this interrupted time series quasi-experimental design study is to implement universal opt- out HIV testing and linkage to HIV preventive care in 15-21 year old adolescents visiting the pediatric emergency department (ED). The main question[s] it aims to answer are:

1. What is the uptake, reach and effectiveness of universally offered, opt-out HIV screening across pediatric EDs after implementing an adapted version of a tablet-based screening process?

2. What is the successful linkage to comprehensive HIV pre-exposure prophylaxis (PrEP) care using a novel, digital health platform? Participants will

   1. Complete the previously developed and validated computerized sexual health screen (cSHS) containing questions regarding their personal sexual health history
   2. Have the opportunity to opt-out of clinician-ordered HIV testing
   3. Patients meeting CDC criteria for HIV PrEP will be given the opportunity to enroll in the digital health PrEP linkage platform and followed for 3 months after enrollment.

Using a previously developed tablet-based, broad scale gonorrhea and chlamydia screening process, the investigators will adapt, refine, and test this process with the aim of increasing universally offered, opt-out HIV screening in the pediatric ED through electronic integration of patient reported data for provision of clinical decision support for HIV screening and identification of PrEP candidacy. The investigators will then use mHealth to link patients to PrEP services. The goal of this study is to (1) adapt, refine, and test this previously implemented multi-center, ED-based, screening study with a goal of increasing universally offered, opt-out HIV screening among adolescents in the pediatric ED and (2) link at-risk adolescents to PrEP services and preventive care. This will be accomplished through a network of children's hospital EDs (Pediatric Emergency Care Applied Research Network or PECARN). This research will contribute to the evidence base for creating clinically effective and sustainable HIV screening programs that can be successfully implemented into the clinical workflow of the ED. It will also improve identification and linkage to PrEP care for at risk adolescents using mHealth strategies by first identifying adolescents and young adults (AYA) who are PrEP candidates based on their responses to a computerized sexual health screen (cSHS) and subsequently (1) providing clinical decision support to providers via the electronic health record and (2) direct text messaging from the cSHS to PrEP candidates providing educational content and connecting youth to a PrEP navigator. This intervention will rely on an innovative approach that electronically integrates patient-reported data to guide clinical decision support.

Inclusion Criteria:

• All patients 15-21 years of age visiting a pediatric emergency department.

Exclusion Criteria:

• Unable to understand English
• Critically ill
• Cognitively impaired
• Altered mental status