The goal of this behavioral interventional trial is to determine how best to communicate personalized cardiovascular risk information and support behavior change among participants enrolled in the Dallas Heart Study (DHS) cohort. The main questions it aims to answer are:

• What are the effects of presenting health information in a coarse vs. granular manner? (This question will be measured by randomizing participants to two groups: one group will get a cover letter with their health information communicated in a more detailed manner, while another group will receive a cover letter which presents their health information in a coarse manner. Two letters will be sent containing the same information regarding their results. 4 months after the second letter, participants will be asked about changes made for their health after receiving the letter)
• How curious are people about bettering their health after being presented their health information? (This question will be measured by placing QR codes linking educational health videos on each cover letter. Each letter will be sent twice with exactly the same health information but with new QR (Quick Response) codes. QR code use will be tracked by the study staff)

Researchers will assess whether participants who received different style letters had different responses to their health behaviors and medication afterward and will measure this with a follow-up phone call. Researchers will also assess the use of QR codes showing health-related videos (about physical activity, heart-healthy diet, diabetes medication, statin medication) by sending out two different letters with the same health information and format, but with different QR code-linked videos.

Participants will:

• Receive two letters in the mail, 4 weeks apart, containing their results from the Dallas Heart Study's 4th visit. The cover letter for this report will be randomized and will contain coarse vs. granular presentations of the participant's heart health risk.
• Receive a follow up call after 4 months to assess: whether they received the letter, whether they understood the information provided, whether they made any health changes after receiving the letter, whether they saw a healthcare provider after receiving the letter, whether the letter prompted a new diagnosis by a doctor, and whether the participant made any medication changes after the letter.

The Return of Cardiovascular Information Trial (RECITE) is a multi-factorial, adaptive randomized behavioral intervention trial which aims to determine how best to communicate personalized cardiovascular risk information and support behavior change among participants attending the Dallas Heart Study (DHS) fourth visit (DHS-4). This embedded behavioral intervention trial will evaluate two independent intervention components-risk information presentation and personalized action-planning support-to identify communication strategies that most effectively motivate and sustain healthy behavior change. The randomized intervention will be receipt of one of two different cover letter templates for the participant post-visit return-of-results letter.

Intervention Components:

The two primary treatment arms differ only in how one's health data measured during the DHS clinic visit are presented in the cover letter. Each cover letter shows the participant's AHA PREVENT (American Heart Association Predicting Risk of Cardiovascular Disease EVENTS) Risk Score results based on assessments performed at the DHS Visit. The risk score representation provides each participant's score compared to the distribution among DHS participants at Visit 3 (2020-2024). Each letter also provides the participant's actual estimated 10-year CVD (Cardiovascular Disease) risk based on the PREVENT Risk Score. To evaluate whether simplified (coarse) or detailed (fine) presentation of risk information better motivates behavior change, participants will be randomized to template cover letters presenting summary risk information as either:

• Arm 1, Coarse Risk Format: Participants receive the standard DHS-4 result report supplemented with visually intuitive risk indicators-such as color-coded categories (green = low risk, red = high risk) and representation of score in a histogram-for outcomes including heart attack, stroke, and diabetes.
• Arm 2, Fine Risk Format: Participants receive the same standard results report, but with precise numerical exact numerical percentile. (e.g., "Your risk of an adverse heart event is higher than 72 percent of DHS participants.") Instead of categorical color cues, there will be a line underlining the risk number that ranges from red "100" to green "0".

Each participant's result letter will be sent to them twice, initially approximately 8 weeks after their DHS Visit 4, and a second time 12 weeks after their visit. All participants will otherwise receive the same clinical test results and observational summaries, preceded by a cover letter, to ensure consistency with standard DHS return-of-results practices.

Each cover letter will also include text recommending that participants view a set of short, publicly available educational YouTube videos, published by reputable health sources such as the American Heart Association and Mayo Clinic, related to heart health and lifestyle behaviors. These recommendations will appear immediately above the video links. Each participant's cover letter, printed or emailed and irrespective of study arm, will have QR codes/short links to the educational videos as described below. The information will be identical for each participant, but the order in which these links are displayed in each cover letter will be randomized to reduce position bias/primacy effect. Each video link will be embedded as a unique URL (Uniform Resource Locator) tied to the participant's de-identified study ID (Identifier), which will allow the study to capture link clicks. Different QR codes/short-links will be provided in the cover letter to the first mailing (8 weeks after visit) and the second mailing (12 weeks after the visit).

Each video delivers practical, actionable guidance, such as:

• How to plan and structure daily routines to increase physical activity
• How to adopt and sustain healthy eating patterns
• Educational information regarding the following medication categories: diabetic medication, hypertension medication, and medication for high cholesterol.

Each participant will also get a follow-up phone call 16 weeks after their DHS study visit. The following questions will be asked:

• Did you get the full results report of your DHS visit? (Yes/No)

  1. If no, stop survey, ask participant "would you like us to resend it?" If yes, then we resend (after confirming preferred method/contact info)
  2. If yes, then continue with questions

• Did you understand the information provided to you? (Yes/No/I don't know/Refused)

• Did you make any health changes after receiving your results? (Yes/No/I don't know/Refused)

  1. If yes, what change did you make? (Exercise, diet, other (free text))

• Did the results report prompt a visit to your / healthcare provider? (Yes/No/I don't know/Refused)

• Did the results report prompt a new diagnosis of hypertension, diabetes, high cholesterol, or another condition by your healthcare provider? (Yes/No/I don't know/Refused)

  1. If yes, which? Check as many as apply: HTN (Hypertension), diabetes, high cholesterol, or other (free text)

• Were there any changes made to your medication as a result? (Yes/no/I don't know/refused)

Each subject will be identified solely by their pre-established and de-identified Dallas Heart Study (DHS) study ID, and no PHI (Protected Health Information) will be utilized for this clinical trial. Each unique, de-identified participant ID will be linked to a unique, de-identified QR code and short link created using GitHub Enterprise secure software and internal tools. We track participant engagement through website clicks using a simple web-based system (GitHub + Google Sheets) to record when a selection of publicly available educational YouTube videos is accessed. Each video link directs participants to a secure webpage hosted in a GitHub repository and served via GitHub Pages, a widely used academic and open-source static web hosting service. Specifically, GitHub maintains a repository of static (fixed and unedited) HTML (HyperText Markup Language) files, which are made publicly accessible on the internet as individual web links through GitHub Pages. Each file will correspond to each participant's de-identified study ID and video, each containing a small JavaScript component. This allows the links to be shared with participants either as QR codes or as URLs to directly type into a web browser. When a participant accesses a link, the system records minimal metadata (de-identified study ID, video identifier, and timestamp) and then immediately redirects the participant to the intended video content. Click metadata is transmitted securely and in real-time using encrypted HTTPS (HyperText Transfer Protocol Secure) connections to a Google-hosted secure web app (via Google Apps Script), which writes the de-identified information to a private Google Sheet accessible only to authorized study personnel. We systematically create HTML files and QR codes for each HTML web link using Python libraries and each participant's de-identified study ID only. No protected health information, HIPAA identifiers, IP (Internet Protocol) addresses, or device-level data are collected or stored as any part of this process. The use of this system is considered minimal risk, as it does not involve activity beyond standard web navigation and collects only limited, non-identifiable engagement data. Participants do not have access to the underlying code, data storage location, or logs, and cannot modify or view collected data. The system does not install software, use cookies, or track user behavior beyond the single link-click event.

Inclusion Criteria:

• Attendance of the Dallas Heart Study-4 clinical visit
• Participant confirms ability and willingness to utilize short links/QR codes during clinical visit

Exclusion Criteria:

• Did not attend the Dallas Heart Study-4 clinical visit
• Did not confirm ability and willingness to utilize short links/QR codes
• Participants for whom a PREVENT-CVD score cannot be calculated (those who did not complete a laboratory collection, and/or height/weight measurements [for BMI calculation]), and/or BP assessment, and/or did not complete the medical history questionnaire)