(P316-LB) Using a Secure Text-based Patient Messaging Platform to Recruit Community Clinic Patients for Participation in a Public Health Led Study on Mpox Vaccine Effectiveness.

Project: Los Angeles LGBT Center (Center) Health Information Services (HIS) assisted Los Angeles County DPH (DPH) in recruiting control subjects for a CDC led multi-jurisdictional case-control study on effectiveness of JYNNEOS Mpox vaccine. Cases were recruited from Mpox confirmed individuals reported to DPH; controls would be recruited from local STI and other clinics, with a 1:3 case-to-control ratio goal. HIS received a list of Center patients who received DPH funded STD-related services during a timeframe corresponding to DPH’s confirmed Mpox cases. HIS used CareMessage, an SMS-based platform, to send a secure Center-originated text message describing the study and including a hyperlink to a DPH web-based screening questionnaire. Interested patients could click on the hyperlink, which was unique to each patient, complete a screening questionnaire and if eligible, could complete the full survey.

Issue: 30,000 unique LGBT and other sexual minority individuals in the greater Los Angeles area choose to receive sexual and other health services from Center clinics. Public health objectives, such as partner notification for HIV and STIs, are most efficiently and effectively met when Center, rather than health department, employees contact patients. For this project the challenge was to find a method that would securely communicate study aims to potential controls, invite possible participation, and verify that they were the intended recipients, but not require respondents to enter personal identifying information.

Results: As of 3/24/2023, project outcomes were as follows. Of confirmed Mpox cases reported to DPH, 81 were eligible and enrolled in the study. HIS sent CareMessage survey invitations to 1,634 Center patients on December 16, 2022. A second reminder CareMessage survey invitation was sent on February 13, 2023 to original recipients who had not already responded. In total, 192 clients responded to the survey:

• 12% completed the screener but were ineligible,


• 79% were eligible and completed the questionnaire,


• 9% were eligible but haven’t completed the questionnaire,


• 88% of enrollment happened on the day each CareMessage went out and rapidly declined thereafter.

Lessons learned: Community health clinics can efficiently use secure SMS-based messaging platforms to collaborate with public health agencies on matters important to individual healthcare outcomes.