Precision Vaccine Promotion in Underserved Populations

Previous studies have shown that low-cost, behavioral nudges through texting can increase influenza vaccination uptake compared to usual care. However, there are limited studies that evaluate the effect of decreasing barriers to scheduling, especially within safety net populations. The setting for this study, DHS, is the second largest public delivery system in the country and serves approximately half a million diverse patients that are eligible for vaccinations annually. This pilot study (one arm in a larger randomized controlled trial) will examine the effect of text messages highlighting MediCal health plan transportation resources (vs standard text messaging) on influenza vaccination rates in adults during the 2022-2023 flu season.

Study Overview

• Status: Completed
• Conditions: Influenza; Vaccine Hesitancy
• Intervention / Treatment: Behavioral: Text messaging

• Study Type: Interventional
• Enrollment (Actual): 228831
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • California
    • Los Angeles, California, United States, 90012
      • Los Angeles County Department of Health Services

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 6 months and older (Child, Adult, Older Adult)
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Los Angeles County Department of Health Services (LACDHS) primary care patients over 6 months of age

Exclusion Criteria:

• LACDHS patients less than 6 months of age

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Single

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: Standard Texts; Patients randomized to this study arm will receive a standard text reminding them about the importance of influenza vaccination. The standard texts will include a clinic call back number and patient portal self-scheduling for patients to schedule their influenza vaccines: #FirstName#, your flu shot is ready! Call your clinic at #ExternalRefNo# or visit the LA Health Portal at http://bit.ly/BookFluShot if you want this shot held for you.	Behavioral: Text messaging; Patients will receive up to 3 text messages reminding them about the importance of influenza vaccination during the 2022-2023 flu season.
Experimental: Standard Texts with Transportation messaging; Patients randomized to this study arm will receive standard texts plus transportation messaging including a phone number for patients to reserve transportation to a vaccination appointment based on MediCal health plan transportation resources: #FirstName#, your flu shot is ready! Call your clinic at #ExternalRefNo# or visit the LA Health Portal at http://bit.ly/BookFluShot if you want this shot held for you. You can call #Health Plan Phone Number# to schedule a free ride for your flu shot through #HealthPlanName#.	Behavioral: Text messaging; Patients will receive up to 3 text messages reminding them about the importance of influenza vaccination during the 2022-2023 flu season.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Number of Participants Vaccinated at the End of the Campaign Period	Number of Participants who received their influenza vaccination during the campaign period, as measured in the California Immunization Registry (CAIR2) to include vaccinations occurring both inside and outside the LADHS system. We assessed baseline vaccination status at the beginning of the flu season and excluded individuals who already received their vaccination.	6 months

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Heterogeneity of Treatment Effects for Demographics	Heterogeneity of treatment effects for demographic groups (previous vaccination status: vaccinated or unvaccinated)	6 months

Collaborators and Investigators

• Sponsor: University of Southern California
• Collaborators: University of California, Los Angeles; National Institute on Aging (NIA); Los Angeles County Department of Public Health
• Investigators: Principal Investigator: Daniella Meeker, PhD, University of Southern California

Study record dates

Study Major Dates

• Study Start (Actual): September 22, 2022
• Primary Completion (Actual): March 31, 2023
• Study Completion (Actual): June 1, 2023

Study Registration Dates

• First Submitted: September 9, 2022
• First Submitted That Met QC Criteria: September 9, 2022
• First Posted (Actual): September 13, 2022

Study Record Updates

• Last Update Posted (Actual): October 1, 2024
• Last Update Submitted That Met QC Criteria: September 25, 2024
• Last Verified: September 1, 2024

More Information

Terms related to this study

• Other Study ID Numbers: HS-22-00479; P30AG024968 (U.S. NIH Grant/Contract)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No