COVID-19 Booster Incentives

COVID-19 Booster Incentives in a County-Run Health System

The goal of this work is to understand whether small financial incentives and messaging can increase the take-up of COVID-19 boosters among patients empaneled at a county public health system. The motivation for this work is the relatively low take-up of COVID-19 boosters. In California, where our experiment is based, only 59% of the population has been boosted, with only 13% receiving the recommended bivalent booster (State of California, 2022).

Study Overview

• Status: Completed
• Conditions: Booster Message; Booster Message + Financial Incentive
• Intervention / Treatment: Behavioral: Messaging; Behavioral: Financial Incentive; Other: Placebo

• Study Type: Interventional
• Enrollment (Actual): 57893
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • California
    • Martinez, California, United States, 94553
      • Contra Costa Health Plan

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

1. Age: 18 and above
2. At least one COVID-19 vaccination (primary series or monovalent booster) but no vaccination dose within the past 2-months.
3. Active phone number or email

Exclusion Criteria:

1. Opt-out of health system messaging

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Health Services Research
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Single

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Message Only; Email or SMS Booster Vaccination Reminder	Behavioral: Messaging; Booster reminder message
Placebo Comparator: Control; No message or financial incentive	Other: Placebo; Treatment as usual; no additional message and no incentive.
Experimental: Message + Financial Incentive; Email or SMS Booster Vaccination Reminder + Offer of a financial incentive for getting boosted in the next 2 weeks.	Behavioral: Messaging; Booster reminder message; Behavioral: Financial Incentive; Financial Incentive for getting boosted within 2-weeks of the message

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Vaccine booster	Received a booster vaccination within 2-weeks of message.	2 weeks

Collaborators and Investigators

• Sponsor: University of Southern California
• Collaborators: J-PAL North America

Study record dates

Study Major Dates

• Study Start (Actual): December 8, 2022
• Primary Completion (Actual): December 23, 2022
• Study Completion (Actual): December 23, 2022

Study Registration Dates

• First Submitted: December 8, 2022
• First Submitted That Met QC Criteria: December 8, 2022
• First Posted (Actual): December 13, 2022

Study Record Updates

• Last Update Posted (Actual): August 14, 2023
• Last Update Submitted That Met QC Criteria: August 9, 2023
• Last Verified: August 1, 2023

More Information

Terms related to this study

• Other Study ID Numbers: UP-21-01097

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Sharing Access Criteria: Researchers can request de-identified data from Contra Costa Health Services.
• IPD Sharing Supporting Information Type: STUDY_PROTOCOL; SAP; ANALYTIC_CODE

Drug and device information, study documents

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