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Effect of Messaging on Pragmatic Outcomes Within an Integrated Healthcare System
Sponsor: Kaiser Permanente
Summary
COVID-19 vaccination among patients at high risk for severe disease has declined in the United States since 2022. Prior research, including discrete choice experiments (DCEs), has demonstrated that vaccine preferences are influenced by attributes such as effectiveness, safety, convenience, and protection against severe disease. Although DCEs provide valuable insights into stated vaccine preferences and decision-making, they rely on hypothetical scenarios and cannot directly assess how vaccine attributes influence real-world vaccine uptake. Additional research is needed to understand the relationship between vaccine characteristics and observed COVID-19 vaccination behavior in routine clinical practice. The EMPOWeR study is a pragmatic randomized controlled trial conducted within Kaiser Permanente Southern California (KPSC) to evaluate the effect of immunization messages and reminders that highlight COVID-19 vaccine choices on vaccine uptake. The primary research questions are: 1. Does having a choice in COVID-19 vaccine platform affect vaccine uptake among patients at high-risk of severe disease? 1a. Does having a choice in COVID-19 vaccine platform affect vaccine uptake among patients at high-risk of severe disease, when differences in vaccine platform are highlighted? 1b. Does having a choice in COVID-19 vaccine platform affect vaccine uptake among patients at high-risk of severe disease, when a trusted healthcare professional (HCP) endorses both vaccine options? 1c. Does having a choice in COVID-19 vaccine platform affect vaccine uptake among patients at high-risk of severe disease, when vaccine reactogenicity is highlighted? A secondary research question is: 2. Does having a choice in COVID-19 vaccine additionally increase uptake of influenza vaccine? During the 2026-2027 respiratory virus season, eligible KPSC members who are at high-risk of severe COVID-19 will be randomly assigned to receive a standard reminder message or a reminder message with additional information about available COVID-19 vaccine options.
Official title: Effect of Messaging on Pragmatic Outcomes Within an Integrated Healthcare System: a Randomized Trial (EMPOWeR)
Key Details
Gender
All
Age Range
18 Years - Any
Study Type
INTERVENTIONAL
Enrollment
1300000
Start Date
2026-09-28
Completion Date
2027-06-30
Last Updated
2026-09-29
Healthy Volunteers
Yes
Conditions
Interventions
Vaccine choice message
A message communicating available choices of COVID-19 vaccines.
Vaccine choice + platform-framed message
A message communicating available choices of COVID-19 vaccines and differences in vaccine composition and mechanisms of protection by vaccine type.
Vaccine choice + HCP trust-framed message
A message communicating available choices of COVID-19 vaccines and emphasizes the support of healthcare personnel (HCP) for both vaccine options.
Vaccine choice + reactogenicity-framed message
A message communicating available choices of COVID-19 vaccines and expected side effects of available vaccines.
Locations (1)
Kaiser Permanente Southern California, Department of Research & Evaluation
Pasadena, California, United States