Effect of Messaging on Pragmatic Outcomes Within an Integrated Healthcare System (EMPOWeR)
Effect of Messaging on Pragmatic Outcomes Within an Integrated Healthcare System: a Randomized Trial (EMPOWeR)
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:
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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:
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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.
Study Overview
Status
Conditions
Detailed Description
The Effect of Messaging on Pragmatic Outcomes Within an Integrated Healthcare System: A Randomized Trial (EMPOWeR) study is designed to learn whether vaccine reminder messages that highlight a patient's choice of COVID-19 vaccines can help increase vaccine uptake among adults who are at higher risk for serious illness from COVID-19. The study will take place within KPSC, a large integrated health care system in southern California, and will use routine health care messages and reminders for updated COVID-19 immunization .
COVID-19 vaccination rates have declined since 2022, including among older adults and people with medical conditions that increase their risk of severe disease. Concerns about vaccine side effects, trust, and vaccine technologies may influence whether people choose to get vaccinated. The EMPOWeR study will evaluate whether providing information about vaccine choices can encourage individuals at higher risk of severe COVID-19 to receive an updated COVID-19 vaccine.
Adults who are eligible for a COVID-19 vaccine and who meet the study eligibility criteria will be included in the study. Eligible participants include adults enrolled for care at KPSC who are either 65 years of age or adults aged 18 to 64 years with certain health conditions that place them at increased risk for severe COVID-19 illness. Participants will not be asked to attend study visits or complete surveys. The study will use immunization data already collected in electronic health records as part of routine care.
Participants will be randomly assigned to one of five groups. One group will receive a standard COVID-19 vaccine reminder message currently used in routine care. The other four groups will receive messages that provide information about available COVID-19 vaccine options: mRNA and protein-based COVID-19 vaccines. These messages may:
- Inform participants that they can choose between two different COVID-19 vaccine types.
- Explain differences between vaccine technologies.
- Include information that both vaccine options are supported by health care professionals.
- Provide information about vaccine side effects and vaccine choice.
All messages will be delivered to eligible participants in early October 2026 using the participant's usual communication preferred language (i.e., English or Spanish). Follow-up reminder messages will also be sent later in the vaccination season (in early December 2026).
The main goal of the study is to determine whether these different messages increase receipt of the updated 2026-2027 COVID-19 vaccine. Additional goals include type of COVID-19 vaccine received receipt of an influenza vaccine, receiving influenza and COVID-19 vaccines on the same day, and the time between the reminder message and COVID-19 vaccination.
The study is designed to reflect real-world clinical practice. Participants will continue to receive routine medical care, and all vaccines will be provided through standard care processes. Researchers will compare vaccination outcomes across the different message groups to determine which communication approach is most effective for increasing vaccination uptake among high-risk adults.
This study may help health care systems better understand how to communicate with patients about vaccine options and improve vaccination coverage among populations at increased risk for severe COVID-19 illness.
Study Type
Enrollment (Estimated)
Phase
- Not Applicable
Contacts and Locations
Study Contact
- Name: Annette Regan, PhD
- Phone Number: 626-760-2482
- Email: annette.k.regan@kp.org
Study Contact Backup
- Name: Zendi S Yha, BS
- Phone Number: 626-372-5637
- Email: zendi.s.yha@kp.org
Study Locations
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California
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Pasadena, California, United States, 91101
- Recruiting
- Kaiser Permanente Southern California, Department of Research & Evaluation
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Contact:
- Zendi S Yha, BS
- Phone Number: 626-372-5637
- Email: zendi.s.yha@kp.org
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Contact:
- Annette Regan, PhD, MPH
- Phone Number: 626-760-2482
- Email: annette.k.regan@kp.org
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Participation Criteria
Eligibility Criteria
Ages Eligible for Study
Accepts Healthy Volunteers
Genders Eligible for Study
Description
Inclusion Criteria:
- Aged ≥18 years;
- Active KPSC member;
- Continuous membership from 27 August 2025 to 28 September 2026;
- Members who are aged 65 years and older, or adults aged 18-64 years with at least one of the following health conditions that increases their risk for severe COVID-19 illness, including: a) asthma, b) cancer, c) ischemic stroke, d) intracerebral or subarachnoid hemorrhage, e) transient ischemic attack, f) chronic kidney disease, g) dialysis, h) bronchiectasis, i) chronic obstructive, pulmonary disease (COPD), j) pulmonary fibrosis, k) cystic fibrosis, l) pulmonary hypertension, m) cirrhosis, n) non-alcoholic fatty liver disease (NALD), o) alcoholic liver disease, p) autoimmune hepatitis, q) diabetes, r) heart failure, s) coronary artery disease, t) cardiomyopathy, u) HIV, v) obesity, w) essential hypertension, x) primary immunodeficiency and other underlying immunocompromising conditions, y) solid organ or blood stem cell transplant, z) tuberculosis;
- No documented receipt of updated 2026-27 COVID-19 vaccine as of 28 September 2026;
- Has valid email information.
Exclusion Criteria:
- Unable to receive or opted out of email communication.
- People with unknown or missing sex.
- People who cannot safely receive a COVID-19 vaccine, including those who had a severe allergic reaction to a previous COVID-19 vaccine or have a contraindication to COVID-19 vaccine or a vaccine ingredient, will not be included in the study.
- People with metastatic or terminal illness, advanced illness, receiving hospice or palliative care, or resident in skilled nursing facilities.
- People who are pregnant or currently breastfeeding.
Study Plan
How is the study designed?
Design Details
- Primary Purpose: Health Services Research
- Allocation: Randomized
- Interventional Model: Parallel Assignment
- Masking: Triple
Arms and Interventions
Participant Group / Arm |
Intervention / Treatment |
|---|---|
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No Intervention: Usual Care
Standard COVID-19 vaccination reminder message sent as part of usual care. |
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Experimental: A. Choice-framed
Intervention arm tests the effects of choice-framed communication to increase patient's awareness of their available choices of COVID-19 vaccines, compared with usual care. |
A message communicating available choices of COVID-19 vaccines. |
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Experimental: B. Choice + vaccine platform-framed
Intervention arm tests the effects of choice-framed communication to increase patients' awareness of their available choices of COVID-19 vaccines AND explain differences in vaccine composition and mechanisms of protection by vaccine type, compared with usual care. |
A message communicating available choices of COVID-19 vaccines and differences in vaccine composition and mechanisms of protection by vaccine type. |
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Experimental: C. Choice + HCP trust-framed
Intervention arm tests the effects of choice-framed communication to increase patients' awareness of their available choices of COVID-19 vaccines AND emphasizes the support of healthcare personnel (HCP) for both vaccine options, compared with usual care. |
A message communicating available choices of COVID-19 vaccines and emphasizes the support of healthcare personnel (HCP) for both vaccine options. |
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Experimental: D. Choice + reactogenicity-framed
Intervention arm tests the effects of choice-framed communication to increase patients' awareness of their available choices of COVID-19 vaccines AND information about expected side effects, compared with usual care. |
A message communicating available choices of COVID-19 vaccines and expected side effects of available vaccines. |
What is the study measuring?
Primary Outcome Measures
Outcome Measure |
Measure Description |
Time Frame |
|---|---|---|
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Proportion of participants with documented receipt of the updated 2026-27 COVID-19 vaccine
Time Frame: up to 4 months after intervention
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Kaiser Permanente Southern California's electronic health record tracks the type of vaccine, dose, and date each patient receives. Immunization data will be retrieved from participants' electronic health records to ascertain COVID-19 immunization status during the study period. |
up to 4 months after intervention
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Secondary Outcome Measures
Outcome Measure |
Measure Description |
Time Frame |
|---|---|---|
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Type of COVID-19 vaccine received
Time Frame: up to 4 months after intervention
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The brand of COVID-19 vaccines received will be retrieved from participants' electronic health records to ascertain the type of COVID-19 immunizations received during the study period. |
up to 4 months after intervention
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Receipt of the 2026-27 influenza vaccine
Time Frame: up to 4 months after intervention
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Influenza vaccines received will be retrieved from participants' electronic health records to ascertain influenza immunization status during the study period. |
up to 4 months after intervention
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Co-administration of COVID-19 vaccine and influenza vaccine
Time Frame: up to 4 months after intervention
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The date of influenza and COVID-19 vaccines received will be retrieved from participants' electronic health records and used to ascertain the number of participants who received an influenza and COVID-19 vaccine on the same day. |
up to 4 months after intervention
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Time to immunization (in days) with an updated 2026-27 COVID-19 vaccine
Time Frame: up to 4 months after intervention
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The date of COVID-19 immunization will be retrieved from the participants' electronic health records and used to determine the number of days between message transmission and vaccination. |
up to 4 months after intervention
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Collaborators and Investigators
Sponsor
Collaborators
Investigators
- Principal Investigator: Annette Regan, PhD, Kaiser Permanente
Study record dates
Study Major Dates
Study Start (Actual)
Primary Completion (Estimated)
Study Completion (Estimated)
Study Registration Dates
First Submitted
First Submitted That Met QC Criteria
First Posted (Actual)
Study Record Updates
Last Update Posted (Actual)
Last Update Submitted That Met QC Criteria
Last Verified
More Information
Terms related to this study
Keywords
Additional Relevant MeSH Terms
Other Study ID Numbers
- 14603
- IRB Number 14603 (Other Identifier: Kaiser Permanente Southern California IRB)
Plan for Individual participant data (IPD)
Plan to Share Individual Participant Data (IPD)?
IPD Plan Description
The individual-level data that will be analyzed for this study will not be publicly available due to privacy concerns. Individual requests to access the study data can be made to the study PI.
Drug and device information, study documents
Studies a U.S. FDA-regulated drug product
Studies a U.S. FDA-regulated device product
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