Efficacy of Communication Modalities for Promoting Flu Shots

Study Overview
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Brief Summary
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The purpose of this study is to test which modalities (mailed letter, short message service [SMS] text, or patient portal messages) are most effective for encouraging flu shots in high-risk patients.

Detailed Description
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The Centers for Disease Control (CDC) recommends a flu vaccination to everyone aged 6+ months, with rare exception; almost anyone can benefit from the vaccine, which can reduce illnesses, missed work, hospitalizations, and death. Flu shots are particularly important for patients at high risk of experiencing severe outcomes. During the 2020-21 and 2021-22 flu seasons, the study team sent messages to Geisinger patients in the top 10% of risk for flu and complications according to an artificial intelligence algorithm. Messages that told patients they were at high risk significantly increased their likelihood of getting vaccinated. The present study will extend previous work by testing which modality or modalities are most effective at boosting flu shot rates in patients at high risk. In previous campaigns, patients received messages via all communication modalities patients were eligible for (mailed letter, SMS text, and/or patient portal message). In this study, patients will be randomized to receive high-risk messages in one or more modalities.

Official Title
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Assessing the Relative Efficacy of Communication Modalities for Messages Promoting Flu Shots

Conditions
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Influenza Vaccination, Health Promotion, Health Behavior, Risk Reduction

Intervention / Treatment
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* Behavioral: Letter
* Behavioral: Patient portal
* Behavioral: SMS


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Included on a list of active Geisinger patients (all patients on this list attended at least one primary care appointment at Geisinger between 10/1/2008 and 4/13/2022, and either had a Geisinger primary care provider assigned as of April 2022, or were in the Electronic Health Record [EHR] since at least September 2021 and had at least one encounter in 2020-2022) Aged 18 or older In the top 10% of risk for flu and flu complications, according to Medial's flu complications machine learning algorithm (which operates on coded EHR data) Has a Geisinger PCP assigned as of August 2022 Has had an encounter in the last 2 years as of August 2022 Exclusion Criteria: - Cannot be contacted via any of the communication modalities (e.g., letter, patient portal, SMS) being used in the study, either due to insufficient/missing contact information in the EHR or because they opted out of all modalities

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Prevention
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| No Intervention: Control<br>No additional pro-vaccination intervention - some patients are currently targeted for flu vaccination messages due to a non-machine learning-based assessment that they are at high risk for complications, but are not told that they are at high risk or that they have been targeted | |
| Experimental: Letter only<br>This group will receive a letter telling them they are at high risk for flu and complications | Behavioral: Letter<br>* Mailed letter about flu vaccination<br>|
| Experimental: Patient portal only<br>This group will receive a patient portal message telling them they are at high risk for flu and complications | Behavioral: Patient portal<br>* Patient portal message about flu vaccination<br>|
| Experimental: SMS only<br>This group will receive an SMS telling them they are at high risk for flu and complications | Behavioral: SMS<br>* SMS about flu vaccination<br>|
| Experimental: Patient portal + SMS<br>This group will receive a patient portal message and an SMS telling them they are at high risk for flu and complications | Behavioral: Patient portal<br>* Patient portal message about flu vaccination<br>Behavioral: SMS<br>* SMS about flu vaccination<br>|
| Experimental: Letter + Patient portal + SMS<br>This group will receive a letter, a patient portal message, and an SMS telling them they are at high risk for flu and complications | Behavioral: Letter<br>* Mailed letter about flu vaccination<br>Behavioral: Patient portal<br>* Patient portal message about flu vaccination<br>Behavioral: SMS<br>* SMS about flu vaccination<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Flu vaccination | Flu vaccination within 4 weeks of the first message send date | 4 weeks after the first messages are sent in the study | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Flu Vaccine, Choice Architecture, Machine Learning, Perceived Credibility