Personalized Nudging to Increase Influenza Vaccinations

NCT ID: NCT06566534

Last Updated: 2025-01-16

Study Results

Results pending

The study team has not published outcome measurements, participant flow, or safety data for this trial yet. Check back later for updates.

Basic Information

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Recruitment Status

COMPLETED

Clinical Phase

NA

Total Enrollment

77482 participants

Study Classification

INTERVENTIONAL

Study Start Date

2024-09-09

Study Completion Date

2024-12-31

Brief Summary

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The purpose of this study is to prospectively test whether personalized, message-based nudges can increase flu vaccination compared with nudges that are not personalized or no nudges.

Detailed Description

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On average, 8% of the US population gets sick from influenza each flu season. Since 2010, the annual disease burden of influenza in the U.S. has included 9-41 million illnesses, 140,000-710,000 hospitalizations, and 12,000-52,000 deaths. The Centers for Disease Control and Prevention (CDC) recommends flu vaccination to everyone aged 6 months and older, with rare exceptions; almost anyone can benefit from the vaccine, which can reduce illnesses, missed work, hospitalizations, and death.

Successful efforts to get patients vaccinated against influenza have included text message reminders timed to precede upcoming flu shot-eligible appointments by up to 3 days. For example, the Roybal-funded flu shot megastudy conducted with Penn Medicine and Geisinger patients assessed the effectiveness of numerous types of messages in increasing vaccination, relative to standard communications by the respective health systems; an average 2.1 percentage point absolute increase (or 5% relative increase) in flu shots occurred due to the messages. Similarly, follow-up analysis of the megastudy using machine learning revealed that interventions differed in relative effectiveness across groups of patients as a function of overlapping covariates (e.g., age, sex, insurance type, and comorbidities). This analysis found that nudges optimally targeted to subgroups who responded most strongly to those nudges in the megastudy would have resulted in up to three times the increases in vaccination observed when simply randomly assigning patients to messages.

The present study aims to prospectively test the efficacy of a patient-facing, message-based nudge via short message service (SMS) texts that is predicted by this retrospective machine learning algorithm to be most effective for them (Personalized Nudge) relative to Passive Control (no messages), Active Control (simple reminder message), and Best Nudge (best performing message from the 2020 megastudy). Patients will be randomized to one of these four arms.

Of the 19 original messages from the megastudy, 12 can be carried out at Geisinger in 2024; the other 7 are either no longer relevant (e.g., those that refer to an ongoing coronavirus pandemic) or cannot be carried out due to a technical limitation (e.g., Geisinger is unable to send pictures, so nudges with pictures are excluded). A treatment assignment tree based on the algorithm described above will be applied to this subset of nudges to generate rules for assigning patients to personalized messages based on observed covariates.

The last patients will be enrolled on December 28th for appointments scheduled on December 31st. At least 90,000 patients are expected to be enrolled.

Conditions

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Influenza, Human

Study Design

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Allocation Method

RANDOMIZED

Intervention Model

PARALLEL

Primary Study Purpose

PREVENTION

Blinding Strategy

NONE

Although patients will not be explicitly informed of which arm they were randomized to, they will be aware of the messages they receive. The care provider will be provided an information sheet describing the intervention, but they will not be explicitly told which patients are enrolled or their randomized arm assignment.

Study Groups

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Passive Control

Patients randomized to this arm will receive no special communications, beyond what Geisinger sends out as standard practice.

Group Type NO_INTERVENTION

No interventions assigned to this group

Active Control

Patients will receive a simple message encouraging them to get a flu shot at their appointment.

Group Type EXPERIMENTAL

Reminder

Intervention Type BEHAVIORAL

Flu shot messages via SMS

Best Nudge

Patients will receive the nudge found to be numerically most effective in the megastudy, including language that a flu vaccine is "reserved" for them at their upcoming appointment.

Group Type EXPERIMENTAL

Reminder

Intervention Type BEHAVIORAL

Flu shot messages via SMS

Personalized Nudge

Patients will receive the nudge predicted to be most effective for them on the basis of the machine learning-derived treatment assignment trees.

Group Type EXPERIMENTAL

Reminder

Intervention Type BEHAVIORAL

Flu shot messages via SMS

Interventions

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Reminder

Flu shot messages via SMS

Intervention Type BEHAVIORAL

Eligibility Criteria

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Inclusion Criteria

* Age 18+
* Has not received the 2024 flu vaccine according to the Geisinger electronic health record (EHR) prior to randomization
* Has a non-acute, flu-shot eligible, in-person Geisinger appointment scheduled with enough time to be randomized
* Has a Geisinger primary care provider

Exclusion Criteria

* Cannot be contacted by SMS (e.g., due to insufficient/missing contact information in the EHR or because they opted out)
* Appointment type or department not approved for outreach by Geisinger leadership at the time of outreach
* Has an allergy to flu vaccines according to any EHR allergy table known to the study team
* Has a health maintenance modifier indicating they are permanently discontinued from receiving a seasonal flu shot
* Shares a phone number with someone who has already been enrolled
Minimum Eligible Age

18 Years

Eligible Sex

ALL

Accepts Healthy Volunteers

No

Sponsors

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Massachusetts Institute of Technology

OTHER

Sponsor Role collaborator

University of Michigan

OTHER

Sponsor Role collaborator

Abdul Latif Jameel Poverty Action Lab

OTHER

Sponsor Role collaborator

Geisinger Clinic

OTHER

Sponsor Role lead

Responsible Party

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Christopher F Chabris, PhD

Professor

Responsibility Role PRINCIPAL_INVESTIGATOR

Principal Investigators

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Christopher F Chabris, PhD

Role: PRINCIPAL_INVESTIGATOR

Geisinger Clinic

Locations

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Geisinger Clinic

Danville, Pennsylvania, United States

Site Status

Countries

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United States

References

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Milkman KL, Patel MS, Gandhi L, Graci HN, Gromet DM, Ho H, Kay JS, Lee TW, Akinola M, Beshears J, Bogard JE, Buttenheim A, Chabris CF, Chapman GB, Choi JJ, Dai H, Fox CR, Goren A, Hilchey MD, Hmurovic J, John LK, Karlan D, Kim M, Laibson D, Lamberton C, Madrian BC, Meyer MN, Modanu M, Nam J, Rogers T, Rondina R, Saccardo S, Shermohammed M, Soman D, Sparks J, Warren C, Weber M, Berman R, Evans CN, Snider CK, Tsukayama E, Van den Bulte C, Volpp KG, Duckworth AL. A megastudy of text-based nudges encouraging patients to get vaccinated at an upcoming doctor's appointment. Proc Natl Acad Sci U S A. 2021 May 18;118(20):e2101165118. doi: 10.1073/pnas.2101165118.

Reference Type BACKGROUND
PMID: 33926993 (View on PubMed)

Patel MS, Milkman KL, Gandhi L, Graci HN, Gromet D, Ho H, Kay JS, Lee TW, Rothschild J, Akinola M, Beshears J, Bogard JE, Buttenheim A, Chabris C, Chapman GB, Choi JJ, Dai H, Fox CR, Goren A, Hilchey MD, Hmurovic J, John LK, Karlan D, Kim M, Laibson D, Lamberton C, Madrian BC, Meyer MN, Modanu M, Nam J, Rogers T, Rondina R, Saccardo S, Shermohammed M, Soman D, Sparks J, Warren C, Weber M, Berman R, Evans CN, Lee SH, Snider CK, Tsukayama E, Van den Bulte C, Volpp KG, Duckworth AL. A Randomized Trial of Behavioral Nudges Delivered Through Text Messages to Increase Influenza Vaccination Among Patients With an Upcoming Primary Care Visit. Am J Health Promot. 2023 Mar;37(3):324-332. doi: 10.1177/08901171221131021. Epub 2022 Oct 4.

Reference Type BACKGROUND
PMID: 36195982 (View on PubMed)

Provided Documents

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Document Type: Statistical Analysis Plan

View Document

Related Links

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https://www.cdc.gov/flu-burden/php/about/index.html?CDC_AAref_Val=https://www.cdc.gov/flu/about/burden/index.html

Centers for Disease Control and Prevention. (2020). Disease Burden of Influenza.

Other Identifiers

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2024-0561

Identifier Type: -

Identifier Source: org_study_id

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