Influenza, HumanNCT06566534
Personalized Nudging to Increase Influenza Vaccinations
A study testing Reminder in people with Influenza, Human, run by Geisinger Clinic at 1 site in United States.
Trial summary
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. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Influenza, Human
- What is being tested?
- Reminder
- Type of treatment
- Vaccines, Lifestyle or therapy programme
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 77,482 participants
- Where
- 1 siteUnited States
- Study dates
- 9 Sep 2024to 31 Dec 2024
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- 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
Who cannot join
- 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
Trial locations and contacts
1 site in 1 country.
About this study
Official title: A Prospective Randomized Trial of Personalized Nudges to Increase Influenza Vaccinations
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.
Read the detailed description
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
- Influenza, Human
- Being tested
- Reminder
- Keywords
- vaccination, health promotion, health behavior, reminder systems, behavioral economics, behavioral risk assessment, machine learning, personalization, nudges
- Medical subject headings
- Influenza, Human, Health Behavior
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
ReminderBehavioural
Flu shot messages via SMS
| Study group | Role | What they receive |
|---|---|---|
| Passive Control | No intervention | Patients randomized to this arm will receive no special communications, beyond what Geisinger sends out as standard practice. |
| Active Control | Experimental | Patients will receive a simple message encouraging them to get a flu shot at their appointment. Receives: Behavioral: Reminder |
| Best Nudge | Experimental | 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. Receives: Behavioral: Reminder |
| Personalized Nudge | Experimental | Patients will receive the nudge predicted to be most effective for them on the basis of the machine learning-derived treatment assignment trees. Receives: Behavioral: Reminder |
What is being measured
The primary outcome is the main question the study is designed to answer.
Number of Patients With Flu Shot Receipt Between Enrollment Date and Target Appointment Date
Our field experiment will be conducted with Geisinger Health patients via SMS messages sent prior to their first flu shot-eligible appointment during the study period, referred to as the "target appointment." The key dependent variable is whether patients receive a flu shot at or before their target appointment (as recorded in their electronic health records).
If patients cancel or do not show up for their target appointment after they have been randomized to a treatment and then schedule a new appointment during the study period, their new flu-shot eligible appointment becomes the target appointment and the outcome window extends from three days prior to the original appointment through the date of the appointment.
Patients who miss their target appointment and do not reschedule within the study period will still be included in the analysis. Their outcome window is from three days prior to the original appointment through the date of the original canceled appointment.
Measured: Between the enrollment date and target appointment date (at least 4 days and up to 4 months)
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted22 Aug 2024
- Study start9 Sep 2024
- Primary completion31 Dec 2024
- Study completion31 Dec 2024
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (2)Papers the sponsor has linked to this study.
- Other trials for Influenza, HumanStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Enrolment
- 77,482 participants (actual)
Sponsor and investigators
- Lead sponsor
- Geisinger Clinic
- Sponsor type
- University, hospital or other
- Collaborators
- Massachusetts Institute of Technology, University of Michigan, Abdul Latif Jameel Poverty Action Lab
- Responsible party
- Principal investigator, Christopher F Chabris, PhD, Geisinger Clinic
- Investigators
- Christopher F Chabris, PhD, Principal investigator, Geisinger Clinic
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06566534
- Sponsor's protocol ID
- 2024-0561
- Status last verified
- Jan 2025
- First submitted
- 20 Aug 2024
- Last updated
- 16 Jan 2025
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Yes: Data with no personally identifiable information will be made available to other researchers on the Open Science Framework for transparency. This will include the essential data and code needed to replicate the analysis that yielded reported findings.
Publications
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.
PubMed 33926993Patel 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.
PubMed 36195982
Study at a glance
From the registry record, last updated by the sponsor on 16 Jan 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- A Prospective Randomized Trial of Personalized Nudges to Increase Influenza Vaccinations
- ClinicalTrials.gov ID
- NCT06566534
- Acronym / sponsor ID
- 2024-0561
- Conditions
- Influenza, Human
- Keywords
- vaccination, health promotion, health behavior, reminder systems, behavioral economics, behavioral risk assessment, machine learning, personalization
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 77,482 participants (actual)
- Lead sponsor
- Geisinger ClinicUniversity, hospital or other
- Collaborators
- Massachusetts Institute of Technology, University of Michigan, Abdul Latif Jameel Poverty Action Lab
- Study start
- 9 Sep 2024 (actual)
- Primary completion
- 31 Dec 2024 (actual)
- Study completion
- 31 Dec 2024 (actual)
- First posted
- 22 Aug 2024 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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
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.
Study design
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 4
| Arm | Type | Receives |
|---|---|---|
| Passive Control | No intervention | –Patients randomized to this arm will receive no special communications, beyond what Geisinger sends out as standard practice. |
| Active Control | Experimental | Behavioral: ReminderPatients will receive a simple message encouraging them to get a flu shot at their appointment. |
| Best Nudge | Experimental | Behavioral: ReminderPatients 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. |
| Personalized Nudge | Experimental | Behavioral: ReminderPatients will receive the nudge predicted to be most effective for them on the basis of the machine learning-derived treatment assignment trees. |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (4 listed)
- 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
Key exclusion criteria (5 listed)
- 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
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| ReminderFlu shot messages via SMS | Behavioural | Active Control, Best Nudge, Personalized Nudge |
Primary outcome
Number of Patients With Flu Shot Receipt Between Enrollment Date and Target Appointment Date
Time frame: Between the enrollment date and target appointment date (at least 4 days and up to 4 months)
Our field experiment will be conducted with Geisinger Health patients via SMS messages sent prior to their first flu shot-eligible appointment during the study period, referred to as the "target appointment." The key dependent variable is whether patients receive a flu shot at or before their target appointment (as recorded in their electronic health records). If patients cancel or do not show up for their target appointment after they have been randomized to a treatment and then schedule a new appointment during the study period, their new flu-shot eligible appointment becomes the target appointment and the outcome window extends from three days prior to the original appointment through the date of the appointment. Patients who miss their target appointment and do not reschedule within the study period will still be included in the analysis. Their outcome window is from three days prior to the original appointment through the date of the original canceled appointment.
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 16 Jan 2025.
- Background: PubMed 33926993Milkman 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.
- Background: PubMed 36195982Patel 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.
- Individual participant dataSharing planned: Yes. Data with no personally identifiable information will be made available to other researchers on the Open Science Framework for transparency. This will include the essential data and code needed to replicate the analysis that yielded reported findings.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Christopher F Chabris, PhD principal investigator
Geisinger Clinic
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Reminder in people with Influenza, Human, run by Geisinger Clinic at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 4 inclusion and 5 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 16 Jan 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Number of Patients With Flu Shot Receipt Between Enrollment Date and Target Appointment Date (time frame: Between the enrollment date and target appointment date (at least 4 days and up to 4 months)). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT06566534, which also lists 2 linked publications.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 16 Jan 2025; AzTrials last refreshed its copy on 1 Nov 2026.