Lottery Incentive Nudges to Increase Influenza Vaccinations

NCT ID: NCT05012163

Last Updated: 2024-12-30

Study Results

Results available

Outcome measurements, participant flow, baseline characteristics, and adverse events have been published for this study.

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Basic Information

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Recruitment Status

COMPLETED

Clinical Phase

NA

Total Enrollment

57581 participants

Study Classification

INTERVENTIONAL

Study Start Date

2021-09-04

Study Completion Date

2022-12-31

Brief Summary

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In the current study, the study team will explore whether small incentives are effective at promoting flu vaccine uptake. The study is designed to compare the relative efficacy of incentives of equal perceived expected value (EV) or equal implementation costs, to assess whether people are more likely to get vaccinated in response to lotteries with very high payoffs than to small certain cash payout or slightly higher-probability, more moderate payoffs. In particular, given the potential appeal of official state lottery tickets, one study arm will receive a Pennsylvania scratch-off lottery ticket for getting a flu vaccine. A primary hypothesis is that lotteries will outperform simple reminders (encouraging respondents to get the flu shot at their upcoming appointment) and the standard of care, representing the ambient healthcare system and public health campaigns to increase vaccination.

Detailed Description

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During the 2021-22 flu season, the study team will contact Geisinger patients who have a primary care or specialist appointment scheduled during flu season and encourage them to get a flu shot.

Patients will be randomized into 4 to 9 study arms, depending on a sample size projection completed in August 2021. Arms will test the relative efficacy of a variety of small monetary incentives on flu shot uptake. Incentives may include (a) a $1 Pennsylvania scratch-off lottery ticket (with top prize of $5,000), (b) $1 in cash, (c) entry into a raffle for $5,000 absent upfront odds, (d) entry into a raffle for $5,000, with 1-in-5,000 odds of winning, (d) entry into a raffle for $50, with 1-in-50 odds of winning, and (e) entry into a raffle for $500, with 1-in-500 odds of winning. There will be one no-contact control arm and at least 1 reminder control arm (with additional control arms added given sufficient sample size and additional message versions to be tested).

Included in the study will be current Geisinger patients 18+ years of age with no contraindications for flu vaccine who have an appointment scheduled during the study period with a provider who can administer the vaccine. The primary study outcomes will be the rates of flu vaccination and flu diagnosis during the 2021-22 season by targeted patients.

Conditions

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Influenza Vaccination Health Promotion Health Behavior

Keywords

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Lottery Financial Incentives

Study Design

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Allocation Method

RANDOMIZED

Intervention Model

PARALLEL

Eligible patients will be randomly assigned to one of four arms:

* Pennsylvania Lottery Scratch-Off Financial Incentive
* Certain Cash Payout Financial Incentive
* Reminder / Active Control Arm (No Financial Incentive)
* No Treatment Control Arm
Primary Study Purpose

PREVENTION

Blinding Strategy

SINGLE

Caregivers
Providers who prescribe vaccination and diagnose conditions will not be randomized to study arms or informed of patient assignment. Although patients will not be explicitly informed of which arm they were randomized to, they will be aware of the messages they receive.

Study Groups

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Pennsylvania (PA) Lottery Scratch-Off Financial Incentive

Participants in this arm will receive a message stating that they will receive a PA lottery $1 scratch-off ticket if they get a flu shot at an upcoming appointment. The message will mention that they could win $5,000 (the top prize for the scratch-off game).

Note: $1 scratch-off products vary over time; at study implementation, an active game with top prize of $5,000 (or the next-highest top prize) will be selected and will define the prize in the raffle absent upfront odds

Group Type EXPERIMENTAL

Reminder

Intervention Type BEHAVIORAL

Letter, short message service (SMS) text, phone, and/or email

Financial incentive

Intervention Type BEHAVIORAL

Letter, SMS, phone, and/or email

Lottery

Intervention Type BEHAVIORAL

Letter, SMS, phone, and/or email

Certain Cash Payout Financial Incentive

Participants in this arm will receive a message stating that they will receive $1 in cash if they get a flu shot at an upcoming appointment.

Group Type EXPERIMENTAL

Reminder

Intervention Type BEHAVIORAL

Letter, short message service (SMS) text, phone, and/or email

Financial incentive

Intervention Type BEHAVIORAL

Letter, SMS, phone, and/or email

Reminder / Active Control (No Financial Incentive)

Participants in this arm will receive a message stating that they can get a flu shot at an upcoming appointment. These participants will not be offered a financial incentive for getting a flu shot.

Group Type EXPERIMENTAL

Reminder

Intervention Type BEHAVIORAL

Letter, short message service (SMS) text, phone, and/or email

No Treatment Control

No additional contact beyond standard Geisinger flu shot communications

Group Type NO_INTERVENTION

No interventions assigned to this group

Interventions

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Reminder

Letter, short message service (SMS) text, phone, and/or email

Intervention Type BEHAVIORAL

Financial incentive

Letter, SMS, phone, and/or email

Intervention Type BEHAVIORAL

Lottery

Letter, SMS, phone, and/or email

Intervention Type BEHAVIORAL

Eligibility Criteria

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Inclusion Criteria

* Aged 18+
* Pennsylvania mailing address listed
* Geisinger primary care provider (PCP) assigned
* Upcoming appointment with PCP or select specialist who stocks and can administer the vaccine during the study period

Exclusion Criteria

* Has opted out of receiving messages from Geisinger on all modalities being tested
Minimum Eligible Age

18 Years

Eligible Sex

ALL

Accepts Healthy Volunteers

No

Sponsors

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Geisinger Clinic

OTHER

Sponsor Role collaborator

Massachusetts Institute of Technology

OTHER

Sponsor Role collaborator

National Institute on Aging (NIA)

NIH

Sponsor Role collaborator

National Bureau of Economic Research, Inc.

OTHER

Sponsor Role lead

Responsible Party

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Responsibility Role SPONSOR

Principal Investigators

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Michelle N Meyer, PhD JD

Role: PRINCIPAL_INVESTIGATOR

Geisinger Clinic

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

Provided Documents

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Document Type: Study Protocol

View Document

Document Type: Statistical Analysis Plan

View Document

Other Identifiers

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P30AG034532

Identifier Type: NIH

Identifier Source: secondary_id

View Link

2021-0484

Identifier Type: -

Identifier Source: org_study_id