Lottery Incentive Nudges to Increase Influenza Vaccinations

Not Applicable

Completed

Conditions: Influenza
Vaccination
Health Behavior
Health Promotion

Interventions: Behavioral: Reminder
Behavioral: Financial incentive
Behavioral: Lottery

Registration Number: NCT05012163

Lead Sponsor: National Bureau of Economic Research, Inc.

Brief Summary: 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: 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.

Recruitment & Eligibility

Status: COMPLETED

Sex: All

Target Recruitment: 57581

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

Study & Design

Study Type: INTERVENTIONAL

Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Reminder / Active Control (No Financial Incentive)	Reminder	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.
Pennsylvania (PA) Lottery Scratch-Off Financial Incentive	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
Certain Cash Payout Financial Incentive	Reminder	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.
Pennsylvania (PA) Lottery Scratch-Off Financial Incentive	Reminder	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
Pennsylvania (PA) Lottery Scratch-Off Financial Incentive	Lottery	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
Certain Cash Payout Financial Incentive	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.

Primary Outcome Measures

Name	Time	Method
Flu Vaccination at Appointment	3 days after patient is randomized	Received flu vaccination at relevant PCP or specialty appointment.

Secondary Outcome Measures

Name	Time	Method
Flu Complications	During the 2021-22 flu season (Up to 11 months, from the time the patient is randomized through July 31, 2022)	Diagnosed with flu-related complications
Flu Vaccination Within 7 Days	Within 7 days of when patient is randomized	Received flu vaccination
Flu Diagnosis	During the 2021-22 flu season (Up to 8 months, from the time the patient is randomized through April 30, 2022)	Received a "high confidence flu" diagnosis (with positive polymerase chain reaction \[PCR\]/antigen/molecular test) and/or "likely flu" diagnosis (as assessed via International Classification of Disease \[ICD\] codes or Tamiflu administration or positive PCR/antigen/molecular test) Note that "likely flu" is a superset of the "high confidence flu" diagnoses.