Nudging Flu Vaccination by Making it Easy for Patients to Schedule a Flu Shot

The purpose of this study is to test whether messages that make it easy to schedule a flu shot appointment will increase flu shot rates in patients without an upcoming appointment. The study will also test which message versions and message timing are most effective for increasing flu vaccination.

Study Overview

• Status: Completed
• Conditions: Influenza
• Intervention / Treatment: Behavioral: Reminder

Detailed Description

The 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. Past work from the study team focused on encouraging flu shots for patients with upcoming appointments. However, many patients in the health system do not have any appointments during flu season.

Eligible patients without an upcoming appointment will be randomized to a passive control group (no message), an active control group (a basic message stating that the patient can get a flu shot at Geisinger) or one of several other messages informed by behavioral science ("ease", "waiting for you", "protect yourself - rare outcomes", or "protect yourself - frequent outcomes"). Patients will be randomly assigned to one of several message send dates. Messages sent via patient portal, short message service (SMS) text, email, and/or another modality, will include a link redirecting patients to a page where they can self-schedule a flu shot.

• Study Type: Interventional
• Enrollment (Actual): 139503
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • Pennsylvania
    • Danville, Pennsylvania, United States, 17822
      • Geisinger Clinic

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• Included in one or both of the following two base patient lists:

  1. Geisinger patient portal flu outreach list for Fall 2022
  2. A list of patients obtained from Geisinger's Phenomics and Clinical Data Core (PACDC). This list will include 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 as of October 2022
• Has had a Geisinger encounter in the last 2 years as of October 2022

• Either of the following, as of October 2022:

  1. Has a Geisinger PCP assigned in the Community Medicine, Pediatrics, or Internal Medicine service line
  2. In the last 2 years, has completed an appointment in a Geisinger specialty on a list of specialties approved by system leadership for flu shot communications
• Has not received a flu-shot during the 2022-23 flu season as of ~1 week prior to the message date (timeline may be slightly different, depending on data pull logistics), according to the Electronic Health Record (EHR)

• Does not have a scheduled in-person primary care or in-person flu-shot-eligible specialty appointment in the 12 weeks following their assigned message send date, as of ~1 week prior to the message date (timelines may be slightly different, depending on data pull logistics or clinical guidance)

  • As of this writing, the team plans to define a flu-shot-eligible specialty appointments as appointments in departments that have historically documented or administered flu vaccine. However, this approach may change slightly based on changing clinical guidance.

Exclusion Criteria:

• The CMSL/Marketing list will include patients in Geisinger's 65Forward or Community Care populations. If necessary due to logistical constraints, we may exclude these 65Forward and/or Community Care patients from our study.
• Cannot be contacted via the communication modality being used in the study (e.g., patient portal, SMS), e.g., due to insufficient/missing contact information in the EHR or because they opted out
• 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
• Is on a list of dismissed patients

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

6

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
No Intervention: Passive control; No message
Active Comparator: Active control message; A message that simply states that patients can get a flu shot at Geisinger	Behavioral: Reminder; Patient portal, SMS, email, and/or another modality
Experimental: Ease message; A message emphasizing the ease of scheduling a flu shot at Geisinger	Behavioral: Reminder; Patient portal, SMS, email, and/or another modality
Experimental: Waiting for you message; A message that states the patient's flu shot is "waiting" for them at Geisinger	Behavioral: Reminder; Patient portal, SMS, email, and/or another modality
Experimental: Protect yourself - rare message; A message that emphasizes the rare, dangerous outcomes of getting the flu (e.g., hospitalization, pneumonia), and states that a flu shot can offer protection from those outcomes	Behavioral: Reminder; Patient portal, SMS, email, and/or another modality
Experimental: Protect yourself - frequent message; A message that emphasizes the outcomes that frequently occur in people with the flu (e.g., fever, chills, missing important events), and states that a flu shot can offer protection from those outcomes	Behavioral: Reminder; Patient portal, SMS, email, and/or another modality

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Flu shot self-scheduling	Patient self-schedules a flu vaccine appointment through the patient portal (yes/no) This outcome measures whether the patient schedules an appointment within 4 weeks of the send date, but the appointment can occur more than 4 weeks past the send date.	Within 4 weeks of message send date

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Flu vaccination	Patient receives a flu vaccine (yes/no)	Within 4 weeks of message send date

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
High confidence flu diagnosis	Patient received a flu diagnosis via a positive PCR/antigen/molecular test (yes/no) during the 2022-23 flu season (from the patient's message send date through April 30, 2023).	Up to 7 months
"Likely flu" diagnosis	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) (yes/no) during the 2022-23 flu season (from the patient's message send date through April 30, 2023). Note that "likely flu" is a superset of the "high confidence flu" diagnoses.	Up to 7 months
Flu complications	Diagnosed with flu-related complications (yes/no) from the patient's message send date through July 31, 2023.	Up to 10 months
ER visits	Number of ER visits from the patient's message send date through July 31, 2023.	Up to 10 months
Hospitalizations	Number of hospitalizations from the patient's message send date through July 31, 2023.	Up to 10 months
COVID-19 vaccination rates	Received at least one COVID-19 vaccination (yes/no) during the 2022-23 flu season (from the patient's message send date through April 30, 2023).	Up to 7 months

Collaborators and Investigators

• Sponsor: Geisinger Clinic
• Collaborators: Massachusetts Institute of Technology; National Bureau of Economic Research, Inc.

Study record dates

Study Major Dates

• Study Start (Actual): November 8, 2022
• Primary Completion (Actual): January 3, 2023
• Study Completion (Actual): January 3, 2023

Study Registration Dates

• First Submitted: August 2, 2022
• First Submitted That Met QC Criteria: August 6, 2022
• First Posted (Actual): August 9, 2022

Study Record Updates

• Last Update Posted (Actual): January 5, 2023
• Last Update Submitted That Met QC Criteria: January 3, 2023
• Last Verified: January 1, 2023

More Information

Terms related to this study

• Keywords: Health promotion; Vaccination; Health behavior; Economics, Behavioral
• Other Study ID Numbers: 2022-0500

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: Yes
• IPD Plan Description: 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.
• IPD Sharing Time Frame: By the paper's online publication date. Data will remain available for as long as the Open Science Framework hosts it.
• IPD Sharing Access Criteria: The data on the Open Science Framework will be open to anyone requesting that information.
• IPD Sharing Supporting Information Type: Study Protocol; Statistical Analysis Plan (SAP); Analytic Code

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No