Harris School of Public Policy Studies
Published February 1, 2022 | Version v1
Journal article Open

A 680,000-person megastudy of nudges to encourage vaccination in pharmacies

Creators

  • 1. University of Pennsylvania
  • 2. Ascension Health
  • 3. University of Chicago
  • 4. Northwestern University
  • 5. University of California, Los Angeles
  • 6. Geisinger Health System
  • 7. Harvard University
  • 8. Carnegie Mellon University
  • 9. Dartmouth College

Description

Encouraging vaccination is a pressing policy problem. To assess whether text-based reminders can encourage pharmacy vaccination and what kinds of messages work best, we conducted a megastudy. We randomly assigned 689,693 Walmart pharmacy patients to receive one of 22 different text reminders using a variety of different behavioral science principles to nudge flu vaccination or to a business-as-usual control condition that received no messages. We found that the reminder texts that we tested increased pharmacy vaccination rates by an average of 2.0 percentage points, or 6.8%, over a 3-mo follow-up period. The most-effective messages reminded patients that a flu shot was waiting for them and delivered reminders on multiple days. The top-performing intervention included two texts delivered 3 d apart and communicated to patients that a vaccine was "waiting for you." Neither experts nor lay people anticipated that this would be the best-performing treatment, underscoring the value of simultaneously testing many different nudges in a highly powered megastudy.

Data availability

The experimental data analyzed in this paper were provided by Walmart. We cannot publicly post individual-level data on vaccinations that we receive from our pharmacy partner, but aggregated summary data are available on the Open Science Framework (https://osf.io/rn8tw/?view_only=546ed2d8473f4978b95948a52712a3c5) (36). Data containing individual-level health information are typically not made publicly available to protect patient privacy.

Files

milkman-et-al-2022-a-680-000-person-megastudy-of-nudges-to-encourage-vaccination-in-pharmacies.pdf

Files (2.4 MB)

Additional details

Identifiers

DOI
10.1073/pnas.2115126119
Other
oai:uchicago.tind.io:9653

Funding

Gates Foundation
Flu Lab
University of Pennsylvania
Penn Center for Precision Medicine Accelerator Fund
Robert Wood Johnson Foundation
Unknown funder
AKO Foundation
Unknown funder
John Alexander
Unknown funder
Mark J. Leder
Unknown funder
Warren G. Lichtenstein

UChicago Information

Division(s)
Booth School of Business, Harris School of Public Policy Studies
Department(s)
Behavioral Science, Marketing, Harris School of Public Policy Studies Research Publications