Testing Multiple Behavioral Science Strategies to Increase Flu-Shot Rates

University of Pennsylvania74,811 enrolled

Overview

This research aims to identify which behavioral science strategies are most effective at increasing flu vaccination rates overall and based on patients' individual characteristics. Past behavioral science interventions have shown promise in increasing flu vaccinations. For example, successful interventions have encouraged people to make concrete plans for when they will get a flu vaccination (Milkman et al. 2011), sent automated calls or text messages reminding patients to get a flu vaccination (Cutrona et al. 2018; Regan et al. 2017), or provided financial incentives for getting vaccinated (Nowalk et al. 2010). Although these results are promising, these studies have been conducted in isolation on different populations, which makes it difficult to compare their interventions' effectiveness or to have enough power to reliably detect differing responses to interventions based on individual characteristics. This research will simultaneously test 19 different SMS interventions to increase flu vaccinations in a "mega-study" and apply machine learning to identify which interventions work best for whom. The interventions are designed by behavioral science experts from the Behavior Change for Good Initiative (BCFG), Penn Medicine Nudge Unit (PMNU), and Geisinger Behavioral Insights Team (BIT). We expect to include at least 80,000 participants. The specific aims of this research are to identify (1) which behavioral science strategies effectively increase flu vaccination rates overall, and (2) which strategies are most effective for different subgroups (e.g., based on age, gender, race).

Study Type

INTERVENTIONAL

Allocation

RANDOMIZED

Purpose

HEALTH_SERVICES_RESEARCH

Masking

DOUBLE

Enrollment

74,811

Conditions

Eligibility

Sex: ALLMin age: 18 YearsHealthy volunteers:

Medical Language ↔ Plain English

Penn Medicine and Geisinger patients will be included if they: Inclusion Criteria: * Have a cell phone number recorded in a Penn Medicine or Geisinger database * Have a new or routine primary care appointment during the study recruitment period (not a sick visit) Exclusion Criteria: * Have documentation of allergy or adverse event to influenza vaccination in medical records * Have documentation of already receiving their 2020 influenza vaccination prior to randomization in medical records * Have opted out of receiving text message appointment reminders * Have asked not to be contacted for research purposes * Have an appointment with someone other than their primary care physician * Have an appointment with someone other than a physician, resident, nurse practitioner, or physician assistant We will recruit as many patients as possible starting in September 2020. We will stop enrolling participants with appointments scheduled to occur after December 31, 2020 if we have reached 4,000 participants per condition. If we do not have 4,000 participants per condition by December 31, 2020, we will continue enrolling participants until we have reached 4,000 per condition, or until March 31, 2021 (discontinuing enrollment at whichever milestone arrives sooner - 4,000 people enrolled or 3/31/21).

Outcomes

Primary Outcomes

Number of Participants With Flu Shot Receipt at or Before Appointment

Our field experiment will be conducted with Penn Medicine and Geisinger Health patients via SMS messages sent prior to their first primary care appointment during the study period, hereafter referred to as the "target appointment." The key dependent variable is whether participants receive a flu shot at or before their target appointment (as recorded in their electronic health records). If participants 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 primary care appointment becomes the target appointment. Participants who have been randomized to a treatment will be counted as not having received a flu shot if they cancel or do not show up for their target appointment and do not schedule a new appointment during the study period. Participants who receive a flu shot before they receive the SMS intervention will be excluded from the analyses.

Time frame: The dependent variable will be assessed during a 4-day period after randomization starting three days prior to the participant's target primary care appointment through the date of the target appointment (including the date of the appointment)

Secondary Outcomes

Number of Participants With Flu Shot Receipt Before March 31, 2021

The secondary dependent variable is whether participants receive the flu shot at or before their target appointment or at any time after this appointment (by March 31, 2021), as recorded in their electronic health records. Participants who receive a flu shot before they receive the SMS intervention will be excluded from the analyses.

Time frame: Up to 6 months after randomization.