Covid19, Vaccine Refusal
Conditions
Brief summary
This study aims to increase uptake of the COVID booster vaccine through messaging informed by Construal Level Theory. Patients in the Mass General Brigham (MGB) health system aged 18 and older who are eligible for the COVID booster vaccine, but who have not yet received a dose at the time of an upcoming primary care clinic visit, will be randomized to one of three messaging arms: 1) why messaging, 2) how messaging, or 3) standard of care (usual care). Messages will be sent via the electronic patient portal a few days in advance of their office visit. The primary outcome will be the rate of booster vaccination at the targeted visit. The secondary outcome will be the rate of receipt of a COVID booster vaccine within 6 weeks of the targeted visit. Subgroup analyses to assess for any association of patient characteristics with intervention responsiveness will be exploratory.
Interventions
BEHAVIORALMessaging informed by construal level theory
Messages are informed by construal level theory, which suggests that emphasizing why elicits more abstract thinking, or high-level construals, and can induce an emotional mindset, which could challenge an individual's sense of identity, autonomy, or political preferences. Conversely, emphasizing how is more cognitive and evokes concrete thinking, or low-level construals, and encourages a planning or implementation mindset, which may be better for encouraging vaccine uptake.
BEHAVIORALUsual Care
Usual messaging sent by Mass General Brigham
Sponsors
National Institute on Aging (NIA)
Brigham and Women's Hospital
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
HEALTH_SERVICES_RESEARCH
Masking
SINGLE (Outcomes Assessor)
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No
Inclusion criteria
* Patients in the Mass General Brigham system * Aged 18 and older * Are eligible for the COVID booster vaccine but have not received a dose at time of upcoming primary care clinic visit
Exclusion criteria
* Documented allergy to a COVID vaccine or its components * Home address outside of Massachusetts * Did not receive full set of primary COVID-19 vaccination series
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Number of Participants Who Received a Booster Vaccination Through the Targeted Visit | 2-5 days | Number of participants who received one dose of a COVID booster vaccine between randomization through the date of the scheduled visit, determined through electronic health records. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Number of Participants Who Received a Booster Vaccination Within 6 Weeks of the Targeted Visit | 6 weeks after the target visit | Number of participants who received one dose of a COVID booster vaccine between randomization through 6 weeks after the targeted visit, determined through electronic health records. |
Countries
United States
Participant flow
Pre-assignment details
The three patient deaths reported here occurred after randomization but before the study intervention could be administered, and so are excluded from primary analyses. In addition, 3 patients were excluded from the primary analysis for not meeting eligibility criteria. Thus the primary analysis consisted of 3665 patients.
Participants by arm
| Arm | Count |
|---|---|
| Why Messaging In this arm, patients will be sent an electronic patient portal message a few days in advance of their office visit. Messages will focus on reasons to get the COVID booster vaccine, including protecting self and loved ones or the idea of herd immunity.
Messaging informed by construal level theory: Messages are informed by construal level theory, which suggests that emphasizing why elicits more abstract thinking, or high-level construals, and can induce an emotional mindset, which could challenge an individual's sense of identity, autonomy, or political preferences. Conversely, emphasizing how is more cognitive and evokes concrete thinking, or low-level construals, and encourages a planning or implementation mindset, which may be better for encouraging vaccine uptake. | 1,199 |
| How Messaging In this arm, patients will be sent an electronic patient portal message a few days in advance of their office visit. How messages will focus on the details of obtaining a vaccination at MGB, what to expect, and how to prepare for the visit.
Messaging informed by construal level theory: Messages are informed by construal level theory, which suggests that emphasizing why elicits more abstract thinking, or high-level construals, and can induce an emotional mindset, which could challenge an individual's sense of identity, autonomy, or political preferences. Conversely, emphasizing how is more cognitive and evokes concrete thinking, or low-level construals, and encourages a planning or implementation mindset, which may be better for encouraging vaccine uptake. | 1,249 |
| Usual Care In this arm, patients will not receive any additional message about their upcoming visit, beyond what they already receive by the health system.
Usual Care: Usual messaging sent by Mass General Brigham | 1,217 |
| Total | 3,665 |
Withdrawals & dropouts
| Period | Reason | FG000 | FG001 | FG002 |
|---|---|---|---|---|
| Overall Study | Death after randomization but before intervention could have been administered | 0 | 2 | 1 |
| Overall Study | Did not meet eligibility criteria | 1 | 1 | 1 |
Baseline characteristics
| Characteristic | Total | Usual Care | How Messaging | Why Messaging |
|---|---|---|---|---|
| Age, Continuous | 53.5 years STANDARD_DEVIATION 17.3 | 53.40 years STANDARD_DEVIATION 16.96 | 53.80 years STANDARD_DEVIATION 17.36 | 53.23 years STANDARD_DEVIATION 17.46 |
| Baseline vaccinations, N(%) Ever received a zoster vaccine *if age >50) | 1025 participants | 322 participants | 374 participants | 329 participants |
| Baseline vaccinations, N(%) Ever received pneumonia vaccine (if age >65) | 878 participants | 285 participants | 306 participants | 287 participants |
| Baseline vaccinations, N(%) Flu shot in the past year | 1661 participants | 537 participants | 582 participants | 542 participants |
| Baseline vaccinations, N(%) Tetanus vaccine in last 10 years | 2944 participants | 985 participants | 997 participants | 962 participants |
| Ethnicity (NIH/OMB) Hispanic or Latino | 975 Participants | 329 Participants | 322 Participants | 324 Participants |
| Ethnicity (NIH/OMB) Not Hispanic or Latino | 2367 Participants | 768 Participants | 830 Participants | 769 Participants |
| Ethnicity (NIH/OMB) Unknown or Not Reported | 323 Participants | 120 Participants | 97 Participants | 106 Participants |
| Race (NIH/OMB) American Indian or Alaska Native | 3 Participants | 0 Participants | 2 Participants | 1 Participants |
| Race (NIH/OMB) Asian | 148 Participants | 51 Participants | 48 Participants | 49 Participants |
| Race (NIH/OMB) Black or African American | 264 Participants | 99 Participants | 91 Participants | 74 Participants |
| Race (NIH/OMB) More than one race | 49 Participants | 17 Participants | 17 Participants | 15 Participants |
| Race (NIH/OMB) Native Hawaiian or Other Pacific Islander | 0 Participants | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Unknown or Not Reported | 993 Participants | 332 Participants | 325 Participants | 336 Participants |
| Race (NIH/OMB) White | 2208 Participants | 718 Participants | 766 Participants | 724 Participants |
| Sex: Female, Male Female | 2166 Participants | 736 Participants | 733 Participants | 697 Participants |
| Sex: Female, Male Male | 1499 Participants | 481 Participants | 516 Participants | 502 Participants |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk | EG002 affected / at risk |
|---|---|---|---|
| deaths Total, all-cause mortality | 2 / 1,200 | 2 / 1,252 | 1 / 1,219 |
| other Total, other adverse events | 0 / 1,199 | 0 / 1,249 | 0 / 1,217 |
| serious Total, serious adverse events | 0 / 1,199 | 0 / 1,249 | 0 / 1,217 |
Outcome results
Primary
Number of Participants Who Received a Booster Vaccination Through the Targeted Visit
Number of participants who received one dose of a COVID booster vaccine between randomization through the date of the scheduled visit, determined through electronic health records.
Time frame: 2-5 days
| Arm | Measure | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|
| Why Messaging | Number of Participants Who Received a Booster Vaccination Through the Targeted Visit | 164 Participants |
| How Messaging | Number of Participants Who Received a Booster Vaccination Through the Targeted Visit | 146 Participants |
| Usual Care | Number of Participants Who Received a Booster Vaccination Through the Targeted Visit | 166 Participants |
Comparison: We used generalized estimating equations with a logit link function and binary-distributed errors, adjusting for clinic-day clustering and including clinic as an adjustment variable for all models. This analysis is otherwise unadjusted.95% CI: [0.67, 1.14]
Comparison: We used generalized estimating equations with a logit link function and binary-distributed errors, adjusting for clinic-day clustering and including clinic as an adjustment variable for all models. This analysis is otherwise unadjusted.95% CI: [0.81, 1.28]
Comparison: We used generalized estimating equations with a logit link function and binary-distributed errors, adjusting for clinic-day clustering and including clinic as an adjustment variable for all models. This analysis is otherwise unadjusted.95% CI: [0.96, 1.51]
Secondary
Number of Participants Who Received a Booster Vaccination Within 6 Weeks of the Targeted Visit
Number of participants who received one dose of a COVID booster vaccine between randomization through 6 weeks after the targeted visit, determined through electronic health records.
Time frame: 6 weeks after the target visit
| Arm | Measure | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|
| Why Messaging | Number of Participants Who Received a Booster Vaccination Within 6 Weeks of the Targeted Visit | 264 Participants |
| How Messaging | Number of Participants Who Received a Booster Vaccination Within 6 Weeks of the Targeted Visit | 231 Participants |
| Usual Care | Number of Participants Who Received a Booster Vaccination Within 6 Weeks of the Targeted Visit | 265 Participants |
Comparison: We used generalized estimating equations with a logit link function and binary-distributed errors, adjusting for clinic-day clustering and including clinic as an adjustment variable for all models. This analysis is otherwise unadjusted.95% CI: [0.67, 1.01]
Comparison: We used generalized estimating equations with a logit link function and binary-distributed errors, adjusting for clinic-day clustering and including clinic as an adjustment variable for all models. This analysis is otherwise unadjusted.95% CI: [0.87, 1.23]
Comparison: We used generalized estimating equations with a logit link function and binary-distributed errors, adjusting for clinic-day clustering and including clinic as an adjustment variable for all models. This analysis is otherwise unadjusted.95% CI: [1.06, 1.49]