Trial Outcomes & Findings for PROmotion of COVID-19 BOOSTer VA(X)Ccination in the Emergency Department - PROBOOSTVAXED (NCT NCT06156215)
NCT ID: NCT06156215
Last Updated: 2025-09-12
Results Overview
Our primary outcome is booster vaccine uptake (at any vaccination location) within 30 days after participants' index ED visit, comparing Intervention M arm with Control
Recruitment status
COMPLETED
Study phase
NA
Target enrollment
919 participants
Primary outcome timeframe
30 days
Results posted on
2025-09-12
Participant Flow
919 participants were randomized
Participant milestones
| Measure |
Ben Taub Hospital
First condition: control
|
Duke University Hospital
First condition: Control
|
Jefferson University Hospital
First Condition: Control
|
Jefferson Methodist Hospital
First Condition: Intervention Q
|
UCSF Parnassus Medical Center
First condition: Intervention Q
|
Zuckerberg San Francisco General Hospital
First Condition: Intervention Q
|
|---|---|---|---|---|---|---|
|
Overall Study
STARTED
|
132
|
147
|
294
|
3
|
169
|
174
|
|
Overall Study
Randomized to Intervention M
|
34
|
50
|
84
|
0
|
37
|
63
|
|
Overall Study
Randomized to Intervention Q
|
52
|
43
|
84
|
1
|
71
|
56
|
|
Overall Study
Randomized to Control
|
46
|
54
|
126
|
2
|
61
|
55
|
|
Overall Study
COMPLETED
|
118
|
140
|
279
|
3
|
158
|
154
|
|
Overall Study
NOT COMPLETED
|
14
|
7
|
15
|
0
|
11
|
20
|
Reasons for withdrawal
| Measure |
Ben Taub Hospital
First condition: control
|
Duke University Hospital
First condition: Control
|
Jefferson University Hospital
First Condition: Control
|
Jefferson Methodist Hospital
First Condition: Intervention Q
|
UCSF Parnassus Medical Center
First condition: Intervention Q
|
Zuckerberg San Francisco General Hospital
First Condition: Intervention Q
|
|---|---|---|---|---|---|---|
|
Overall Study
Withdrawal by Subject
|
2
|
4
|
4
|
0
|
2
|
2
|
|
Overall Study
Left ED without completing study
|
9
|
3
|
9
|
0
|
8
|
16
|
|
Overall Study
Physician Decision
|
1
|
0
|
0
|
0
|
0
|
0
|
|
Overall Study
Became or found ineligible
|
2
|
0
|
2
|
0
|
1
|
2
|
Baseline Characteristics
PROmotion of COVID-19 BOOSTer VA(X)Ccination in the Emergency Department - PROBOOSTVAXED
Baseline characteristics by cohort
| Measure |
PROBOOSTVAXED Intervention M (Messaging + Vaccine Question)
n=247 Participants
* Vaccine messaging
* Vaccine acceptance question
Vaccine Messaging: 1) Video clips - short (approximately 3-minute) Public Service Announcement type videos to be viewed by participant using a QR code on their smartphone. If no smartphone is available, the video will be shown to the participant on an iPad.
2\) Printed materials - one page information sheets handed to subjects by CRCs. 3) Face to face messaging - short (\< 1 minute), scripted message from the patient's providers in the ED (nurse or provider)
Each site will maintain a library of
A. 5 versions of the videos - the version used in any participant will be tailored to that participant's stated race/ethnicity.
B. 5 versions of printed flyers - likewise, the version will be tailored to the participant's stated race/ethnicity.
C. 1 version of scripted message to be delivered in English or Spanish.
Vaccine Acceptance Question: The last question in the Vaccine Acceptance Survey in both the Intervention M and Intervention Q arms of the study is "Would you accept the COVID-19 booster vaccine in the emergency department today if your doctor asked you?"
|
Intervention Q (Vaccine Question, No Messaging)
n=273 Participants
* No vaccine messaging
* Vaccine acceptance question asked in the Vaccine Acceptance Survey
Vaccine Acceptance Survey: We will administer the Vaccine Acceptance Survey at some time (generally 30 minutes but up to 3 hours) after the Intake Survey. The surveys in the control group retain the same key primary and secondary outcome questions as in the intervention group Vaccine Acceptance surveys.
Vaccine Acceptance Question: The last question in the Vaccine Acceptance Survey in both the Intervention M and Intervention Q arms of the study is "Would you accept the COVID-19 booster vaccine in the emergency department today if your doctor asked you?"
|
Control (No Messaging, No Vaccine Question)
n=332 Participants
* No vaccine messaging
* No vaccine acceptance question
The workflow during this arm is identical to the Intervention Q arm except there will be no Vaccine Acceptance Question survey.
|
Total
n=852 Participants
Total of all reporting groups
|
|---|---|---|---|---|
|
Age, Continuous
|
46 years
n=93 Participants
|
49 years
n=4 Participants
|
46 years
n=27 Participants
|
46.5 years
n=483 Participants
|
|
Sex/Gender, Customized
Woman
|
136 Participants
n=93 Participants
|
142 Participants
n=4 Participants
|
186 Participants
n=27 Participants
|
464 Participants
n=483 Participants
|
|
Sex/Gender, Customized
Man
|
107 Participants
n=93 Participants
|
129 Participants
n=4 Participants
|
143 Participants
n=27 Participants
|
379 Participants
n=483 Participants
|
|
Sex/Gender, Customized
Other
|
4 Participants
n=93 Participants
|
2 Participants
n=4 Participants
|
3 Participants
n=27 Participants
|
9 Participants
n=483 Participants
|
|
Race/Ethnicity, Customized
Black
|
83 Participants
n=93 Participants
|
85 Participants
n=4 Participants
|
119 Participants
n=27 Participants
|
287 Participants
n=483 Participants
|
|
Race/Ethnicity, Customized
American Indian, Alaska Native
|
3 Participants
n=93 Participants
|
0 Participants
n=4 Participants
|
2 Participants
n=27 Participants
|
5 Participants
n=483 Participants
|
|
Race/Ethnicity, Customized
Asian
|
12 Participants
n=93 Participants
|
20 Participants
n=4 Participants
|
16 Participants
n=27 Participants
|
48 Participants
n=483 Participants
|
|
Race/Ethnicity, Customized
Latinx
|
48 Participants
n=93 Participants
|
61 Participants
n=4 Participants
|
61 Participants
n=27 Participants
|
170 Participants
n=483 Participants
|
|
Race/Ethnicity, Customized
Middle Eastern
|
0 Participants
n=93 Participants
|
0 Participants
n=4 Participants
|
0 Participants
n=27 Participants
|
0 Participants
n=483 Participants
|
|
Race/Ethnicity, Customized
Native hawaiian/ Pacific Islander
|
4 Participants
n=93 Participants
|
4 Participants
n=4 Participants
|
4 Participants
n=27 Participants
|
12 Participants
n=483 Participants
|
|
Race/Ethnicity, Customized
White (non-Latinx)
|
101 Participants
n=93 Participants
|
107 Participants
n=4 Participants
|
137 Participants
n=27 Participants
|
345 Participants
n=483 Participants
|
|
Race/Ethnicity, Customized
Other
|
6 Participants
n=93 Participants
|
8 Participants
n=4 Participants
|
10 Participants
n=27 Participants
|
24 Participants
n=483 Participants
|
|
Region of Enrollment
United States
|
247 participants
n=93 Participants
|
273 participants
n=4 Participants
|
332 participants
n=27 Participants
|
852 participants
n=483 Participants
|
PRIMARY outcome
Timeframe: 30 daysOur primary outcome is booster vaccine uptake (at any vaccination location) within 30 days after participants' index ED visit, comparing Intervention M arm with Control
Outcome measures
| Measure |
PROBOOSTVAXED Intervention M (Messaging + Vaccine Question)
n=247 Participants
* Vaccine messaging
* Vaccine acceptance question
Vaccine Messaging: 1) Video clips - short (approximately 3-minute) Public Service Announcement type videos to be viewed by participant using a QR code on their smartphone. If no smartphone is available, the video will be shown to the participant on an iPad.
2\) Printed materials - one page information sheets handed to subjects by CRCs. 3) Face to face messaging - short (\< 1 minute), scripted message from the patient's providers in the ED (nurse or provider)
Each site will maintain a library of
A. 5 versions of the videos - the version used in any participant will be tailored to that participant's stated race/ethnicity.
B. 5 versions of printed flyers - likewise, the version will be tailored to the participant's stated race/ethnicity.
C. 1 version of scripted message to be delivered in English or Spanish.
Vaccine Acceptance Question: The last question in the Vaccine Acceptance Survey in both the Intervention M and Intervention Q arms of the study is "Would you accept the COVID-19 booster vaccine in the emergency department today if your doctor asked you?"
|
Control (No Messaging, No Vaccine Question)
n=332 Participants
* No vaccine messaging
* No vaccine acceptance question
The workflow during this arm is identical to the Intervention Q arm except there will be no Vaccine Acceptance Question survey.
|
Control (No Messaging, No Vaccine Question)
* No vaccine messaging
* No vaccine acceptance question
The workflow during this arm is identical to the Intervention Q arm except there will be no Vaccine Acceptance Question survey.
|
|---|---|---|---|
|
Number of Participants With 30-day Booster Vaccine Uptake
|
14 Participants
|
10 Participants
|
—
|
SECONDARY outcome
Timeframe: day of index visitBooster vaccine uptake in the ED on the day of the index visit, M arm versus control and Q arm versus control
Outcome measures
| Measure |
PROBOOSTVAXED Intervention M (Messaging + Vaccine Question)
n=247 Participants
* Vaccine messaging
* Vaccine acceptance question
Vaccine Messaging: 1) Video clips - short (approximately 3-minute) Public Service Announcement type videos to be viewed by participant using a QR code on their smartphone. If no smartphone is available, the video will be shown to the participant on an iPad.
2\) Printed materials - one page information sheets handed to subjects by CRCs. 3) Face to face messaging - short (\< 1 minute), scripted message from the patient's providers in the ED (nurse or provider)
Each site will maintain a library of
A. 5 versions of the videos - the version used in any participant will be tailored to that participant's stated race/ethnicity.
B. 5 versions of printed flyers - likewise, the version will be tailored to the participant's stated race/ethnicity.
C. 1 version of scripted message to be delivered in English or Spanish.
Vaccine Acceptance Question: The last question in the Vaccine Acceptance Survey in both the Intervention M and Intervention Q arms of the study is "Would you accept the COVID-19 booster vaccine in the emergency department today if your doctor asked you?"
|
Control (No Messaging, No Vaccine Question)
n=273 Participants
* No vaccine messaging
* No vaccine acceptance question
The workflow during this arm is identical to the Intervention Q arm except there will be no Vaccine Acceptance Question survey.
|
Control (No Messaging, No Vaccine Question)
n=332 Participants
* No vaccine messaging
* No vaccine acceptance question
The workflow during this arm is identical to the Intervention Q arm except there will be no Vaccine Acceptance Question survey.
|
|---|---|---|---|
|
Number or Participants Receiving Booster Vaccination in the ED
|
8 Participants
|
7 Participants
|
0 Participants
|
SECONDARY outcome
Timeframe: on the day of index ED visitA response of "yes" to the question, "Would you accept the booster vaccine in the emergency department today if your doctor asked you?"), comparing M and Q arms
Outcome measures
| Measure |
PROBOOSTVAXED Intervention M (Messaging + Vaccine Question)
n=247 Participants
* Vaccine messaging
* Vaccine acceptance question
Vaccine Messaging: 1) Video clips - short (approximately 3-minute) Public Service Announcement type videos to be viewed by participant using a QR code on their smartphone. If no smartphone is available, the video will be shown to the participant on an iPad.
2\) Printed materials - one page information sheets handed to subjects by CRCs. 3) Face to face messaging - short (\< 1 minute), scripted message from the patient's providers in the ED (nurse or provider)
Each site will maintain a library of
A. 5 versions of the videos - the version used in any participant will be tailored to that participant's stated race/ethnicity.
B. 5 versions of printed flyers - likewise, the version will be tailored to the participant's stated race/ethnicity.
C. 1 version of scripted message to be delivered in English or Spanish.
Vaccine Acceptance Question: The last question in the Vaccine Acceptance Survey in both the Intervention M and Intervention Q arms of the study is "Would you accept the COVID-19 booster vaccine in the emergency department today if your doctor asked you?"
|
Control (No Messaging, No Vaccine Question)
n=273 Participants
* No vaccine messaging
* No vaccine acceptance question
The workflow during this arm is identical to the Intervention Q arm except there will be no Vaccine Acceptance Question survey.
|
Control (No Messaging, No Vaccine Question)
* No vaccine messaging
* No vaccine acceptance question
The workflow during this arm is identical to the Intervention Q arm except there will be no Vaccine Acceptance Question survey.
|
|---|---|---|---|
|
Number of Participants Stating They Would Accept Vaccine in the ED
|
73 Participants
|
90 Participants
|
—
|
SECONDARY outcome
Timeframe: 30 daysBooster vaccine uptake (at any vaccination location) within 30 days after participants' index ED visit, comparing Intervention Q arm with Control
Outcome measures
| Measure |
PROBOOSTVAXED Intervention M (Messaging + Vaccine Question)
n=273 Participants
* Vaccine messaging
* Vaccine acceptance question
Vaccine Messaging: 1) Video clips - short (approximately 3-minute) Public Service Announcement type videos to be viewed by participant using a QR code on their smartphone. If no smartphone is available, the video will be shown to the participant on an iPad.
2\) Printed materials - one page information sheets handed to subjects by CRCs. 3) Face to face messaging - short (\< 1 minute), scripted message from the patient's providers in the ED (nurse or provider)
Each site will maintain a library of
A. 5 versions of the videos - the version used in any participant will be tailored to that participant's stated race/ethnicity.
B. 5 versions of printed flyers - likewise, the version will be tailored to the participant's stated race/ethnicity.
C. 1 version of scripted message to be delivered in English or Spanish.
Vaccine Acceptance Question: The last question in the Vaccine Acceptance Survey in both the Intervention M and Intervention Q arms of the study is "Would you accept the COVID-19 booster vaccine in the emergency department today if your doctor asked you?"
|
Control (No Messaging, No Vaccine Question)
n=332 Participants
* No vaccine messaging
* No vaccine acceptance question
The workflow during this arm is identical to the Intervention Q arm except there will be no Vaccine Acceptance Question survey.
|
Control (No Messaging, No Vaccine Question)
* No vaccine messaging
* No vaccine acceptance question
The workflow during this arm is identical to the Intervention Q arm except there will be no Vaccine Acceptance Question survey.
|
|---|---|---|---|
|
Number of Participants With 30-day Booster Vaccine Uptake, Q Arm
|
11 Participants
|
10 Participants
|
—
|
Adverse Events
PROBOOSTVAXED Intervention M (Messaging + Vaccine Question)
Serious events: 0 serious events
Other events: 0 other events
Deaths: 0 deaths
Intervention Q (Vaccine Question, No Messaging)
Serious events: 0 serious events
Other events: 0 other events
Deaths: 0 deaths
Control (No Messaging, No Vaccine Question)
Serious events: 0 serious events
Other events: 0 other events
Deaths: 0 deaths
Serious adverse events
Adverse event data not reported
Other adverse events
Adverse event data not reported
Additional Information
Dr Melanie Molina
University of California San Francisco
Phone: 512.294.4366
Email: [email protected]
Results disclosure agreements
- Principal investigator is a sponsor employee
- Publication restrictions are in place