Improving Influenza Vaccination Delivery Across a Health System by the Electronic Health Records Patient Portal RCT 5
Phase: NA
Conditions: Influenza, Respiratory Tract Infections
Sponsor: University of California, Los Angeles

Study Title: Improving Influenza Vaccination Delivery Across a Health System by the Electronic 
Health Records Patient Portal RCT 5   
Initial IRB Approval: 12/20/2017 
RCT 5 IRB Approval: 8/18/2022 
Clinical Trials Registration: NCT05525494 
 
 

Protocol 
Brief Summary: 
This trial is taking place in Los Angeles, CA among patients from primary care practices within 
the UCLA Health System. 
Despite the Advisory Committee on Immunization Practices (ACIP) recommendation in 2010 
that all people above 6 months of age should receive an annual flu vaccine, vaccination rates 
remain low. The investigators plan to assess the effectiveness of text and portal reminder/recall 
messages with direct appointment scheduling (pre-appointment, and no pre-appointment) 
encouraging influenza vaccinations sent to patient portal users, as well as the effectiveness of 
tailored portal reminder/recall messages based on responses from pre-commitment prompt 
asking which time and which place they plan to receive their influenza vaccine using a 2 x 2 
nested factorial design. 
Methods and Procedures 
We propose a three-arm randomized controlled trial, and a 2 x 2 nested factorial design within 
the intervention arms. Patients are randomized within UCLA primary care practices into 1) 
receiving text based R/R messages with direct scheduling link, 2) portal-based R/R messages 
with direct scheduling link, or 3) the control group. Patients randomized to the intervention 
arms will receive reminders if they are due for influenza vaccine.  
Nested within the portal reminder arm, we will have two additional components for which 
patients will be randomized separately: 1) A pre-commitment prompt, asking patients which 
time (September, October, November or December) and which place (UCLA, pharmacy, 
workplace or school, or other) they plan to get their Influenza vaccine with tailored monthly 
messages based on responses (pre-commitment message with tailored recall messages with 
direct scheduling vs. standard (“fixed”) portal reminders with direct scheduling); 2) A pre-
appointment reminder encouraging patients to ask for their influenza vaccine at their upcoming 
appointment (pre-appointment reminder encouraging influenza vaccination vs. standard pre-
appointment reminder not mentioning influenza vaccination) 
Nested within the text message reminder arm, we will have one additional component for 
which patients will be randomized separately: 1) A pre-appointment reminder encouraging 
patients to ask for their influenza vaccine at their upcoming appointment (pre-appointment 
reminder encouraging influenza vaccination vs. standard pre-appointment reminder not 
mentioning influenza vaccination). 
Spacing of R/R messages: The pre-commitment prompt will be sent in September, direct 
appointment scheduling and no direct appointment scheduling reminders will be sent one time 
per month until record of vaccine receipt appears in the patient EHR in October, November, 
and December. The pre-appointment reminders will be sent 2-4 days in advance of scheduled 
visits. 

Languages: messages will be in English.   
Health Literacy: We will use plain language <7th grade reading level per Flesch-Kincaid analysis.  
Eligibility: Our EHR will identify subjects who are eligible for either 1 or 2 influenza vaccinations 
based on ACIP algorithms (2 are recommended for children <9 years who have not had prior 
vaccination). 
Inclusion criteria 
Inclusion criteria will involve-- all UCLA primary care patients over 4 months of age who have 
made at least 1 visit to the practice within the prior 3 years and who have signed up for 
MyUCLAhealth (UCLA’s portal) and have used the portal at least once within 12 months, from 
these patients, index patients per household will be randomly selected. 
a. Active patient: We selected >1 visit in 3y based on our prior studies and the literature to 
focus the intervention on active patients; practices do not have a good mechanism to inactivate 
patients.  
b. Focusing on Portal Users: We can only send portal R/R messages to patients who have signed 
up for the portal. Since some patients sign up for the portal but never use it we will restrict our 
inclusion criteria to patients who used the portal within 12m (75% of UCLA patients). This 
standard has been applied before. We will assess intervention effects for the included 
population, and also for the entire practice, since the impact of the intervention reflects the 
extent of portal penetration.  
Exclusion criteria 
Patients will be excluded if they are not a patient at one of the 67 primary care practices within 
UCLA’s Health System, and/or if they do not meet the above specified requirements for being 
an active patient or portal user. 
Main Outcomes and Measures 
Primary Measures:  
1) Receipt of >1 influenza vaccine among index patients between 9/1/2022-4/1/2023 as 
documented in the EHR which is supplemented electronically by the health system with 
influenza vaccination data from external sources (e.g., pharmacies) and claims data.   
2) Receipt of >1 influenza vaccine among pediatric index patients between 9/1/2022-
4/1/2023 as documented in the EHR which is supplemented electronically by the health 
system with influenza vaccination data from external sources (e.g., pharmacies) and 
claims data.   
Secondary Measures: Receipt of annual influenza vaccine between 9/1/2022-4/1/2023 among 
all included patients in identified households. 

 
Study Arm 
Intervention/Treatment 
Active Comparator: Text Fixed R/R 
Messages with Direct Appointment 
Schedule Link + Text Pre-Appointment 
Reminders 
Participants in this arm will receive up to 3 
R/R messages by text. R/R message will be 
sent with a Direct Appointment Scheduling 
link and instructions to make a flu vaccine 
appointment. Participants will receive a Pre-
Appointment Reminder via text when they 
schedule a visit during the study period. 
 
Behavioral: Text Fixed R/R Messages with 
Direct Appointment Schedule Link 
Participants in this arm will receive up to 3 R/R 
messages by text. R/R message will be sent with 
a Direct Appointment Scheduling link and 
instructions to make a flu vaccine appointment. 
 
Behavioral: Text Pre-Appointment Reminder 
Participants will receive a Pre-Appointment 
Reminder via text when they schedule a visit 
during the study period. 
Active Comparator: Text Fixed R/R 
Messages with Direct Appointment 
Schedule Link 
Participants in this arm will receive up to 3 
R/R messages by text. R/R message will be 
sent with a Direct Appointment Scheduling 
link and instructions to make a flu vaccine 
appointment. 
 
Behavioral: Text Fixed R/R Messages with 
Direct Appointment Schedule Link 
Participants in this arm will receive up to 3 R/R 
messages by text. R/R message will be sent with 
a Direct Appointment Scheduling link and 
instructions to make a flu vaccine appointment. 
Active Comparator: Portal Pre-Commitment 
Prompt, Tailored R/R Messages w/ Direct 
Scheduling + Pre-Appointment Reminders 
Participants in this arm will receive a pre-
commitment prompt message by portal in 
September. Tailored R/R messages will be 
sent monthly by portal based on time and 
place selected by patients (up to 3). R/R 
message will be sent with a Direct 
Appointment Scheduling link and instructions 
to make a flu vaccine appointment. 
Participants will receive a Pre-Appointment 
Reminder advising them to ask their doctor 
for the flu vaccine at their upcoming 
appointment via portal when they schedule a 
visit during the study period. 
 
Behavioral: Portal Pre-Commitment Prompt 
with Tailored R/R Messages with Direct 
Appointment Schedule Link 
Participants in this arm will receive a pre-
commitment prompt message by portal in 
September. Tailored R/R messages will be sent 
monthly by portal based on time and place 
selected by patients (up to 3). R/R message will 
be sent with a Direct Appointment Scheduling 
link and instructions to make a flu vaccine 
appointment. 
 
 
Behavioral: Portal Pre-Appointment Reminder 
Participants will receive a Pre-Appointment 
Reminder advising them to ask their doctor for 
the flu vaccine at their upcoming appointment 

via portal when they schedule a visit during the 
study period. 
 
Active Comparator: Portal Pre-Commitment 
Prompt with Tailored R/R Messages with 
Direct Appointment Schedule Link 
Participants in this arm will receive a pre-
commitment prompt message by portal in 
September. Tailored R/R messages will be 
sent monthly based on time and place 
selected by patients (up to 3). R/R message 
will be sent with a Direct Appointment 
Scheduling link and instructions to make a flu 
vaccine appointment. 
 
Behavioral: Portal Pre-Commitment Prompt 
with Tailored R/R Messages with Direct 
Appointment Schedule Link 
Participants in this arm will receive a pre-
commitment prompt message by portal in 
September. Tailored R/R messages will be sent 
monthly by portal based on time and place 
selected by patients (up to 3). R/R message will 
be sent with a Direct Appointment Scheduling 
link and instructions to make a flu vaccine 
appointment. 
 
Active Comparator: Portal Fixed R/R 
Messages with Direct Appointment 
Schedule Link + Portal Pre-Appointment 
Reminder 
Participants in this arm will receive up to 3 
R/R messages by portal. R/R message will be 
sent with a Direct Appointment Scheduling 
link and instructions to make a flu vaccine 
appointment. Participants will receive a Pre-
Appointment Reminder advising them to ask 
their doctor for the flu vaccine at their 
upcoming appointment via portal when they 
schedule a visit during the study period. 
 
Behavioral: Portal Fixed R/R Messages with 
Direct Appointment Schedule Link 
Participants in this arm will receive up to 3 R/R 
messages by portal. R/R message will be sent 
with a Direct Appointment Scheduling link and 
instructions to make a flu vaccine appointment. 
 
Behavioral: Portal Pre-Appointment Reminder 
Participants will receive a Pre-Appointment 
Reminder advising them to ask their doctor for 
the flu vaccine at their upcoming appointment 
via portal when they schedule a visit during the 
study period. 
Active Comparator: Portal Fixed R/R 
Messages with Direct Appointment 
Schedule Link 
Participants in this arm will receive up to 3 
R/R messages by portal. R/R message will be 
sent with a Direct Appointment Scheduling 
link and instructions to make a flu vaccine 
appointment. 
 
Behavioral: Portal Fixed R/R Messages with 
Direct Appointment Schedule Link 
Participants in this arm will receive up to 3 R/R 
messages by portal. R/R message will be sent 
with a Direct Appointment Scheduling link and 
instructions to make a flu vaccine appointment. 
No Intervention: No R/R Message or Pre-
Appointment Reminder 
 

Participants do not receive any flu vaccine 
R/R message or Pre-Appointment Reminder 
advising them to ask their doctor for the flu 
vaccine at their upcoming appointment 
during the specified flu season.