InfluenzaLADHSNCT05535777
Patient Portal Flu Vaccine Reminders_RCT 5 (LADHS)
A study testing Enhanced texts with Callback by a Person and Enhanced Bidirectional Texts in people with Influenza and Respiratory Tract Infections, run by University of California, Los Angeles at 2 sites in United States.
Trial summary
This trial is taking place in Los Angeles, CA at clinics within the Los Angeles Department of Health clinics. The study design is a comparative effectiveness trial design. Patients will be randomized into 1) receiving enhanced texting with a callback by a trained call-center staff member to schedule a vaccine visit if… Read more about this study
- Who is it for?
- Ages 6 months and older
- Conditions the study is for
- Influenza, Respiratory Tract Infections
- What is being tested?
- Enhanced texts with Callback by a Person and Enhanced Bidirectional Texts
- Type of treatment
- Vaccines, Lifestyle or therapy programme
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 246,295 participants
- Where
- 2 sitesUnited States
- Study dates
- 13 Sep 2022to 31 Mar 2023
- Phase
- Interventional
- Are there results?
- Yes, posted in the registrySummary in the doctors' view
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 6 months and older
- All sexes
- No healthy volunteers
- Child, Adult, Older adult
Who may be able to join
- LADHS patients identified as primary care patients assigned as follows: (1) assigned through managed care plans, (2) self-pay but linked with a provider, or (3) uninsured but assigned.
Who cannot join
- LADHS patient not identified as a primary care patient.
Trial locations and contacts
2 sites in 1 country.
United States2 sites
Los Angeles County Department of Health Services
Los Angeles, California, 90012
University of California, Los Angeles
Los Angeles, California, 99095
About this study
Official title: Improving Influenza Vaccination Delivery Across a Health System by the Electronic Health Records Patient Portal RCT 5 (LADHS)
This trial is taking place in Los Angeles, CA at clinics within the Los Angeles Department of Health clinics.
The study design is a comparative effectiveness trial design. Patients will be randomized into 1) receiving enhanced texting with a callback by a trained call-center staff member to schedule a vaccine visit if the patient presses "1" in response to the text, 2) receiving enhanced bidirectional texting with a texting response from a trained call-center staff member who will help the patient schedule a vaccine visit through a series of back-and-forth texts, or 3) standard text reminders (control group). Patients in all arms will receive reminders if they are due for influenza vaccine.
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: at 6m-4.9 yrs. (70%), 5-17.9 yrs. (56%), 18-64.9 yrs. (38%), and >65 yrs. (63%). The investigators will assess the effectiveness of enhanced text R/R messages as compared to the standard of care control (standard text reminders).
Read the detailed description
Sub-optimal vaccination rates are a significant problem in the U.S., despite their effectiveness in preventing morbidity and mortality from vaccine-preventable illness. For influenza specifically, annual epidemics of influenza cause substantial morbidity in the U.S. with up to 40,00-80,000 deaths/year and many hospitalizations, emergency and outpatient visits, and significant costs.
Reminder/recall (R/R), sent by phone, mail or other modality, can improve child and adult influenza vaccination rates. However, the majority of pediatric or adult primary care practices do not conduct R/R. Barriers are lack of finances, personnel, and algorithms to identify eligible patients.
A technological breakthrough that might overcome these barriers involves patient text messaging at the health system level.
This randomized controlled trial will assess the effectiveness of reminders messages sent by text encouraging influenza vaccination, on increasing influenza vaccination rates within a health system. Patients will be randomized into three groups: 1) one-third of patients will receive enhanced text reminder messages, 2) one-third will receive enhanced bidirectional text reminder messages and 3) one-third will received standard-of-care text reminder messages.
Enhanced texts - Callback by a person: Patient randomized to this study arm will receive a phone call back by a call center agent if they press "1" in response to a question on the original text message. The call center agent's job is to schedule patients for clinical visits. These call center agents will be trained by our faculty and staff and will have the usual HIPAA and other patient confidentiality training.
Enhanced Bidirectional Texts: These texts are designed to help schedule a vaccine visit. Patients randomized to this study arm will receive a text message from a call center agent if they press "1" in response to a question on the original text message. The bidirectional texts will have an agent who can answer questions and schedule an appointment through text message back-and-forth conversations with the patient. Bidirectional texts will be exchanged on a HIPAA compliant bidirectional text messaging platform. The patient will use the regular SMS function on their cellphone and the agent will receive and respond to the bidirectional text on the HIPAA compliant platform.
Previous studies have shown that low-cost, behavioral nudges through texting can increase influenza vaccination uptake compared to usual care. However, there are limited studies that evaluate the effect of decreasing friction/barriers to scheduling especially within safety net populations. This study will examine the effect of strategies to reduce friction/barriers to scheduling including bidirectional text messages, and texts for patients to call for direct scheduling without wait time on influenza vaccination rates in adults within the 2022-2023 flu season.
For the primary analysis, the primary outcome will be the patient's end of flu season vaccination status. Intervention effects will be assessed using multivariable log-binomial regression models. Regressions will include indicators for each intervention as fixed effects, with the standard text condition as the reference group, and potentially clinic random effects, depending on retrospective analysis results. Models will also adjust for patient age, gender, race/ethnicity, insurance, and whether the patient was vaccinated in at least one of the prior two flu seasons.
The enhanced texts with callback, enhanced bidirectional texts, and standard-of-care text reminder messages will begin in September of 2022.
- Conditions
- Influenza, Respiratory Tract Infections
- Being tested
- Enhanced texts with Callback by a Person, Enhanced Bidirectional Texts
- Keywords
- Reminder Recall (R/R), Influenza Vaccine, Electronic Health Record, Text Message, Vaccine
- Medical subject headings
- Influenza, Human, Respiratory Tract Infections
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Enhanced texts with Callback by a PersonBehavioural
Enhanced texts - Callback by a person: Patient randomized to this study arm will receive a phone call back by a call center agent if they press "1" in response to a question on the original text message. The call center agent's job is to schedule patients for clinical visits. These call center agents will be trained by our faculty and staff and will have the usual HIPAA and other patient confidentiality training.
Enhanced Bidirectional TextsBehavioural
Patients randomized to this study arm will receive a text message from a call center agent if they press "1" in response to a question on the original text message. The bidirectional texts will have an agent who can answer questions and schedule an appointment through text message back-and-forth conversations with the patient.
| Study group | Role | What they receive |
|---|---|---|
| Enhanced Text Reminders with Callback by Person | Active comparator | Participants in this arm will receive up to 3 R/R messages by text. R/R message will receive a phone call back by a call center agent if they press "1" in response to a question on the original text message. The call center agent's job is to schedule patients for clinical visits. These call center agents will be trained by our faculty and staff and will have the usual HIPAA and other patient confidentiality training. Receives: Behavioral: Enhanced texts with Callback by a Person |
| Enhanced Bidirectional Text Reminders | Active comparator | Participants in this arm will receive a text message from a call center agent if they press "1" in response to a question on the original text message. The bidirectional texts will have an agent who can answer questions and schedule an appointment through text message back-and-forth conversations with the patient. Bidirectional texts will be exchanged on a HIPAA compliant bidirectional text messaging platform. The patient will use the regular SMS function on their cellphone and the agent will receive and respond to the bidirectional text on the HIPAA compliant platform. Receives: Behavioral: Enhanced Bidirectional Texts |
| Standard Text Reminders | No intervention | Participants in this arm will receive up to 3 text messages, reminding them about the importance of influenza vaccination. The standard texts will include a clinic call back number and patient portal self-scheduling for patients to schedule their influenza vaccines. The direct scheduling texts includes a direct number to an agent that can help schedule and answer questions on the phone in real time. The texts with a direct number to schedule will link a specified phone number to call and schedule. This number would be answered by a central agent quickly and a patient could schedule their flu shot at any clinic site. This specific phone number would not go through the multiple option menus a patient would normally experience when calling their clinic. |
What is being measured
The primary outcome is the main question the study is designed to answer.
Receipt of the Annual Influenza Vaccine Among Adult and Pediatric Index Patients
Percent of patients with annual influenza vaccination (between 9/1/22 - 4/1/23) among adult and pediatric index patients. Outcomes will be assessed via vaccine data extraction from the electronic health record and external claims and pharmacy data.
The index patients must be an LADHS patient. Primary care patients who are empaneled to a primary care provider within DHS are assigned as follows: (1) assigned through managed care plans, (2) self-pay but linked with a provider or (3) uninsured but assigned). Individuals not affiliated with any primary care practice will be excluded from the primary analysis.
Measured: 6 months
Secondary outcomes (1)
Receipt of the Annual Influenza Vaccine Among Pediatric Index Patients
Percent of patients with annual influenza vaccination (between 9/1/22 - 4/1/23) among pediatric index patients. Outcomes will be assessed via vaccine data extraction from the electronic health record and external claims and pharmacy data.
The index patients must be an LADHS patient. Primary care patients who are empaneled to a primary care provider within DHS are assigned as follows: (1) assigned through managed care plans, (2) self-pay but linked with a provider or (3) uninsured but assigned). Individuals not affiliated with any primary care practice will be excluded from the primary analysis.
Measured: 6 months
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted10 Sep 2022
- Study start13 Sep 2022
- Primary completion31 Mar 2023
- Study completion31 Mar 2023
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Posted resultsParticipant flow, outcome measures and adverse events reported by the sponsor.
- Other trials for InfluenzaStudies of the same condition, open and under way.
- More trials run by University of California, Los AngelesThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Health services research
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Model description
- Pragmatic comparative effectiveness trial with a standard-of-care control group
- Masking
- Single blind
- Who is masked
- Participant
- Enrolment
- 246,295 participants (actual)
Sponsor and investigators
- Lead sponsor
- University of California, Los Angeles
- Sponsor type
- University, hospital or other
- Collaborators
- National Institute of Allergy and Infectious Diseases (NIAID), Los Angeles County Department of Public Health
- Responsible party
- Principal investigator, Peter G Szilagyi, MD MPH, University of California, Los Angeles
- Investigators
- Peter Szilagyi, Principal investigator, University of California, Los Angeles
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05535777
- Sponsor's protocol ID
- 17-001889-00016 (LADHS)
- Other IDs
- R01AI135029
- Acronym
- LADHS
- Status last verified
- Mar 2025
- First submitted
- 6 Sep 2022
- Last updated
- 11 Apr 2025
- Results posted
- Yes, on ClinicalTrials.gov
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 11 Apr 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Improving Influenza Vaccination Delivery Across a Health System by the Electronic Health Records Patient Portal RCT 5 (LADHS)
- ClinicalTrials.gov ID
- NCT05535777
- Acronym / sponsor ID
- LADHS / 17-001889-00016 (LADHS)
- Conditions
- Influenza, Respiratory Tract Infections
- Keywords
- Reminder Recall (R/R), Influenza Vaccine, Electronic Health Record, Text Message, Vaccine
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 246,295 participants (actual)
- Lead sponsor
- University of California, Los AngelesUniversity, hospital or other
- Collaborators
- National Institute of Allergy and Infectious Diseases (NIAID), Los Angeles County Department of Public Health
- Study start
- 13 Sep 2022 (actual)
- Primary completion
- 31 Mar 2023 (actual)
- Study completion
- 31 Mar 2023 (actual)
- First posted
- 10 Sep 2022 (actual)
- Results
- Posted 11 Apr 2025
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
This trial is taking place in Los Angeles, CA at clinics within the Los Angeles Department of Health clinics.
The study design is a comparative effectiveness trial design. Patients will be randomized into 1) receiving enhanced texting with a callback by a trained call-center staff member to schedule a vaccine visit if the patient presses "1" in response to the text, 2) receiving enhanced bidirectional texting with a texting response from a trained call-center staff member who will help the patient schedule a vaccine visit through a series of back-and-forth texts, or 3) standard text reminders (control group). Patients in all arms will receive reminders if they are due for influenza vaccine.
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: at 6m-4.9 yrs. (70%), 5-17.9 yrs. (56%), 18-64.9 yrs. (38%), and >65 yrs. (63%). The investigators will assess the effectiveness of enhanced text R/R messages as compared to the standard of care control (standard text reminders).
Detailed description
Sub-optimal vaccination rates are a significant problem in the U.S., despite their effectiveness in preventing morbidity and mortality from vaccine-preventable illness. For influenza specifically, annual epidemics of influenza cause substantial morbidity in the U.S. with up to 40,00-80,000 deaths/year and many hospitalizations, emergency and outpatient visits, and significant costs.
Reminder/recall (R/R), sent by phone, mail or other modality, can improve child and adult influenza vaccination rates. However, the majority of pediatric or adult primary care practices do not conduct R/R. Barriers are lack of finances, personnel, and algorithms to identify eligible patients.
A technological breakthrough that might overcome these barriers involves patient text messaging at the health system level.
This randomized controlled trial will assess the effectiveness of reminders messages sent by text encouraging influenza vaccination, on increasing influenza vaccination rates within a health system. Patients will be randomized into three groups: 1) one-third of patients will receive enhanced text reminder messages, 2) one-third will receive enhanced bidirectional text reminder messages and 3) one-third will received standard-of-care text reminder messages.
Enhanced texts - Callback by a person: Patient randomized to this study arm will receive a phone call back by a call center agent if they press "1" in response to a question on the original text message. The call center agent's job is to schedule patients for clinical visits. These call center agents will be trained by our faculty and staff and will have the usual HIPAA and other patient confidentiality training.
Enhanced Bidirectional Texts: These texts are designed to help schedule a vaccine visit. Patients randomized to this study arm will receive a text message from a call center agent if they press "1" in response to a question on the original text message. The bidirectional texts will have an agent who can answer questions and schedule an appointment through text message back-and-forth conversations with the patient. Bidirectional texts will be exchanged on a HIPAA compliant bidirectional text messaging platform. The patient will use the regular SMS function on their cellphone and the agent will receive and respond to the bidirectional text on the HIPAA compliant platform.
Previous studies have shown that low-cost, behavioral nudges through texting can increase influenza vaccination uptake compared to usual care. However, there are limited studies that evaluate the effect of decreasing friction/barriers to scheduling especially within safety net populations. This study will examine the effect of strategies to reduce friction/barriers to scheduling including bidirectional text messages, and texts for patients to call for direct scheduling without wait time on influenza vaccination rates in adults within the 2022-2023 flu season.
For the primary analysis, the primary outcome will be the patient's end of flu season vaccination status. Intervention effects will be assessed using multivariable log-binomial regression models. Regressions will include indicators for each intervention as fixed effects, with the standard text condition as the reference group, and potentially clinic random effects, depending on retrospective analysis results. Models will also adjust for patient age, gender, race/ethnicity, insurance, and whether the patient was vaccinated in at least one of the prior two flu seasons.
The enhanced texts with callback, enhanced bidirectional texts, and standard-of-care text reminder messages will begin in September of 2022.
Study design
- Primary purpose
- Health services research
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Single blind (participant)
- Number of arms
- 3
- Model description
- Pragmatic comparative effectiveness trial with a standard-of-care control group
| Arm | Type | Receives |
|---|---|---|
| Enhanced Text Reminders with Callback by Person | Active comparator | Behavioral: Enhanced texts with Callback by a PersonParticipants in this arm will receive up to 3 R/R messages by text. R/R message will receive a phone call back by a call center agent if they press "1" in response to a question on the original text message. The call center agent's job is to schedule patients for clinical visits. These call center agents will be trained by our faculty and staff and will have the usual HIPAA and other patient confidentiality training. |
| Enhanced Bidirectional Text Reminders | Active comparator | Behavioral: Enhanced Bidirectional TextsParticipants in this arm will receive a text message from a call center agent if they press "1" in response to a question on the original text message. The bidirectional texts will have an agent who can answer questions and schedule an appointment through text message back-and-forth conversations with the patient. Bidirectional texts will be exchanged on a HIPAA compliant bidirectional text messaging platform. The patient will use the regular SMS function on their cellphone and the agent will receive and respond to the bidirectional text on the HIPAA compliant platform. |
| Standard Text Reminders | No intervention | –Participants in this arm will receive up to 3 text messages, reminding them about the importance of influenza vaccination. The standard texts will include a clinic call back number and patient portal self-scheduling for patients to schedule their influenza vaccines. The direct scheduling texts includes a direct number to an agent that can help schedule and answer questions on the phone in real time. The texts with a direct number to schedule will link a specified phone number to call and schedule. This number would be answered by a central agent quickly and a patient could schedule their flu shot at any clinic site. This specific phone number would not go through the multiple option menus a patient would normally experience when calling their clinic. |
Who may qualify
- Ages
- 6 months and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Child, Adult, Older adult
Key inclusion criteria (1 listed)
- LADHS patients identified as primary care patients assigned as follows: (1) assigned through managed care plans, (2) self-pay but linked with a provider, or (3) uninsured but assigned.
Key exclusion criteria (1 listed)
- LADHS patient not identified as a primary care patient.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Enhanced texts with Callback by a PersonEnhanced texts - Callback by a person: Patient randomized to this study arm will receive a phone call back by a call center agent if they press "1" in response to a question on the original text message. The call center agent's job is to schedule patients for clinical visits. These call center agents will be trained by our faculty and staff and will have the usual HIPAA and other patient confidentiality training. | Behavioural | Enhanced Text Reminders with Callback by Person |
| Enhanced Bidirectional TextsPatients randomized to this study arm will receive a text message from a call center agent if they press "1" in response to a question on the original text message. The bidirectional texts will have an agent who can answer questions and schedule an appointment through text message back-and-forth conversations with the patient. | Behavioural | Enhanced Bidirectional Text Reminders |
Primary outcome
Receipt of the Annual Influenza Vaccine Among Adult and Pediatric Index Patients
Time frame: 6 months
Percent of patients with annual influenza vaccination (between 9/1/22 - 4/1/23) among adult and pediatric index patients. Outcomes will be assessed via vaccine data extraction from the electronic health record and external claims and pharmacy data. The index patients must be an LADHS patient. Primary care patients who are empaneled to a primary care provider within DHS are assigned as follows: (1) assigned through managed care plans, (2) self-pay but linked with a provider or (3) uninsured but assigned). Individuals not affiliated with any primary care practice will be excluded from the primary analysis.
1 secondary outcome
Receipt of the Annual Influenza Vaccine Among Pediatric Index Patients
Time frame: 6 months
Results and safety
Loading the posted results from ClinicalTrials.gov…
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 11 Apr 2025.
- Posted resultsParticipant flow, baseline, all outcome measures and adverse events.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Peter Szilagyi principal investigator
University of California, Los Angeles
2 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Enhanced texts with Callback by a Person and Enhanced Bidirectional Texts in people with Influenza and Respiratory Tract Infections, run by University of California, Los Angeles at 2 sites in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 1 inclusion and 1 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 11 Apr 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 2 sites in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
Yes. Results are posted in the registry (first posted 11 Apr 2025). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Receipt of the Annual Influenza Vaccine Among Adult and Pediatric Index Patients (time frame: 6 months). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 11 Apr 2025.