Health Behavior, Health Promotion, Influenza, Risk Reduction, Vaccination
Conditions
Keywords
Flu Vaccine, Choice Architecture, Machine Learning, Perceived Credibility, Personalized Risk Factors, Flu Complications
Brief summary
The study team previously demonstrated that patients are more likely to receive flu vaccine after learning that they are at high risk for flu complications. Building on this past work, the present study will explore whether providing reasons that patients are considered high risk for flu complications (a) further increases the likelihood they will receive flu vaccine and (b) decreases the likelihood that they receive diagnoses of flu and/or flu-like symptoms in the ensuing flu season. It will also examine whether informing patients that their high-risk status was determined by analyzing their medical records or by an artificial intelligence (AI) / machine-learning (ML) algorithm analyzing their medical records will affect the likelihood of receiving the flu vaccine or diagnoses of flu and/or flu-like symptoms.
Detailed description
Geisinger has partnered with Medial EarlySign and developed an ML algorithm to identify patients at risk for serious (moderate to severe) flu-associated complications on the basis of their existing electronic health record (EHR) data. Geisinger will apply this algorithm to current patients during the 2021-22 flu season. This study will evaluate the effect of contacting patients identified as high risk with special messages to encourage vaccination. These communications will inform patients they are at high risk with either (a) no additional explanation, (b) an explanation that this determination comes from an analysis of their medical records, along with a short list of the top factors from their medical record that explain their risk, and (c) the additional explanation that an AI or ML algorithm made this determination, along with a short list of the top factors from their medical record that explain their risk. Included in the study will be current Geisinger patients 18+ years of age with no contraindications for flu vaccine and who have been assessed by the Medial algorithm and assigned a risk score. The primary study outcomes will be the rates of flu vaccination and flu diagnosis during the 2020-21 season by targeted patients.
Interventions
BEHAVIORALReminder
Mailed letter, short message service (SMS) text, and/or patient portal message
BEHAVIORALRisk reduction
Mailed letter, SMS, and/or patient portal message
BEHAVIORALMedical records-based recommendation
Mailed letter, SMS, and/or patient portal message
BEHAVIORALAlgorithm-based recommendation
Mailed letter, SMS, and/or patient portal message
Sponsors
Geisinger Clinic
Massachusetts Institute of Technology
National Institute on Aging (NIA)
National Bureau of Economic Research, Inc.
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
PREVENTION
Masking
SINGLE (Caregiver)
Masking description
Providers who prescribe vaccination and diagnose conditions will not be randomized to study arms or informed of patient assignment. Although patients will not be explicitly informed which arm they have been randomized to, they will be aware of the messages they receive.
Intervention model description
Patients from the high-risk sample will be randomly assigned to one of five arms: * No-Contact Control Arm * Reminder Control Arm * High Risk Only Arm * High Risk with Explanation Based on Medical Records Arm * High Risk with Explanation Based on Algorithm Arm
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No
Inclusion criteria
* Aged 18 or older * Current Geisinger patient at the time of study * Falls in the top 10% of patients at highest risk, as identified by the flu-complication risk scores of machine learning algorithm (which operates on coded EHR data)
Exclusion criteria
* Has contraindications for flu vaccination * Has opted out of receiving communications from Geisinger via all of the modalities being tested
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Flu Vaccination at 2 Weeks After Final Outreach Date | Within 2 weeks of the final outreach date, 57 days (8.14 weeks) after the study start | Received flu vaccination |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Flu Diagnosis | 8 months (between September 9, 2021 and April 30, 2022) | Received a high confidence flu diagnosis (with positive polymerase chain reaction \[PCR\]/antigen/molecular test) and/or likely flu diagnosis (as assessed via International Classification of Disease \[ICD\] codes or Tamiflu administration or positive PCR/antigen/molecular test) Note that likely flu is a superset of the high confidence flu diagnoses. |
| Flu Vaccination at 9 Weeks After Final Outreach Date | Within 9 weeks of the final outreach date, 106 days (15.14 weeks) after the study start | Received a flu vaccination |
| Flu Complications | 11 months (between September 9, 2021 and July 31, 2022) | Diagnosed with flu-related complications |
| Healthcare Utilization | 11 months (between September 9, 2021 and July 31, 2022) | Visited ER or was hospitalized NOTE: Our prespecified outcome was description was Visited ER, was hospitalized, or had flu-related insurance claims. We did not receive claims data, so this outcomes includes only ER visits and hospitalizations. |
Other
| Measure | Time frame | Description |
|---|---|---|
| Flu Vaccination at 2 Weeks After Final Outreach Date by Race | Within 2 weeks of the final outreach date, 57 days (8.14 weeks) after the study start | Received Flu Vaccination |
| Flu Vaccination at 2 Weeks After Final Outreach Date by Gender | Within 2 weeks of the final outreach date, 57 days (8.14 weeks) after the study start | Received a flu vaccination |
| Flu Vaccination at 2 Weeks After Final Outreach Date by Ethnicity | Within 2 weeks of the final outreach date, 57 days (8.14 weeks) after the study start | Received flu vaccination |
Countries
United States
Participant flow
Participants by arm
| Arm | Count |
|---|---|
| No-Contact Control Subjects in the no-contact control arm will receive no additional pro-vaccination intervention beyond the health system's normal efforts. Although some patients are currently targeted for flu vaccination encouragement due to a conventional non-ML assessment that they are at high risk for complications, these patients are not told that they are at high risk or that they have been targeted. | 9,017 |
| Reminder Control Subjects in the reminder control arm will receive messages reminding them to get the flu shot without being advised of their risk status.
Reminder: Mailed letter, short message service (SMS) text, and/or patient portal message | 9,013 |
| High Risk Only Subjects in this treatment arm will receive messages telling them they have been identified to be at high risk for flu complications, without specifying how or why the health system believes this to be the case.
Reminder: Mailed letter, short message service (SMS) text, and/or patient portal message
Risk reduction: Mailed letter, SMS, and/or patient portal message | 9,011 |
| High Risk With Explanation Based on Medical Records Subjects in this treatment arm will receive messages telling them they have been identified to be at high risk for flu complications via review of their medical records and will be provided a human-understandable short list of the top factors from their medical record that explain their risk.
Reminder: Mailed letter, short message service (SMS) text, and/or patient portal message
Risk reduction: Mailed letter, SMS, and/or patient portal message
Medical records-based recommendation: Mailed letter, SMS, and/or patient portal message | 9,003 |
| High Risk With Explanation Based on Algorithm Subjects in this treatment arm will receive messages telling them they have been identified to be at high risk for flu complications via analysis of their medical records by a computer algorithm and will be provided a human-understandable short list of the top factors from their medical record that explain their risk.
Reminder: Mailed letter, short message service (SMS) text, and/or patient portal message
Risk reduction: Mailed letter, SMS, and/or patient portal message
Medical records-based recommendation: Mailed letter, SMS, and/or patient portal message
Algorithm-based recommendation: Mailed letter, SMS, and/or patient portal message | 9,017 |
| Total | 45,061 |
Withdrawals & dropouts
| Period | Reason | FG000 | FG001 | FG002 | FG003 | FG004 |
|---|---|---|---|---|---|---|
| Overall Study | Death | 25 | 22 | 24 | 19 | 15 |
| Overall Study | Protocol Violation | 100 | 105 | 119 | 120 | 119 |
Baseline characteristics
| Characteristic | No-Contact Control | High Risk Only | Reminder Control | High Risk With Explanation Based on Medical Records | High Risk With Explanation Based on Algorithm | Total |
|---|---|---|---|---|---|---|
| Age, Customized >=18 years and <65 | 6018 Participants | 6049 Participants | 5984 Participants | 6001 Participants | 6004 Participants | 30056 Participants |
| Age, Customized >=65 | 2999 Participants | 2962 Participants | 3029 Participants | 3002 Participants | 3013 Participants | 15005 Participants |
| Ethnicity (NIH/OMB) Hispanic or Latino | 381 Participants | 374 Participants | 351 Participants | 353 Participants | 365 Participants | 1824 Participants |
| Ethnicity (NIH/OMB) Not Hispanic or Latino | 8608 Participants | 8607 Participants | 8635 Participants | 8627 Participants | 8630 Participants | 43107 Participants |
| Ethnicity (NIH/OMB) Unknown or Not Reported | 28 Participants | 30 Participants | 27 Participants | 23 Participants | 22 Participants | 130 Participants |
| Race/Ethnicity, Customized American Indian or Alaska Native | 11 Participants | 14 Participants | 19 Participants | 16 Participants | 16 Participants | 76 Participants |
| Race/Ethnicity, Customized Asian | 27 Participants | 23 Participants | 21 Participants | 26 Participants | 27 Participants | 124 Participants |
| Race/Ethnicity, Customized Black or African American | 348 Participants | 300 Participants | 286 Participants | 330 Participants | 300 Participants | 1564 Participants |
| Race/Ethnicity, Customized Native Hawaiian or Other Pacific Islander | 15 Participants | 12 Participants | 12 Participants | 16 Participants | 20 Participants | 75 Participants |
| Race/Ethnicity, Customized Unknown or Not Reported | 20 Participants | 14 Participants | 15 Participants | 13 Participants | 18 Participants | 80 Participants |
| Race/Ethnicity, Customized White | 8596 Participants | 8648 Participants | 8660 Participants | 8602 Participants | 8636 Participants | 43142 Participants |
| Sex: Female, Male Female | 6038 Participants | 6107 Participants | 6121 Participants | 6086 Participants | 6140 Participants | 30492 Participants |
| Sex: Female, Male Male | 2979 Participants | 2904 Participants | 2892 Participants | 2917 Participants | 2877 Participants | 14569 Participants |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk | EG002 affected / at risk | EG003 affected / at risk | EG004 affected / at risk |
|---|---|---|---|---|---|
| deaths Total, all-cause mortality | 25 / 9,017 | 22 / 9,013 | 24 / 9,011 | 19 / 9,003 | 17 / 9,017 |
| other Total, other adverse events | 0 / 0 | 0 / 0 | 0 / 0 | 0 / 0 | 0 / 0 |
| serious Total, serious adverse events | 0 / 0 | 0 / 0 | 0 / 0 | 0 / 0 | 0 / 0 |
Outcome results
Primary
Flu Vaccination at 2 Weeks After Final Outreach Date
Received flu vaccination
Time frame: Within 2 weeks of the final outreach date, 57 days (8.14 weeks) after the study start
Population: Patients were excluded from analyses if they died before or during the study, if they were contraindicated for flu vaccine, if they were sent protective risk reasons, or if they were vaccinated prior to the study beginning. See the Statistical Analysis Plan for more information on exclusions.
| Arm | Measure | Category | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|---|
| No-Contact Control | Flu Vaccination at 2 Weeks After Final Outreach Date | Not Vaccinated | 5798 Participants |
| No-Contact Control | Flu Vaccination at 2 Weeks After Final Outreach Date | Vaccinated | 2668 Participants |
| Reminder Control | Flu Vaccination at 2 Weeks After Final Outreach Date | Not Vaccinated | 5715 Participants |
| Reminder Control | Flu Vaccination at 2 Weeks After Final Outreach Date | Vaccinated | 2807 Participants |
| High Risk Only | Flu Vaccination at 2 Weeks After Final Outreach Date | Not Vaccinated | 5560 Participants |
| High Risk Only | Flu Vaccination at 2 Weeks After Final Outreach Date | Vaccinated | 2938 Participants |
| High Risk With Explanation Based on Medical Records | Flu Vaccination at 2 Weeks After Final Outreach Date | Vaccinated | 2887 Participants |
| High Risk With Explanation Based on Medical Records | Flu Vaccination at 2 Weeks After Final Outreach Date | Not Vaccinated | 5583 Participants |
| High Risk With Explanation Based on Algorithm | Flu Vaccination at 2 Weeks After Final Outreach Date | Not Vaccinated | 5662 Participants |
| High Risk With Explanation Based on Algorithm | Flu Vaccination at 2 Weeks After Final Outreach Date | Vaccinated | 2863 Participants |
Comparison: This analysis compared groups that were informed they were high risk (High Risk Only, High Risk Based on Medical Records, High Risk Based on Algorithm) to Reminder Control patients who were sent messages that did not disclose their risk status. Null hypothesis: messages that inform patients they are high risk do not increase flu vaccination rate vs. messages that do not disclose risk status; Alternative hypothesis: messages that inform patients they are high risk increase flu vaccination rate.p-value: 0.054Regression, Linear
Comparison: This analysis compared groups that were informed they were high risk (High Risk Only, High Risk Based on Medical Records, High Risk Based on Algorithm) to No-Contact Control patients who were not sent messages. Null hypothesis: messages that inform patients they are high risk do not increase flu vaccination rate relative to no messages; Alternative hypothesis: messages that inform patients they are high risk increase flu vaccination rate.p-value: <0.001Regression, Linear
Comparison: This analysis compared groups who received messages including risk reasons (High Risk Based on Medical Records, High Risk Based on Algorithm) to messages that mentioned patients' risk status but do not include reasons (High Risk Only). Null hypothesis: messages that include risk reasons do not increase flu vaccination rate relative to high-risk messages that do not include risk reasons; Alternative hypothesis: messages including risk reasons are more effective at increasing vaccination rates.p-value: 0.24Regression, Linear
Comparison: Null hypothesis: flu-shot messages that do not mention high-risk status do not increase vaccination relative to no messages; Alternative hypothesis: flu shot messages that do not mention high-risk status increase flu shots relative to no messages.p-value: 0.047Regression, Linear
Comparison: Null hypothesis: High Risk Only and High Risk Based on Medical Records messages are equally effective at promoting flu vaccinations; Alternative hypothesis: there is a difference in effectiveness between High Risk Only and High Risk Based on Medical Records.p-value: 0.781Regression, Linear
Comparison: Null hypothesis: High Risk Only and High Risk Based on Algorithm messages are equally effective at promoting flu vaccinations; Alternative hypothesis: there is a difference in effectiveness between High Risk Only and High Risk Based on Algorithm.p-value: 0.361Regression, Linear
Comparison: Null hypothesis: High Risk Based on Medical Records and High Risk Based on Algorithm messages are equally effective at promoting flu vaccinations; Alternative hypothesis: there is a difference in effectiveness between High Risk Based on Medical Records and High Risk Based on Algorithm.p-value: 0.77Regression, Linear
Secondary
Flu Complications
Diagnosed with flu-related complications
Time frame: 11 months (between September 9, 2021 and July 31, 2022)
| Arm | Measure | Category | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|---|
| No-Contact Control | Flu Complications | No flu complications | 5916 Participants |
| No-Contact Control | Flu Complications | Flu complications | 2550 Participants |
| Reminder Control | Flu Complications | No flu complications | 5904 Participants |
| Reminder Control | Flu Complications | Flu complications | 2618 Participants |
| High Risk Only | Flu Complications | No flu complications | 5910 Participants |
| High Risk Only | Flu Complications | Flu complications | 2588 Participants |
| High Risk With Explanation Based on Medical Records | Flu Complications | Flu complications | 2609 Participants |
| High Risk With Explanation Based on Medical Records | Flu Complications | No flu complications | 5861 Participants |
| High Risk With Explanation Based on Algorithm | Flu Complications | No flu complications | 5853 Participants |
| High Risk With Explanation Based on Algorithm | Flu Complications | Flu complications | 2672 Participants |
Secondary
Flu Diagnosis
Received a high confidence flu diagnosis (with positive polymerase chain reaction \[PCR\]/antigen/molecular test) and/or likely flu diagnosis (as assessed via International Classification of Disease \[ICD\] codes or Tamiflu administration or positive PCR/antigen/molecular test) Note that likely flu is a superset of the high confidence flu diagnoses.
Time frame: 8 months (between September 9, 2021 and April 30, 2022)
| Arm | Measure | Group | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|---|
| No-Contact Control | Flu Diagnosis | No flu diagnosis | 8336 Participants |
| No-Contact Control | Flu Diagnosis | Flu diagnosis | 130 Participants |
| Reminder Control | Flu Diagnosis | No flu diagnosis | 8382 Participants |
| Reminder Control | Flu Diagnosis | Flu diagnosis | 140 Participants |
| High Risk Only | Flu Diagnosis | No flu diagnosis | 8365 Participants |
| High Risk Only | Flu Diagnosis | Flu diagnosis | 133 Participants |
| High Risk With Explanation Based on Medical Records | Flu Diagnosis | Flu diagnosis | 124 Participants |
| High Risk With Explanation Based on Medical Records | Flu Diagnosis | No flu diagnosis | 8346 Participants |
| High Risk With Explanation Based on Algorithm | Flu Diagnosis | No flu diagnosis | 8385 Participants |
| High Risk With Explanation Based on Algorithm | Flu Diagnosis | Flu diagnosis | 140 Participants |
Secondary
Flu Vaccination at 9 Weeks After Final Outreach Date
Received a flu vaccination
Time frame: Within 9 weeks of the final outreach date, 106 days (15.14 weeks) after the study start
| Arm | Measure | Category | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|---|
| No-Contact Control | Flu Vaccination at 9 Weeks After Final Outreach Date | Not Vaccinated | 5180 Participants |
| No-Contact Control | Flu Vaccination at 9 Weeks After Final Outreach Date | Vaccinated | 3286 Participants |
| Reminder Control | Flu Vaccination at 9 Weeks After Final Outreach Date | Not Vaccinated | 5093 Participants |
| Reminder Control | Flu Vaccination at 9 Weeks After Final Outreach Date | Vaccinated | 3429 Participants |
| High Risk Only | Flu Vaccination at 9 Weeks After Final Outreach Date | Not Vaccinated | 4973 Participants |
| High Risk Only | Flu Vaccination at 9 Weeks After Final Outreach Date | Vaccinated | 3525 Participants |
| High Risk With Explanation Based on Medical Records | Flu Vaccination at 9 Weeks After Final Outreach Date | Vaccinated | 3535 Participants |
| High Risk With Explanation Based on Medical Records | Flu Vaccination at 9 Weeks After Final Outreach Date | Not Vaccinated | 4935 Participants |
| High Risk With Explanation Based on Algorithm | Flu Vaccination at 9 Weeks After Final Outreach Date | Not Vaccinated | 5076 Participants |
| High Risk With Explanation Based on Algorithm | Flu Vaccination at 9 Weeks After Final Outreach Date | Vaccinated | 3449 Participants |
Secondary
Healthcare Utilization
Visited ER or was hospitalized NOTE: Our prespecified outcome was description was Visited ER, was hospitalized, or had flu-related insurance claims. We did not receive claims data, so this outcomes includes only ER visits and hospitalizations.
Time frame: 11 months (between September 9, 2021 and July 31, 2022)
| Arm | Measure | Category | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|---|
| No-Contact Control | Healthcare Utilization | No utilization | 5203 Participants |
| No-Contact Control | Healthcare Utilization | Utilization | 3263 Participants |
| Reminder Control | Healthcare Utilization | No utilization | 5221 Participants |
| Reminder Control | Healthcare Utilization | Utilization | 3301 Participants |
| High Risk Only | Healthcare Utilization | No utilization | 5205 Participants |
| High Risk Only | Healthcare Utilization | Utilization | 3293 Participants |
| High Risk With Explanation Based on Medical Records | Healthcare Utilization | Utilization | 3310 Participants |
| High Risk With Explanation Based on Medical Records | Healthcare Utilization | No utilization | 5160 Participants |
| High Risk With Explanation Based on Algorithm | Healthcare Utilization | No utilization | 5311 Participants |
| High Risk With Explanation Based on Algorithm | Healthcare Utilization | Utilization | 3214 Participants |
Other Pre-specified
Flu Vaccination at 2 Weeks After Final Outreach Date by Ethnicity
Received flu vaccination
Time frame: Within 2 weeks of the final outreach date, 57 days (8.14 weeks) after the study start
Population: Patients were excluded from analyses if they died before or during the study, if they were contraindicated for flu vaccine, if they were sent protective risk reasons, or if they were vaccinated prior to the study beginning. See the Statistical Analysis Plan for more information on exclusions.
| Arm | Measure | Group | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|---|
| No-Contact Control | Flu Vaccination at 2 Weeks After Final Outreach Date by Ethnicity | Hispanic or Latino | 76 Participants |
| No-Contact Control | Flu Vaccination at 2 Weeks After Final Outreach Date by Ethnicity | Unable to Obtain | 14 Participants |
| No-Contact Control | Flu Vaccination at 2 Weeks After Final Outreach Date by Ethnicity | Not Hispanic or Latino | 2578 Participants |
| Reminder Control | Flu Vaccination at 2 Weeks After Final Outreach Date by Ethnicity | Not Hispanic or Latino | 2722 Participants |
| Reminder Control | Flu Vaccination at 2 Weeks After Final Outreach Date by Ethnicity | Hispanic or Latino | 76 Participants |
| Reminder Control | Flu Vaccination at 2 Weeks After Final Outreach Date by Ethnicity | Unable to Obtain | 9 Participants |
| High Risk Only | Flu Vaccination at 2 Weeks After Final Outreach Date by Ethnicity | Not Hispanic or Latino | 2865 Participants |
| High Risk Only | Flu Vaccination at 2 Weeks After Final Outreach Date by Ethnicity | Hispanic or Latino | 68 Participants |
| High Risk Only | Flu Vaccination at 2 Weeks After Final Outreach Date by Ethnicity | Unable to Obtain | 5 Participants |
| High Risk With Explanation Based on Medical Records | Flu Vaccination at 2 Weeks After Final Outreach Date by Ethnicity | Hispanic or Latino | 78 Participants |
| High Risk With Explanation Based on Medical Records | Flu Vaccination at 2 Weeks After Final Outreach Date by Ethnicity | Unable to Obtain | 5 Participants |
| High Risk With Explanation Based on Medical Records | Flu Vaccination at 2 Weeks After Final Outreach Date by Ethnicity | Not Hispanic or Latino | 2804 Participants |
| High Risk With Explanation Based on Algorithm | Flu Vaccination at 2 Weeks After Final Outreach Date by Ethnicity | Not Hispanic or Latino | 2784 Participants |
| High Risk With Explanation Based on Algorithm | Flu Vaccination at 2 Weeks After Final Outreach Date by Ethnicity | Hispanic or Latino | 71 Participants |
| High Risk With Explanation Based on Algorithm | Flu Vaccination at 2 Weeks After Final Outreach Date by Ethnicity | Unable to Obtain | 8 Participants |
Other Pre-specified
Flu Vaccination at 2 Weeks After Final Outreach Date by Gender
Received a flu vaccination
Time frame: Within 2 weeks of the final outreach date, 57 days (8.14 weeks) after the study start
Population: Patients were excluded from analyses if they died before or during the study, if they were contraindicated for flu vaccine, if they were sent protective risk reasons, or if they were vaccinated prior to the study beginning. See the Statistical Analysis Plan for more information on exclusions.
| Arm | Measure | Group | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|---|
| No-Contact Control | Flu Vaccination at 2 Weeks After Final Outreach Date by Gender | Male | 928 Participants |
| No-Contact Control | Flu Vaccination at 2 Weeks After Final Outreach Date by Gender | Female | 1740 Participants |
| Reminder Control | Flu Vaccination at 2 Weeks After Final Outreach Date by Gender | Female | 1840 Participants |
| Reminder Control | Flu Vaccination at 2 Weeks After Final Outreach Date by Gender | Male | 967 Participants |
| High Risk Only | Flu Vaccination at 2 Weeks After Final Outreach Date by Gender | Male | 1005 Participants |
| High Risk Only | Flu Vaccination at 2 Weeks After Final Outreach Date by Gender | Female | 1933 Participants |
| High Risk With Explanation Based on Medical Records | Flu Vaccination at 2 Weeks After Final Outreach Date by Gender | Female | 1878 Participants |
| High Risk With Explanation Based on Medical Records | Flu Vaccination at 2 Weeks After Final Outreach Date by Gender | Male | 1009 Participants |
| High Risk With Explanation Based on Algorithm | Flu Vaccination at 2 Weeks After Final Outreach Date by Gender | Male | 930 Participants |
| High Risk With Explanation Based on Algorithm | Flu Vaccination at 2 Weeks After Final Outreach Date by Gender | Female | 1933 Participants |
Other Pre-specified
Flu Vaccination at 2 Weeks After Final Outreach Date by Race
Received Flu Vaccination
Time frame: Within 2 weeks of the final outreach date, 57 days (8.14 weeks) after the study start
Population: Patients were excluded from analyses if they died before or during the study, if they were contraindicated for flu vaccine, if they were sent protective risk reasons, or if they were vaccinated prior to the study beginning. See the Statistical Analysis Plan for more information on exclusions.
| Arm | Measure | Group | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|---|
| No-Contact Control | Flu Vaccination at 2 Weeks After Final Outreach Date by Race | American Indian or Alaska Native | 2 Participants |
| No-Contact Control | Flu Vaccination at 2 Weeks After Final Outreach Date by Race | Asian | 8 Participants |
| No-Contact Control | Flu Vaccination at 2 Weeks After Final Outreach Date by Race | Black | 67 Participants |
| No-Contact Control | Flu Vaccination at 2 Weeks After Final Outreach Date by Race | Native Hawaiian or Other Pacific Islander | 4 Participants |
| No-Contact Control | Flu Vaccination at 2 Weeks After Final Outreach Date by Race | Unknown | 1 Participants |
| No-Contact Control | Flu Vaccination at 2 Weeks After Final Outreach Date by Race | White | 2586 Participants |
| Reminder Control | Flu Vaccination at 2 Weeks After Final Outreach Date by Race | Unknown | 5 Participants |
| Reminder Control | Flu Vaccination at 2 Weeks After Final Outreach Date by Race | White | 2742 Participants |
| Reminder Control | Flu Vaccination at 2 Weeks After Final Outreach Date by Race | American Indian or Alaska Native | 3 Participants |
| Reminder Control | Flu Vaccination at 2 Weeks After Final Outreach Date by Race | Black | 51 Participants |
| Reminder Control | Flu Vaccination at 2 Weeks After Final Outreach Date by Race | Native Hawaiian or Other Pacific Islander | 1 Participants |
| Reminder Control | Flu Vaccination at 2 Weeks After Final Outreach Date by Race | Asian | 5 Participants |
| High Risk Only | Flu Vaccination at 2 Weeks After Final Outreach Date by Race | Native Hawaiian or Other Pacific Islander | 1 Participants |
| High Risk Only | Flu Vaccination at 2 Weeks After Final Outreach Date by Race | Unknown | 4 Participants |
| High Risk Only | Flu Vaccination at 2 Weeks After Final Outreach Date by Race | American Indian or Alaska Native | 1 Participants |
| High Risk Only | Flu Vaccination at 2 Weeks After Final Outreach Date by Race | Black | 68 Participants |
| High Risk Only | Flu Vaccination at 2 Weeks After Final Outreach Date by Race | Asian | 7 Participants |
| High Risk Only | Flu Vaccination at 2 Weeks After Final Outreach Date by Race | White | 2857 Participants |
| High Risk With Explanation Based on Medical Records | Flu Vaccination at 2 Weeks After Final Outreach Date by Race | Native Hawaiian or Other Pacific Islander | 6 Participants |
| High Risk With Explanation Based on Medical Records | Flu Vaccination at 2 Weeks After Final Outreach Date by Race | Asian | 12 Participants |
| High Risk With Explanation Based on Medical Records | Flu Vaccination at 2 Weeks After Final Outreach Date by Race | Black | 61 Participants |
| High Risk With Explanation Based on Medical Records | Flu Vaccination at 2 Weeks After Final Outreach Date by Race | White | 2801 Participants |
| High Risk With Explanation Based on Medical Records | Flu Vaccination at 2 Weeks After Final Outreach Date by Race | Unknown | 5 Participants |
| High Risk With Explanation Based on Medical Records | Flu Vaccination at 2 Weeks After Final Outreach Date by Race | American Indian or Alaska Native | 2 Participants |
| High Risk With Explanation Based on Algorithm | Flu Vaccination at 2 Weeks After Final Outreach Date by Race | Unknown | 1 Participants |
| High Risk With Explanation Based on Algorithm | Flu Vaccination at 2 Weeks After Final Outreach Date by Race | Black | 49 Participants |
| High Risk With Explanation Based on Algorithm | Flu Vaccination at 2 Weeks After Final Outreach Date by Race | Asian | 7 Participants |
| High Risk With Explanation Based on Algorithm | Flu Vaccination at 2 Weeks After Final Outreach Date by Race | White | 2796 Participants |
| High Risk With Explanation Based on Algorithm | Flu Vaccination at 2 Weeks After Final Outreach Date by Race | Native Hawaiian or Other Pacific Islander | 3 Participants |
| High Risk With Explanation Based on Algorithm | Flu Vaccination at 2 Weeks After Final Outreach Date by Race | American Indian or Alaska Native | 7 Participants |