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| Name | Class |
|---|---|
| Facebook, Inc. | OTHER |
| Code3 | INDUSTRY |
| Stanford University | OTHER |
| Harvard University |
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This study will distribute videos of health professionals encouraging Covid-19 vaccination to a large sample of Facebook users, and will test the most effective ways to maximize diffusion of this vaccine-related content to increase vaccination rates. The study sample will be U.S. states where vaccination rates remained low in fall 2021. The experimental design is an RCT with 4 groups, randomized at the county level: 1) a control group which receives no intervention, 2) a treatment group in which Facebook users receive ads which include videos of health professionals telling them to get vaccinated, 3) a treatment group in which Facebook users receive ads which include videos of health professionals encouraging them to help their friends to get vaccinated, and 4) a treatment group in which Facebook users receive ads which include videos of health professionals encouraging them to get their most influential friends to help their friends get vaccinated. In treatments 3 and 4, participants will have the option to sign up to be a "vaccine ambassador," in which case they will get notifications when the study team posts new vaccine-related content, and will receive reminders about encouraging their friends to be vaccinated. The vaccine ambassadors will also be entered into a lottery to win prizes. The study team is building a website to host the videos of health professionals which answer common questions about Covid-19 vaccination. The investigators will measure engagement with the vaccine-related content as well as assess effects on vaccination rates at the county level.
The study will have three treatment arms and a control group. Each of the treatments will be randomized at the county level and will be initiated through a Facebook ad campaign.
Experimental Sample: The experimental sample includes all states where less than 60% of the total population had received a first dose of Covid-19 vaccine by October 21, 2021. There are 1402 counties in the 19 states satisfying those criteria (Alabama, Alaska, Arkansas, Georgia, Idaho, Iowa, Indiana, Louisiana, Michigan, Mississippi, Missouri, Montana, North Dakota, Ohio, Oklahoma, South Carolina, Tennessee, West Virginia, Wyoming). Excluding the five counties with missing data, there are 1,397 counties in the experiment, of which there are 468 counties in the control group, 310 counties in T1 ("direct" messaging) treatment, 309 counties in T2 ("friends" messaging), and 310 counties in T3 ("gossips" messaging).
The following procedures will be used:
Treatment and control status at the county level will be merged with aggregated and de-identified datasets to measure COVID vaccinations, COVID symptoms, and cases, and engagement with the vaccine ambassador content.
The study team will create a series of websites with materials that the vaccine ambassadors can share with friends, family and others in their communities. This same content will be disseminated through sponsored Facebook ads in T1. On the website, the framing of the vaccine-related videos with either a "fact" or "myth" frame will be randomized. The purpose is to study which framing is more effective at engaging users.
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| Label | Type | Description | Intervention Names |
|---|---|---|---|
| Control | No Intervention | No intervention in this arm; the study team will examine publicly available county- and zip code-level outcomes in this group. | |
| Treatment 1: Direct | Experimental | Facebook users in the area receive ads which include videos of health professionals telling them to get vaccinated. The health professionals answer common questions about Covid-19 vaccines (e.g. are they safe / are they free). |
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| Treatment 2: Friends | Experimental | Facebook users in the area receive ads which include videos of health professionals encouraging them to help their friends to get vaccinated. There is also a link in the ad to a website build by the study team. This website hosts videos which answer common questions about vaccination (the same videos which are directly served to Facebook users in Treatment 1). |
|
| Treatment 3: Gossips | Experimental | Facebook users in the area receive ads which include videos of health professionals encouraging them to nominate their most influential friends to help their friends get vaccinated. The difference from Treatment 2 is that the health professionals call on Facebook users to get their most influential friends to do the convincing about the vaccine. There is also a link in the ad to a website built by the study team. This website hosts videos which answer common questions about vaccination (the same videos that are directly served to Facebook users in Treatment 1). |
| Name | Type | Description | Arm Group Labels | Other Names |
|---|---|---|---|---|
| Doctor Videos | Behavioral | Receive ads on Facebook or through our website with videos in which health professionals tell people to get the Covid-19 vaccine. The health professionals answer common questions about the Covid-19 vaccine, such as how mRNA vaccines work, and what types of side effects to expect. |
| Measure | Description | Time Frame |
|---|---|---|
| Changes in County-Level Covid-19 Vaccination Measured by Inverse Hyperbolic Sine | County-level Covid-19 vaccination rates were analysed using publicly available data. The number of new vaccinations in each county was transformed using the inverse hyperbolic sine because the underlying vaccination count data were right-skewed and included zeros. Larger numbers are considered better in the context of the study (more people vaccinated). | During intervention (6 weeks) and after intervention (3 weeks) |
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Inclusion Criteria:
Exclusion Criteria:
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| Name | Affiliation | Role |
|---|---|---|
| Esther Duflo, PhD | Massachusetts Institute of Technology | Principal Investigator |
| Ben Olken, PhD | Massachusetts Institute of Technology | Principal Investigator |
| Abhijit Banerjee, PhD | Massachusetts Institute of Technology | Principal Investigator |
| Marcella Alsan, MD, PhD | Harvard Kennedy School | Principal Investigator |
| Arun Chandrasekhar, PhD | Stanford University | Principal Investigator |
| Emily Breza, PhD | Harvard University | Principal Investigator |
| Paul Goldsmith-Pinkham, PhD | Yale University | Principal Investigator |
| Emily Hoppe, PhD Student | Johns Hopkins School of Nursing | Principal Investigator |
| Pierre-Luc Vautrey, PhD Student | Massachusetts Institute of Technology | Principal Investigator |
| Facility | Status | City | State | ZIP | Country | Contacts |
|---|---|---|---|---|---|---|
| Massachusetts Institute of Technology | Cambridge | Massachusetts | 02139 | United States |
The investigators do not plan to share any individual participant data. The only individual participant data that the study will collect will be contact information through the "vaccine ambassador" program. "Vaccine ambassadors" are adults living in geographic areas assigned to Treatment 2 or Treatment 3 who have signed up on the study website to receive updates and reminders about vaccination-related content. However, the study team does not plan on collecting any information about the behavior of vaccine ambassadors, and so do not plan to share any of their data (which will just consisting of contact information) with other researchers.
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| ID | Title | Description |
|---|---|---|
| FG000 | Control | No intervention in this arm; the study team will examine publicly available county- and zip code-level outcomes in this group. |
| FG001 | Treatment 1: Direct | Facebook users in the area receive ads which include videos of health professionals telling them to get vaccinated. The health professionals answer common questions about Covid-19 vaccines (e.g. are they safe / are they free). Doctor Videos: Receive ads on Facebook or through our website with videos in which health professionals tell people to get the Covid-19 vaccine. The health professionals answer common questions about the Covid-19 vaccine, such as how mRNA vaccines work, and what types of side effects to expect. |
| FG002 | Treatment 2: Friends | Facebook users in the area receive ads which include videos of health professionals encouraging them to help their friends to get vaccinated. There is also a link in the ad to a website build by the study team. This website hosts videos which answer common questions about vaccination (the same videos which are directly served to Facebook users in Treatment 1). Doctor Videos: Receive ads on Facebook or through our website with videos in which health professionals tell people to get the Covid-19 vaccine. The health professionals answer common questions about the Covid-19 vaccine, such as how mRNA vaccines work, and what types of side effects to expect. Sharing Videos: Receive ads on Facebook with videos in which health professionals tell people to encourage their unvaccinated friends to get the Covid-19 vaccine. Vaccine Ambassador: Adults in participating geographic areas can sign up to be a "vaccine ambassador" on a website that the study team has built. Video framing: Visitors to the vaccine content website will randomly receive one framing of each video ("myth" or "fact"). Video order: The order in which videos appear is randomized. |
| FG003 | Treatment 3: Gossips | Facebook users in the area receive ads which include videos of health professionals encouraging them to nominate their most influential friends to help their friends get vaccinated. The difference from Treatment 2 is that the health professionals call on Facebook users to get their most influential friends to do the convincing about the vaccine. There is also a link in the ad to a website built by the study team. This website hosts videos which answer common questions about vaccination (the same videos that are directly served to Facebook users in Treatment 1). Doctor Videos: Receive ads on Facebook or through our website with videos in which health professionals tell people to get the Covid-19 vaccine. The health professionals answer common questions about the Covid-19 vaccine, such as how mRNA vaccines work, and what types of side effects to expect. Sharing Videos (Influencers): Receive ads on Facebook with videos in which health professionals tell people to get their most influential friends to encourage their unvaccinated friends to get the Covid-19 vaccine. Vaccine Ambassador: Adults in participating geographic areas can sign up to be a "vaccine ambassador" on a website that the study team has built. Video framing: Visitors to the vaccine content website will randomly receive one framing of each video ("myth" or "fact"). Video order: The order in which videos appear is randomized. |
| Title | Milestones | Reasons Not Completed | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Overall Study |
|
The analysis used publicly available county-level data, and so the baseline variables all had county-level granularity. We did not collect any person-level baseline measures.
| ID | Title | Description |
|---|---|---|
| BG000 | Control | No intervention in this arm; the study team will examine publicly available county- and zip code-level outcomes in this group. |
| BG001 | Treatment 1: Direct | Facebook users in the area receive ads which include videos of health professionals telling them to get vaccinated. The health professionals answer common questions about Covid-19 vaccines (e.g. are they safe / are they free). Doctor Videos: Receive ads on Facebook or through our website with videos in which health professionals tell people to get the Covid-19 vaccine. The health professionals answer common questions about the Covid-19 vaccine, such as how mRNA vaccines work, and what types of side effects to expect. |
| Units | Counts |
|---|---|
| Participants |
|
| Title | Description | Population Description | Parameter Type | Dispersion Type | Unit of Measure | Calculate Percentage | Denominator Units Selected | Denominators | Classes |
|---|---|---|---|---|---|---|---|---|---|
| Age, Customized | Age data not collected |
| Type | Title | Description | Population Description | Reporting Status | Anticipated Posting Date | Parameter Type | Dispersion Type | Unit of Measure | Calculate Percentage | Time Frame | Units Analyzed | Denominator Units Selected | Arm/Group Information | Denominators | Classes | Analyses | |||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Primary | Changes in County-Level Covid-19 Vaccination Measured by Inverse Hyperbolic Sine | County-level Covid-19 vaccination rates were analysed using publicly available data. The number of new vaccinations in each county was transformed using the inverse hyperbolic sine because the underlying vaccination count data were right-skewed and included zeros. Larger numbers are considered better in the context of the study (more people vaccinated). | Counties were randomized into treatment groups, and outcome data are public county-level data. | Posted | Mean | 95% Confidence Interval | asinh(new dose 1s of vaccine) | During intervention (6 weeks) and after intervention (3 weeks) | Counties | Counties |
|
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As the treatment was a social media campaign administered on Facebook, and individual-level information was not collected for people who simply watched the ads, the study could not monitor for adverse events. "Vaccine ambassadors" were also not monitored for adverse events, as their risk from the study was very small (the only additional interaction between the study and "vaccine ambassadors" was to contact one participant who had won a gift card.)
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| ID | Title | Description | Deaths (Affected) | Deaths (At Risk) | Serious Events (Affected) | Serious Events (At Risk) | Other Events (Affected) | Other Events (At Risk) |
|---|---|---|---|---|---|---|---|---|
| EG000 | Control | No intervention in this arm; the study team will examine publicly available county- and zip code-level outcomes in this group. |
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| Title | Organization | Phone | Extension | |
|---|---|---|---|---|
| LISA HO | MIT | 5106505455 | lisaho@mit.edu |
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| Type | Includes Protocol | Includes SAP | Includes ICF | Document Label | Document Date | Document Uploaded Date | Document File Name |
|---|---|---|---|---|---|---|---|
| Prot_SAP | Yes | Yes | No | Study Protocol and Statistical Analysis Plan | Jan 24, 2022 | Mar 6, 2023 | Prot_SAP_000.pdf |
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| ID | Term |
|---|---|
| D000072758 | Vaccination Refusal |
| D000086382 | COVID-19 |
| ID | Term |
|---|---|
| D016312 | Treatment Refusal |
| D000074822 | Treatment Adherence and Compliance |
| D015438 | Health Behavior |
| D001519 | Behavior |
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| Yale University | OTHER |
| Johns Hopkins University | OTHER |
| Massachusetts General Hospital | OTHER |
| Ludwig-Maximilians - University of Munich | OTHER |
| National Institutes of Health (NIH) | NIH |
There are four arms in the study which geographic areas are assigned to in parallel. The geographic areas in the three treatment arms will receive a Facebook ad campaign over the same time period to one another.
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|
|
| Sharing Videos | Behavioral | Receive ads on Facebook with videos in which health professionals tell people to encourage their unvaccinated friends to get the Covid-19 vaccine. |
|
| Sharing Videos (Influencers) | Behavioral | Receive ads on Facebook with videos in which health professionals tell people to get their most influential friends to encourage their unvaccinated friends to get the Covid-19 vaccine. |
|
| Vaccine Ambassador | Behavioral | Adults in participating geographic areas can sign up to be a "vaccine ambassador" on a website that the study team has built. The study team will send updates to vaccine ambassadors when new content has been posted to the website (e.g. a new video) and/or to remind the vaccine ambassadors to encourage their friends to get vaccinated. The study team will incentivize vaccine ambassadors by entering participating ambassadors into a lottery for a prize. |
|
| Video framing | Behavioral | The same videos will be displayed using two different frames: a "myth" frame and a "fact" frame. Visitors to the vaccine content website will randomly receive one framing of each video. |
|
| Video order | Behavioral | The order in which videos appear on the vaccine content website will be randomized. |
|
| Lisa Ho, PhD Student |
| Massachusetts Institute of Technology |
| Principal Investigator |
| Lucy Ogbu-Nwobodo, MD | MGH/McLean Harvard Psychiatry Program | Principal Investigator |
| Erica Warner, ScD, MPH | Harvard Medical School & Massachusetts General Hospital | Principal Investigator |
| Carlos Torres, MD | Massachusetts General Hospital | Principal Investigator |
| Fatima Stanford, MD, MPH, MPA | Harvard Medical School & Massachusetts General Hospital | Principal Investigator |
| Sarah Eichmeyer, PhD | Ludwig-Maximilians - University of Munich | Principal Investigator |
| BG002 | Treatment 2: Friends | Facebook users in the area receive ads which include videos of health professionals encouraging them to help their friends to get vaccinated. There is also a link in the ad to a website build by the study team. This website hosts videos which answer common questions about vaccination (the same videos which are directly served to Facebook users in Treatment 1). Doctor Videos: Receive ads on Facebook or through our website with videos in which health professionals tell people to get the Covid-19 vaccine. The health professionals answer common questions about the Covid-19 vaccine, such as how mRNA vaccines work, and what types of side effects to expect. Sharing Videos: Receive ads on Facebook with videos in which health professionals tell people to encourage their unvaccinated friends to get the Covid-19 vaccine. Vaccine Ambassador: Adults in participating geographic areas can sign up to be a "vaccine ambassador" on a website that the study team has built. Video framing: Visitors to the vaccine content website will randomly receive one framing of each video ("myth" or "fact"). Video order: The order in which videos appear is randomized. |
| BG003 | Treatment 3: Gossips | Facebook users in the area receive ads which include videos of health professionals encouraging them to nominate their most influential friends to help their friends get vaccinated. The difference from Treatment 2 is that the health professionals call on Facebook users to get their most influential friends to do the convincing about the vaccine. There is also a link in the ad to a website built by the study team. This website hosts videos which answer common questions about vaccination (the same videos that are directly served to Facebook users in Treatment 1). Doctor Videos: Receive ads on Facebook or through our website with videos in which health professionals tell people to get the Covid-19 vaccine. The health professionals answer common questions about the Covid-19 vaccine, such as how mRNA vaccines work, and what types of side effects to expect. Sharing Videos (Influencers): Receive ads on Facebook with videos in which health professionals tell people to get their most influential friends to encourage their unvaccinated friends to get the Covid-19 vaccine. Vaccine Ambassador: Adults in participating geographic areas can sign up to be a "vaccine ambassador" on a website that the study team has built. Video framing: Visitors to the vaccine content website will randomly receive one framing of each video ("myth" or "fact"). Video order: The order in which videos appear is randomized. |
| BG004 | Total | Total of all reporting groups |
| Counties |
|
| participants |
| Counties |
|
|
| Sex/Gender, Customized | Gender data was not collected. All gender data used were publicly available county-level data that was not collected for this experiment. We do not collect individual-level baseline data. | Number | percent | Counties |
|
|
| Ethnicity (NIH/OMB) | Ethnicity data not collected | Ethnicity data not collected | Count of Units | Counties | Counties |
|
|
| Race (NIH/OMB) | Race data not collected | Count of Units | Counties | Counties |
|
|
| OG001 | Treatment 1: Direct | Facebook users in the area receive ads which include videos of health professionals telling them to get vaccinated. The health professionals answer common questions about Covid-19 vaccines (e.g. are they safe / are they free). Doctor Videos: Receive ads on Facebook or through our website with videos in which health professionals tell people to get the Covid-19 vaccine. The health professionals answer common questions about the Covid-19 vaccine, such as how mRNA vaccines work, and what types of side effects to expect. |
| OG002 | Treatment 2: Friends | Facebook users in the area receive ads which include videos of health professionals encouraging them to help their friends to get vaccinated. There is also a link in the ad to a website build by the study team. This website hosts videos which answer common questions about vaccination (the same videos which are directly served to Facebook users in Treatment 1). Doctor Videos: Receive ads on Facebook or through our website with videos in which health professionals tell people to get the Covid-19 vaccine. The health professionals answer common questions about the Covid-19 vaccine, such as how mRNA vaccines work, and what types of side effects to expect. Sharing Videos: Receive ads on Facebook with videos in which health professionals tell people to encourage their unvaccinated friends to get the Covid-19 vaccine. Vaccine Ambassador: Adults in participating geographic areas can sign up to be a "vaccine ambassador" on a website that the study team has built. Video framing: Visitors to the vaccine content website will randomly receive one framing of each video ("myth" or "fact"). Video order: The order in which videos appear is randomized. |
| OG003 | Treatment 3: Gossips | Facebook users in the area receive ads which include videos of health professionals encouraging them to nominate their most influential friends to help their friends get vaccinated. The difference from Treatment 2 is that the health professionals call on Facebook users to get their most influential friends to do the convincing about the vaccine. There is also a link in the ad to a website built by the study team. This website hosts videos which answer common questions about vaccination (the same videos that are directly served to Facebook users in Treatment 1). Doctor Videos: Receive ads on Facebook or through our website with videos in which health professionals tell people to get the Covid-19 vaccine. The health professionals answer common questions about the Covid-19 vaccine, such as how mRNA vaccines work, and what types of side effects to expect. Sharing Videos (Influencers): Receive ads on Facebook with videos in which health professionals tell people to get their most influential friends to encourage their unvaccinated friends to get the Covid-19 vaccine. Vaccine Ambassador: Adults in participating geographic areas can sign up to be a "vaccine ambassador" on a website that the study team has built. Video framing: Visitors to the vaccine content website will randomly receive one framing of each video ("myth" or "fact"). Video order: The order in which videos appear is randomized. |
|
|
| 0 |
| 0 |
| 0 |
| 0 |
| 0 |
| 0 |
| EG001 | Treatment 1: Direct | Facebook users in the area receive ads which include videos of health professionals telling them to get vaccinated. The health professionals answer common questions about Covid-19 vaccines (e.g. are they safe / are they free). Doctor Videos: Receive ads on Facebook or through our website with videos in which health professionals tell people to get the Covid-19 vaccine. The health professionals answer common questions about the Covid-19 vaccine, such as how mRNA vaccines work, and what types of side effects to expect. | 0 | 0 | 0 | 0 | 0 | 0 |
| EG002 | Treatment 2: Friends | Facebook users in the area receive ads which include videos of health professionals encouraging them to help their friends to get vaccinated. There is also a link in the ad to a website build by the study team. This website hosts videos which answer common questions about vaccination (the same videos which are directly served to Facebook users in Treatment 1). Doctor Videos: Receive ads on Facebook or through our website with videos in which health professionals tell people to get the Covid-19 vaccine. The health professionals answer common questions about the Covid-19 vaccine, such as how mRNA vaccines work, and what types of side effects to expect. Sharing Videos: Receive ads on Facebook with videos in which health professionals tell people to encourage their unvaccinated friends to get the Covid-19 vaccine. Vaccine Ambassador: Adults in participating geographic areas can sign up to be a "vaccine ambassador" on a website that the study team has built. Video framing: Visitors to the vaccine content website will randomly receive one framing of each video ("myth" or "fact"). Video order: The order in which videos appear is randomized. | 0 | 0 | 0 | 0 | 0 | 0 |
| EG003 | Treatment 3: Gossips | Facebook users in the area receive ads which include videos of health professionals encouraging them to nominate their most influential friends to help their friends get vaccinated. The difference from Treatment 2 is that the health professionals call on Facebook users to get their most influential friends to do the convincing about the vaccine. There is also a link in the ad to a website built by the study team. This website hosts videos which answer common questions about vaccination (the same videos that are directly served to Facebook users in Treatment 1). Doctor Videos: Receive ads on Facebook or through our website with videos in which health professionals tell people to get the Covid-19 vaccine. The health professionals answer common questions about the Covid-19 vaccine, such as how mRNA vaccines work, and what types of side effects to expect. Sharing Videos (Influencers): Receive ads on Facebook with videos in which health professionals tell people to get their most influential friends to encourage their unvaccinated friends to get the Covid-19 vaccine. Vaccine Ambassador: Adults in participating geographic areas can sign up to be a "vaccine ambassador" on a website that the study team has built. Video framing: Visitors to the vaccine content website will randomly receive one framing of each video ("myth" or "fact"). Video order: The order in which videos appear is randomized. | 0 | 0 | 0 | 0 | 0 | 0 |
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| D011024 |
| Pneumonia, Viral |
| D011014 | Pneumonia |
| D012141 | Respiratory Tract Infections |
| D007239 | Infections |
| D014777 | Virus Diseases |
| D018352 | Coronavirus Infections |
| D003333 | Coronaviridae Infections |
| D030341 | Nidovirales Infections |
| D012327 | RNA Virus Infections |
| D008171 | Lung Diseases |
| D012140 | Respiratory Tract Diseases |
| Black or African American |
|
| White |
|
| More than one race |
|
| Unknown or Not Reported |
|