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Trial End Date February 11, 2022 May 01, 2022
Last Published January 28, 2022 11:01 AM February 16, 2022 03:15 PM
Intervention End Date February 11, 2022 March 01, 2022
Planned Number of Clusters 4000 subjects 4000 subjects (Update for February 16th): 3000 additional subjects who have not previously participated.
Planned Number of Observations 4000 subjects in the main survey + 4000 subjects in a follow-up survey. All 4000 will be included in a follow-up survey, but we anticipate some attrition, so the total number of observations will likely be short of 8000. 4000 subjects in the initial main survey + 4000 subjects in a follow-up to the initial survey. All 4000 will be included in a follow-up survey, but we anticipate some attrition, so the total number of observations will likely be short of 8000. (Update for February 16th): We will be conducting an additional survey to better identify effects of certain interventions. This will involve an additional 3000 subjects who have not previously participated.
Sample size (or number of clusters) by treatment arms Video Treatments: 1. Video Control Condition (VC )(N ≈ 1333): 2. Video Optional Condition (V1)(N ≈ 1333): 3. Video Required Condition (V2)(N ≈ 1333): Paradox treatments: 1. Paradox Control Condition (PC )(N ≈ 1000): 2. Live Virus Paradox (PLV )(N ≈ 1000): 3. Long-Run Paradox (PLR)(N ≈ 1000): 4. Both Paradoxes (PB)(N ≈ 1000): So, each cross-randomization cell should have a sample of approximately 333 subjects. Motivated reasoning randomization: 1. GENERAL (N ≈ 1333) 2. MYOCARDITIS (N ≈ 1333) 3. THROMBOSIS (N ≈ 1333) So, the full 3X4X3 factorial design should have approximately 111 subjects in each cell. However, the even cross-randomization will allow us to identify average treatment effects for each treatment without being restricted to such small samples. Video Treatments: 1. Video Control Condition (VC )(N ≈ 1333): 2. Video Optional Condition (V1)(N ≈ 1333): 3. Video Required Condition (V2)(N ≈ 1333): Paradox treatments: 1. Paradox Control Condition (PC )(N ≈ 1000): 2. Live Virus Paradox (PLV )(N ≈ 1000): 3. Long-Run Paradox (PLR)(N ≈ 1000): 4. Both Paradoxes (PB)(N ≈ 1000): So, each cross-randomization cell should have a sample of approximately 333 subjects. Motivated reasoning randomization: 1. GENERAL (N ≈ 1333) 2. MYOCARDITIS (N ≈ 1333) 3. THROMBOSIS (N ≈ 1333) So, the full 3X4X3 factorial design should have approximately 111 subjects in each cell. However, the even cross-randomization will allow us to identify average treatment effects for each treatment without being restricted to such small samples. (Update for February 16th): In our additional survey, we will simplify the design to better understand the additivity of interventions. These 3000 additional subjects will be assigned using a 2x2 randomization. Paradox treatment random assignment: 1. Paradox Control Condition (PC ) (N ≈ 1500) 2. Both Paradoxes (PB) (N ≈ 1500) Video treatment independent random assignment: 1. Video Control Condition (VC ) (N ≈ 1500) 2. Video Required (VR) (N ≈ 1500) Thus, each cell of the 2X2 for the additional study will contain approximately 750 subjects.
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