x

NEW UPDATE: Completed trials may now upload and register supplementary documents (e.g. null results reports, populated pre-analysis plans, or post-trial results reports) in the Post Trial section under Reports, Papers, & Other Materials.
Behavioral Response to COVID-19 Antibody Testing
Last registered on July 13, 2020

Pre-Trial

Trial Information
General Information
Title
Behavioral Response to COVID-19 Antibody Testing
RCT ID
AEARCTR-0006119
Initial registration date
July 10, 2020
Last updated
July 13, 2020 3:42 PM EDT
Location(s)
Primary Investigator
Affiliation
USC
Other Primary Investigator(s)
PI Affiliation
UCLA
PI Affiliation
USC
Additional Trial Information
Status
In development
Start date
2020-07-06
End date
2021-02-28
Secondary IDs
Abstract
This study aims to shed light on how people response to COVID-19 antibody testing. In collaboration with Contra Costa County Health Services (CCHS), we will field two nearly identical online surveys designed to capture both individual beliefs about COVID-19 and behavior taken to mitigate the spread of the disease. The surveys will be fielded to asymptomatic people who show up to a phlebotomy clinic for routine clinician-ordered lab tests and are not explicitly coming for COVID-19 testing. By (randomly) offering some people coming in for lab work a free blood antibody test at the same time, we will be able to study not only how testing affects beliefs about exposure as well as preventive behavior. We can also characterize who takes up the offer of the antibody test.
External Link(s)
Registration Citation
Citation
Chang, Tom, Mireille Jacobson and Manisha Shah. 2020. "Behavioral Response to COVID-19 Antibody Testing." AEA RCT Registry. July 13. https://doi.org/10.1257/rct.6119-1.0.
Sponsors & Partners

There are documents in this trial unavailable to the public. Use the button below to request access to this information.

Request Information
Experimental Details
Interventions
Intervention(s)
Randomized offer of a free COVID-19 antibody test to individuals showing up to CCHS for routine blood lab work.
Intervention Start Date
2020-07-06
Intervention End Date
2020-08-14
Primary Outcomes
Primary Outcomes (end points)
Percent chance you had COVID-19; uncertainty about chance you have COVID-19; index of positive preventive health behavior in the past 7 days.
Primary Outcomes (explanation)
Our survey asks individuals the percent chance they have had COVID-19 as well as their confidence in their estimate. It also captures the following behaviors in the past 7 days -- wore a mask; washed hands with soap or used hand sanitizer several times per day; canceled or postponed personal or social activities; avoided eating at restaurants; self-isolating; avoided attending social gatherings; avoided contact with high risk individuals. We will combine these outcomes into an index that is the sum of responses.

We will measure these outcomes at two points in time, first within 24 hours of recruitment and second about 2 weeks later.
Secondary Outcomes
Secondary Outcomes (end points)
Selection into testing among those in the treatment group. Other behaviors in the past 7 days such as whether individuals are stockpiling food, working for pay, exercising, attending religious services, and getting help with domestic chores; media consumption; beliefs about getting COVID-19, about someone the respondent knows getting COVID-19, about someone the respondent’s age dying from COVID-19 if infected and about COVID-19 affecting earnings.
Secondary Outcomes (explanation)
We will study test take-up. Specifically, among those who received a (random) offer for an antibody test, what are the observable characteristics of those who select in to testing. We will also analyze the effect of assignment to testing on changes in the secondary outcomes listed above. We will also analyze the effect of test offer on changes in (1) other behaviors in the past 7 days such as whether individuals are stockpiling food, working for pay, exercising, attending religious services, and getting help with domestic chores; (2) media consumption and (3) beliefs about getting COVID-19, about someone the respondent knows getting COVID-19, about someone the respondent’s age dying from COVID-19 if infected and about COVID-19 affecting earnings.
Experimental Design
Experimental Design
Individuals will be randomized based on clinic x time of day and day of week to the offer of a free COVID-19 antibody test. All individuals recruited at the lab will answer surveys.
Experimental Design Details
Not available
Randomization Method
Randomization was done in an office using excel and imperfect latin squares. Over a 6 week period, we randomized offers of testing by clinic (3 sites), time of day (8am-12pm and 1-5pm) and day of week within study week and randomized the order of the week.
Randomization Unit
Clinic x Time of Day (8am-12pm and 1-5pm) x day week.
Was the treatment clustered?
Yes
Experiment Characteristics
Sample size: planned number of clusters
180 clusters, where 1 cluster is a clinic x Time of Day (8am-12pm and 1-5pm) x day of week x week of study
Sample size: planned number of observations
5,000
Sample size (or number of clusters) by treatment arms
90 clusters receive antibody test offers
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)
We use data collected from another study "Monitoring elderly psychological well-being during the COVID-19 pandemic" for inputs into our calculations. Although the survey was fielded to a different sample (seniors nationwide), preventive health behaviors were measured identically. Thus, we power the current study using the index of preventive health measures described above. For respondents in California, we have a mean index of 5.375 (out of a possible score of 7) with a standard deviation of 1.69. Given $5 incentives for survey completion, we have a budget to field about 5000 surveys. With 2 clusters, assuming a 50% correlation within clusters, we can detect a change in the index of about 0.51 or about 9.4% of the mean. Assuming a 0% correlation within clusters, we can we can detect a change in the index of about 0.13 or about 2.4% of the mean. Since individuals are not coming to CCHS for COVID-19 testing, the intra-cluster correlation in COVID-19 beliefs and behaviors is likely between these two thresholds. Thus, realistically, we should have sample size to detect changes of closer to about 5% of the mean index.
IRB
INSTITUTIONAL REVIEW BOARDS (IRBs)
IRB Name
University of Southern California Institutional Review Board
IRB Approval Date
2020-06-23
IRB Approval Number
UP-20-00443
Analysis Plan

There are documents in this trial unavailable to the public. Use the button below to request access to this information.

Request Information