Experimental Design Details
Approximately 10,000 adult subjects will be recruited from the Contra Costa Health Plan (CCHP) via baseline survey. Subjects who complete the baseline survey will be randomized to the following arms:
1. Control Arm (n=2,500)
2. Informational Arm: state/treatment as usual message vs. safety and effectiveness information vs. information on consequences of going unvaccinated, race and/or gender concordant or discordant [7,500]
Each of these arms will be interacted with a financial incentive of $10 (N=2,500) or $50 (N=2,500) and, separately with a convenient link to the county public vaccine appointment scheduling system highlighted for participants (N=5,000).
The above treatments are designed to test the role of the following on vaccine take-up:
• Financial incentives [N=5,000] vs. no financial incentives [N=5,000]
o 2,500 will be randomized to a $10 incentive and 2,500 to a $50 incentive
• Convenient scheduling link highlighted [N=5,000] vs. not [N=5,000]
• Messaging [N=7,500] vs not [2,500]
o Message type: treatment as usual [N=2,500] vs. safety and effectiveness [N=2,500] vs. consequences of not vaccinating [N=2,500]
• Race concordant [N=2,500] vs. race discordant messenger [N=2,500]
• Gender concordant [N=2,500] vs. gender discordant messenger [N=2,500]
We will obtain survey data on preventative health behaviors, including mask-wearing, hand washing, and willingness to vaccinate. We will obtain data on vaccine take-up from the EMR and California's Immunization Registry (CAIR).