Figure 1.
Study Flowchart. April 2020 (baseline—T0), July 2020 (T1), October 2020 (T2), January 2021 (T3), and April 2021 (T4).
Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.