| State here method used to generate allocation and reasons for grading | Grade (circle) |
| Low risk of bias (Random) High risk of bias (e.g. alternate) Unclear |
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.