Figure 6.
False negative rates. Error bars show 95% confidence intervals. * indicates a statistically significant difference (p < 0.05).
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.