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.
Probability of detecting an increase in death rate when the rate increases by a factor of 1.1, 1.5, 2, and 4. For example, for 90% probability of detecting a doubling of death rate from a standard rate of 10% to 20%, 16 expected deaths are required at standard rate—that is, 160 operations
