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.
Required sample size in the absence of population substructure. The sample size is indicated by n. The required sample size to achieve 0.8 power at the significance level α = 10−8 has been calculated as a function of t, the number of time points, and ρ, the correlation between measurements at two different time-points.
