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.
Subject-specific approximate entropy (ApEn) values. Individuals differed significantly in the temporal irregularity of their sleep hours (diamonds) and bouts (triangles) (P < 0.001). There was greater irregularity in sleep hours compared to sleep bouts (P = 0.004).
