An official website of the United States government
Here's how you know
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.
Baseline difference between cohorts on the absolute difference of CPM (a), percent change of CPM (b), 5th pain rating at 50°C (c), and pre-CPM and post-CPM (d). Their respective standard deviation are shown for a, and c.