Figure 1.
Relation of prediction window, observation window for use of data and the index and diagnosis dates for cases and the same relative times for controls.
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.