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.
The tree structure of PROMED with '1 to n' problem histories. Each box represents one database record for a problem event. Problem 1 has two events; problem 2 has 5 events, etc. The history of each problem starts with a black box and ends with a red; the blue are intermediate events.
