FIGURE 1.
Study flowchart. Flowchart showing study participant selection. Of 21,004 participants in the 1999–2002 National Health and Nutrition Examination Survey (NHANES), 3,793 remained after fulfilling inclusion and exclusion criteria.
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.