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A
.gov website belongs to an official
government organization in the United States.
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A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
Strength of evidence
| Strength of evidence | |
|---|---|
| A | Category I evidence |
| B | Category II evidence or extrapolated recommendation from category I evidence |
| C | Category III evidence or extrapolated recommendation from category I or II evidence |
| D | Category IV evidence or extrapolated recommendation from category I or II or III evidence |
