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.
Best quality synthesis applied on the extracted results
| Level of evidence | Consistent findings in multiple (≥2) high-quality studies | Strong evidence |
| Consistent findings in one high-quality study and at least one fair-quality study or consistent findings in multiple fair-quality studies | Moderate evidence | |
| Only one study available or inconsistent findings in multiple studies (≥2) | Inconsistent evidence |
