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.
Risk of bias in included studies. *Study identified from ClinicalTrials.gov. †Study received financial support from pharmaceutical companies. ‡Authors received financial support from pharmaceutical companies (e.g., consultation). §Neither study nor authors received financial support from pharmaceutical companies.
