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.
Documentation of literature search
| Database | Number of retrieved references |
|---|---|
| MEDLINE (Ovid) | 7,041 |
| Embase (Ovid) | 11,387 |
| Cochrane Central Register of Controlled Trials (Wiley) | 2,449 |
| Scopus (Elsevier) | 18,049 |
| Number of references before deduplication: | 38,926 |
| Number of references after deduplication: | 23,244 |
