Table 1. Databases and numbers of articles extracted.
| Database | Number of articles |
|---|---|
| PubMed | 68 |
| MEDLINE | 95 |
| Other sources* | 4 |
*Personal files of one author.
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.