Table 5.
Low (partial) vacuum tube vs. regular (full) vacuum tube (IV starts only).
| Study | Study quality rating | Effect size rating |
|---|---|---|
| Sixsmith et al. (2000) | Fair | Substantial |
| Cox et al. (2004) | Good | Substantial |
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.