External Validity: The Next Step for Systematic Reviews?

Background: Systematic reviews-which identify, assess, and summarize existing research-are usually designed to determine whether research shows that an intervention has evidence of effectiveness, rather than whether an intervention will work under different circumstances. The reviews typically focus on the internal validity of the research and do not consistently incorporate information on external validity into their conclusions.

Objectives: In this article, we focus on how systematic reviews address external validity.