What does external validity refer to in research?

External validity refers to the extent to which the results of a study can be generalized to, or have relevance for, settings, populations, or circumstances beyond the specific conditions of the research. When a study achieves high external validity, its findings can be extrapolated to a broader context, indicating that the results are not limited to the particular sample or environment in which the research was conducted.

For example, if a clinical trial is conducted on a specific group of patients with a unique demographic profile, the ability to apply these findings to other groups of patients or different healthcare settings hinges on the study's external validity. A high degree of external validity suggests that the conclusions drawn from the study are applicable in real-world situations, thereby enhancing the utility and impact of the research in practice.

Factors that contribute to external validity include the diversity of the study sample, the relevance of the setting, and how representative the conditions are of the broader population. This is essential in healthcare research, where findings need to be applicable to various patient groups, care environments, and healthcare systems to improve overall health outcomes.