Making Health Research Matter: A Call to Increase Attention to External Validity.

Most of the clinical research conducted with the goal of improving health is not generalizable to nonresearch settings. In addition, scientists often fail to replicate each other's findings due, in part, to lack of attention to contextual factors accounting for their relative effectiveness or failure. To address these problems, we review the literature on assessment of external validity and summarize approaches to designing for generalizability. When investigators conduct systematic reviews, a critical need is often unmet: to evaluate the pragmatism and context of interventions, as well as their effectiveness. Researchers, editors, and grant reviewers can implement key changes in how they consider and report on external validity issues. For example, the recently published expanded CONSORT figure may aid scientists and potential program adopters in summarizing participation in and representativeness of a program across different settings, staff, and patients. Greater attention to external validity is needed to increase reporting transparency, improve program dissemination, and reduce failures to replicate research.