Which question addresses external validity?

Which question addresses external validity?

• A. Will costs be the same for patients in other clinics?
• B. Are the study outcomes worth the time and effort?
• C. Will patients in other clinics have a similar outcome?
• D. Were instruments properly calibrated and outcomes properly measured?

Answer: (C)

External validity asks whether the study results would hold in settings beyond where the research was done. If patients in other clinics have similar outcomes, that shows the findings can be generalized to different clinical settings. The option that directly asks about similar outcomes in other clinics is the best match for testing this generalizability. Calibrating instruments and ensuring outcomes were measured properly pertains to accuracy and consistency of measurement within the study, which supports internal validity rather than how broadly the results apply. Whether costs would be the same in other clinics touches on generalizability of economic aspects, but it’s a secondary angle; the clearest test of external validity is whether the outcomes themselves are likely to be the same elsewhere. Whether the study outcomes are worth the time and effort relates to usefulness or relevance, not to applying findings to other settings.

External validity asks whether the study results would hold in settings beyond where the research was done. If patients in other clinics have similar outcomes, that shows the findings can be generalized to different clinical settings. The option that directly asks about similar outcomes in other clinics is the best match for testing this generalizability.

Calibrating instruments and ensuring outcomes were measured properly pertains to accuracy and consistency of measurement within the study, which supports internal validity rather than how broadly the results apply. Whether costs would be the same in other clinics touches on generalizability of economic aspects, but it’s a secondary angle; the clearest test of external validity is whether the outcomes themselves are likely to be the same elsewhere. Whether the study outcomes are worth the time and effort relates to usefulness or relevance, not to applying findings to other settings.