"We used a validated questionnaire": What does this mean and is it an accurate statement in urologic research?

Abstract

OBJECTIVE: To educate a clinical audience of what the specific meaning of the term "validated questionnaire" means from a research methodology perspective when used in a journal article or a conference presentation. METHODS: To emphasize what is meant by the term "validated questionnaire," we reviewed the most commonly used prostate-specific, patient-reported, outcome assessment instruments and discuss which have been appropriately validated for use in patients having surgery for localized prostate cancer. RESULTS: Not all the prostate-specific instruments used to assess outcomes after surgical treatment for localized prostate cancer have been validated for use in this population. In particular, the Sexual Health Inventory for Men and the International Prostate Symptom Score-American Urological Association-7, which are commonly used by clinicians to measure potency and urinary function, respectively, have not been validated for use in a population of patients having surgery for localized prostate cancer. CONCLUSION: Although patient-reported outcome assessment instruments are frequently used in the urologic literature, little consideration has been given to ensure that users understand why a questionnaire must be validated and what the term "validated" actually means from a research methodology perspective when used in this context. Whether an instrument displays appropriate measurement properties is not a fixed attribute but is dependent on the context and population being studied. Studies using questionnaires that have not been validated in the population of interest may be subject to measurement error, and any conclusions drawn cannot be made with total confidence. Clinicians should consider this when reading journal articles and designing study protocols.