Clinical Evidence: Source Studies for Every Screening Tool

Why this matters

Peer-reviewed validation is what separates a clinical screening tool from an internet quiz. A validated instrument has been administered to a defined population, scored against an external reference standard (often a structured diagnostic interview), and published with reported psychometric properties such as sensitivity and specificity at specific cut points. Other researchers and clinicians can then use that evidence to decide whether the instrument fits their setting and to interpret a patient's score within a known error band.

Sensitivity is the proportion of people with the condition whose score falls at or above the cut point: a high-sensitivity test is useful for ruling out a condition when the score is low. Specificity is the proportion of people without the condition whose score falls below the cut point: a high-specificity test is useful for confirming a positive screen warrants further evaluation. No screening test is both perfectly sensitive and perfectly specific. That is one reason a positive screen is the beginning of a clinical conversation, not the end of one.

We also list license status because that affects what you, a clinician, or a researcher can do with an instrument. Pfizer-released tools (PHQ-9, PHQ-4, GAD-7) are free to use without permission. WHO instruments (AUDIT, AUDIT-C, ASRS, WHO-5) are public domain. U.S. Department of Veterans Affairs instruments (PCL-5, PC-PTSD-5) are in the public domain. Some instruments, such as DAST-10, retain copyright with the original author or institution and require permission for commercial reuse.

Where the published abstract did not state a sensitivity or specificity value, this page says so directly. The validation literature on some instruments is large and evolving, so values stated here reflect the original validation paper. Subsequent studies in different populations may report different operating characteristics, and clinical guidelines change over time.