case definition
Standardized criteria used to determine whether an individual qualifies as a case in an epidemiological study.
Full Definition
Case definition establishes the specific diagnostic criteria, symptom thresholds, and temporal requirements that determine whether a study participant is classified as having the psychiatric condition of interest. In psychiatric epidemiology, case definitions may be based on diagnostic manuals (DSM, ICD), validated screening instruments, or clinical assessments. A clear, reproducible case definition is essential for study validity and enables comparison across different research studies. Case definitions may include primary cases (meeting full criteria) and secondary definitions (subsyndromal or probable cases) depending on study objectives.
Usage
Usage note: Always specify the diagnostic framework and time criteria used in case definitions.
In Context
- "The case definition required meeting DSM-5 criteria for major depressive episode within the past 12 months." — epidemiological study protocol
- "Researchers used both narrow and broad case definitions to assess sensitivity of findings." — methodological comparison