Validation of the Korean Version of the Psychosis Screener to Identify Patients with Psychosis

OBJECTIVE: This study aimed to validate the Korean version of a short screening tool for psychosis as the first stage in finding undiagnosed psychosis in the community.

METHODS: The sample contained 126 consecutive psychiatric outpatients in National Medical Center, Seoul, Korea, between July 20 and July 22, 2020. The Psychosis Screener (PS) comprises 7 items covering psychotic symptoms. The presence of each psychotic symptom was determined by a trained mental health professional and coded "yes" or "no." Two psychiatrists reviewed the medical records independently and extracted the ICD-10-based diagnoses. Any differences between the two clinicians were resolved by consensus, and the agreed diagnosis was used as a gold standard in the study.

RESULTS: Among 126 psychiatric outpatients who were enrolled in a consecutive manner during the study period, the proportion of psychosis was 15.1%. The PS showed 78.9% sensitivity and 72.0% specificity when the optimal cut-off was 2, indicating that a score of 2 or more on the screener identified a likely case of psychosis. The area under the curve for the PS was 0.78 (95% CI: 0.67-0.87).

CONCLUSION: The Korean version of the PS has an ability to discriminate between those who meet the diagnostic criteria for psychosis and those who do not in a high-prevalence group.