The Community Assessment of Psychic Experiences:Optimal cut-off scores for detecting individuals with a psychotic disorder

Abstract

OBJECTIVES: The need for a brief screening tool for psychosis is widely recognized. The Community Assessment of Psychic Experiences (CAPE) is a popular self‐report measure of psychosis, but a cut‐off score that can detect those most likely to fulfill diagnostic criteria for psychotic disorder is not established. METHODS: A case–control sample from the Genetic Risk and Outcome of Psychosis Project study (N = 1375, healthy individuals, n = 507, and individuals with a psychotic disorder, n = 868), was used to examine cut‐off scores of the CAPE with receiver operating curve analyses. We examined 27 possible cut‐off scores computed from a combination of scores from the frequency and distress scales of the various factors of the CAPE. RESULTS: The weighted severity positive symptom dimension was most optimal in detecting individuals with a psychotic disorder (>1.75 cut‐off; area under the curve = 0.88; sensitivity, 75%; specificity, 88%), which correctly identified 80% of the sample as cases or controls with a diagnostic odds ratio of 22.69. CONCLUSIONS: The CAPE can be used as a first screening tool to detect individuals who are likely to fulfill criteria for a psychotic disorder. The >1.75 cut‐off of the weighted severity positive symptom dimension provides a better prediction than all alternatives tested so far