title: Usefulness of the CAPE-P15 for detecting people at ultra-high risk for psychosis: Psychometric properties and cut-off values.
abstract: A need for a brief, easy to complete self-report questionnaire to detect people at ultra-high risk for psychosis (UHR) in busy clinical settings has been recognised. Our aim was to explore whether the Community Assessment of Psychic Experiences - Positive 15-items Scale (CAPE-P15) could be used as a screening tool to identify people at UHR in a clinical setting. Our objectives were to confirm the CAPE-P15 factorial structure as well as its reliability and determine cut-off values for the detection of such individuals using the Comprehensive Assessment of At-Risk Mental States (CAARMS), a commonly used clinical interview for the detection of UHR. 165 participants aged between 13 and 18 referred to the General Hospital of Vienna were included in the analysis. 50.9% of the sample were "CAARMS-positive" and 49.1% "CAARMS-negative". The Youden method determined CAPE-P15 cut-off values for UHR detection of 1.47 for both frequency of and distress associated with psychotic experiences. The cut-off value of 1.47 for frequency showed sensitivity of 77%, specificity of 58%, a positive predictive value of 66% and a negative predictive value of 71%; whilst for distress it showed sensitivity of 73%, specificity of 63%, a positive predictive value of 69% and a negative predictive value of 66%. Good reliability and the previously suggested three-correlated factor model as well as an alternative bi-factor model of the CAPE-P15 were confirmed. The CAPE-P15 seems to be a promising screening tool for identifying people who might be at UHR in busy clinical settings.
authors.affiliation: Department of Psychiatry, University of Cambridge, Cambridge, Herchel Smith Building, CB2 0SZ Cambridge, UK.
authors.forename: Akvile
authors.initials: A
authors.lastname: Bukenaite
authors.affiliation: Department of Psychiatry, University of Cambridge, Cambridge, Herchel Smith Building, CB2 0SZ Cambridge, UK.
authors.forename: Jan
authors.initials: J
authors.lastname: Stochl
authors.affiliation: Department of Psychiatry and Psychotherapy, Clinical Division of Social Psychiatry, Medical University Vienna, 1090 Vienna, Austria.
authors.forename: Nilufar
authors.initials: N
authors.lastname: Mossaheb
authors.affiliation: Orygen, National Centre of Excellence in Youth Mental Health, 3052 Parkville, Melbourne, VIC, Australia; Centre for Youth Mental Health, University of Melbourne, 3052 Parkville, Melbourne, VIC, Australia.
authors.forename: Miriam R
authors.initials: MR
authors.lastname: Schäfer
authors.affiliation: Department of Child and Adolescent Medicine, Medical University Vienna, 1090 Vienna, Austria.
authors.forename: Claudia M
authors.initials: CM
authors.lastname: Klier
authors.affiliation: Department of Neurology, Alfred Krupp Hospital Rüttenscheid, 45131 Essen, Germany.
authors.forename: Jana
authors.initials: J
authors.lastname: Becker
authors.affiliation: Department of Child and Adolescent Psychiatry, Medical University Vienna, 1090 Vienna, Austria.
authors.forename: Monika
authors.initials: M
authors.lastname: Schloegelhofer
authors.affiliation: Department of Psychiatry and Psychotherapy, Clinical Division of Biological Psychiatry, Medical University Vienna, 1090 Vienna, Austria.
authors.forename: Konstantinos
authors.initials: K
authors.lastname: Papageorgiou
authors.affiliation: Department of Psychiatry, University Hospital of Salamanca, IBSAL Neurosciences, University of Salamanca, 37007 Salamanca, Spain.
authors.forename: Angel L
authors.initials: AL
authors.lastname: Montejo
authors.affiliation: Department of Psychiatry, University of Cambridge, Cambridge, Herchel Smith Building, CB2 0SZ Cambridge, UK.
authors.forename: Debra A
authors.initials: DA
authors.lastname: Russo
authors.affiliation: Department of Psychiatry, University of Cambridge, Cambridge, Herchel Smith Building, CB2 0SZ Cambridge, UK; CAMEO Early intervention in Psychosis Services, Cambridgeshire and Peterborough NHS Foundation Trust, CB21 5EF Cambridge, UK.
authors.forename: Peter B
authors.initials: PB
authors.lastname: Jones
authors.affiliation: Department of Psychiatry, University of Cambridge, Cambridge, Herchel Smith Building, CB2 0SZ Cambridge, UK; CAMEO Early intervention in Psychosis Services, Cambridgeshire and Peterborough NHS Foundation Trust, CB21 5EF Cambridge, UK; Norwich Medical School, Faculty of Medicine and Health Sciences, University of East Anglia, NR4 7TJ Norwich, UK. Electronic address: jp440@cam.ac.uk.
authors.forename: Jesus
authors.initials: J
authors.lastname: Perez
authors.affiliation: Orygen, National Centre of Excellence in Youth Mental Health, 3052 Parkville, Melbourne, VIC, Australia; Centre for Youth Mental Health, University of Melbourne, 3052 Parkville, Melbourne, VIC, Australia.
authors.forename: G Paul
authors.initials: GP
authors.lastname: Amminger
mesh_terms: D000293:Adolescent; D005260:Female; D006801:Humans; D008297:Male; D008962:Models, Theoretical; D011569:Psychiatric Status Rating Scales; D011594:Psychometrics; D011618:Psychotic Disorders / Q000175:diagnosis* / Q000523:psychology*; D015203:Reproducibility of Results; D012307:Risk Factors; D057566:Self Report
keywords: CAARMS; CAPE; CAPE-P15; Psychosis; Screening; Ultra-high risk