Psychometric properties of the 15-item positive subscale of the community assessment of psychic experiences

Abstract

ObjectiveA new 15-item version of the positive subscale of Community Assessment of Psychic Experiences (CAPE-P15) has been recently proposed and used to measure psychotic-like experiences. The wide application of this scale is thought to be feasible and cost-effective, due to its manageable length and higher level of internal consistency. However, its psychometric properties have not been well established. MethodsThe validity and reliability of the CAPE-P15 were assessed in 1255 college students across two time frames (over a lifetime and in the past month). Confirmatory factor analysis was used to confirm its construct validity and measurement invariance across sex. Pearson's correlation analysis was used to investigate its clinical and concurrent validity. We also calculated the test-retest reliability and internal consistency to verify the reliability of the scale. Finally, telephone interviews were performed to explore the consistency between self-reported and interview-verified CAPE-P15 scores. ResultsThe scale has adequate psychometric properties in terms of construct, clinical and concurrent validity; measurement invariance across sex; test-retest reliability; and internal consistency. We also confirmed considerably high consistency between self-reported and interview-verified CAPE-P15 scores. ConclusionsThis study confirms that the CAPE-P15 is a valid and reliable instrument for assessing psychotic-like experiences in college students, both over a lifetime and in the past month. This overall assessment of the CAPE-P15 supports its more widespread use in this population. However, further research is needed to assess its utility in clinical settings, as well as in general population.