The construct validity of the Inventory of Psychotic-Like Anomalous Self-Experiences (IPASE) as a measure of minimal self-disturbance: Preliminary data.
Barnaby Nelson, Emily Li, David C Cicero, Łukasz Gawęda, Jessica A Hartmann, Danny Koren, Andrea Polari, Thomas J Whitford, Suzie Lavoie
Early intervention in psychiatry June 1, 2019 Peer reviewed DOI: 10.1111/eip.12711 via PubMed
Summary
The Inventory of Psychotic-Like Anomalous Self-Experiences (IPASE) shows strong construct validity as a self-report measure of minimal self-disturbance. In a sample of 46 participants (21 at ultra-high risk for psychosis, 14 with first-episode psychosis, and 11 healthy controls), the IPASE correlated very strongly with the gold-standard interview-based measure (EASE), with a correlation of 0.92. It also correlated strongly with general psychopathology and positive psychotic symptoms, moderately with negative symptoms, and weakly with manic symptoms. The IPASE may serve as a screening tool but cannot replace in-depth clinical assessment.
Study at a glance
| Design | cross-sectional validation study |
|---|---|
| Sample size | 46 |
| Population | ultra-high risk for psychosis patients, first episode psychosis patients, and healthy controls |
| Key finding | The IPASE demonstrated strong convergent validity with the EASE (r = 0.92) and appropriate discriminant validity, supporting its use as a screener for minimal self-disturbance but not as a replacement for clinical interview. |
Abstract
The Inventory of Psychotic-Like Anomalous Self-Experiences (IPASE) is a self-report measure of minimal self-disturbance. The aim of the current report was to assess the construct validity of the scale by examining its convergent validity with the gold-standard measure of minimal self-disturbance, the Examination of Anomalous Self-Experience (EASE), and its discriminant validity. The sample consisted of 46 participants (21 ultra-high risk for psychosis patients, 14 first episode psychosis patients, 11 healthy controls). Correlations between the clinical instruments were examined. The IPASE correlated strongly with general psychopathology and positive psychotic symptoms, moderately with negative symptoms, and weakly with manic symptoms. The strongest correlation (r = 0.92) was apparent between IPASE and EASE total scores. These preliminary data indicate construct validity of the IPASE, demonstrating both convergent and discriminant validity. The IPASE may be suitable as a screener measure for minimal self-disturbance, but should not be used as a replacement to measure the construct of minimal self-disturbance, which requires considerable psychopathological sophistication.