Quick Identification of the Risk of Psychosis: The Italian Version of the Prodromal Questionnaire-Brief



Antonio Preti1, 2, 3, *, Andrea Raballo4, Georgios D. Kotzalidis5, Rosanna Scanu2, Tamara Muratore2, Mersia Gabbrielli2, Debora Tronci2, Carmelo Masala2, Donatella Rita Petretto2, Mauro G. Carta1
1 Center of Liaison Psychiatry and Psychosomatics, University Hospital, University of Cagliari, Cagliari, Italy
2 Section on Clinical Psychology, Department of Education, Psychology, Philosophy, University of Cagliari, Cagliari, Italy
3 Genneruxi Medical Center, Cagliari, Italy
4 Department of Psychology, Psychopathology and Development Research, Norwegian University of Science and Technology (NTNU), Trondheim, Norway
5 NESMOS Department, Sapienza University, School of Medicine and Psychology, Sant'Andrea Hospital, Rome, Italy

Abstract

Background:

Diagnosing people during the prodromal phase of an incipient psychosis can improve the chance of better outcome. In busy clinical settings, the ideal tool is a brief, easy-to-complete self-report questionnaire.

Objective:

To test the psychometric properties of the Italian version of one of the most used screening tools for the identification of the risk of psychosis, the Prodromal Questionnaire-Brief (PQ-B).

Methods:

Cross-sectional design. A convenience sample of college students was enrolled via snowball procedure (n=243; men: 45%). After understanding and signing the consent form, the participants received a booklet containing the following questionnaires: the 21-item Prodromal Questionnaire-Brief (PQ-B); the 12-item General Health Questionnaire (GHQ-12), and the 74-item Schizotypal Personality Questionnaire (SPQ). Receiver operating characteristic (ROC) analysis was used to assess the capacity of the PQ-B to identify individuals at risk of psychosis as independently defined based on the combination of GHQ-12 and SPQ thresholds.

Results:

The Italian version of the PQ-B revealed good internal consistency, test-retest reliability, and adequate convergent and divergent validity. The Youden method retrieved a cut-off = 7 for the PQ-B frequency score and a cut-off = 22 for the PQ-B distress score. Both PQ-B scores had a perfect (99%) negative predictive value.

Conclusion:

The PQ-B is a promising screening tool in two-stage protocols. The major advantage of the PQ-B is to exclude cases that are unlikely to be at risk of psychosis.

Keywords: PQ, Screening, Schizophrenia, Psychosis, Ultra high risk.


Abstract Information


Identifiers and Pagination:

Year: 2018
Volume: 14
Publisher Item Identifier: EA-CPEMH-2018-8

Article History:

Received Date: 16/2/2018
Revision Received Date: 18/4/2018
Acceptance Date: 23/4/2018
Electronic publication date: 30/4/2018
Collection year: 2018

© 2018 Preti et al.

open-access license: This is an open access article distributed under the terms of the Creative Commons Attribution 4.0 International Public License (CC-BY 4.0), a copy of which is available at: https://creativecommons.org/licenses/by/4.0/legalcode. This license permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.


Correspondence: Address correspondence to this author at the Center of Liaison Psychiatry and Psychosomatics, University Hospital, University of Cagliari, via Costantinopoli 54, 09123 Cagliari, Italy; Tel: 0039 070 6093498; E-mail: antolink@yahoo.it