» Articles » PMID: 39223760

An Item Response Theory Analysis of the Psychosis Screening Questionnaire in Ethiopia

Overview
Specialty Psychiatry
Date 2024 Sep 3
PMID 39223760
Authors
Affiliations
Soon will be listed here.
Abstract

Aim: Few psychosis screening instruments have been tested for use in Africa, yet appropriate tools can increase the detection of self-reported psychotic symptoms, improve the detection of psychosis and impact its prognosis.

Method: The construct validity and factor structure of Psychosis Screening Questionnaire (PSQ) were tested with confirmatory factor analysis (CFA) and item response theory (IRT) in a sample of 1928 Ethiopian adults without any history of psychosis. We tested a unidimensional model with and without an item on mania. For IRT, unidimensional latent structure one-parameter logistic (1PL) and two-parameter (2PL) logistic models were tested and compared for relative fit using a likelihood-ratio test.

Result And Discussion: The prevalence of lifetime positive screens was 2.8% in an Ethiopian sample of adults from a general medical setting. A unidimensional model demonstrated good fit for the PSQ, (CFI = 0.993, TLI = 0.986 and RMSEA = 0.025). For IRT, a 2PL model was the best fitting one. IRT tests of item difficulty and discrimination parameters showed that paranoia had the highest discrimination and lowest difficulty ( ), likely to be endorsed at low levels of psychotic features. Thought insertion had the highest item difficulty ( ). Overall, the measure captures the psychosis construct at higher levels of the latent trait and may be suited for detecting moderate to severe levels of psychosis.

Conclusion: The PSQ is found to have good construct validity in screening for psychosis among Ethiopian adults. Future studies may focus on the diagnostic validity of the PSQ comparing it with a structured clinical interview.

References
1.
Sullivan S, Kounali D, Cannon M, David A, Fletcher P, Holmans P . A Population-Based Cohort Study Examining the Incidence and Impact of Psychotic Experiences From Childhood to Adulthood, and Prediction of Psychotic Disorder. Am J Psychiatry. 2020; 177(4):308-317. DOI: 10.1176/appi.ajp.2019.19060654. View

2.
Jenkins R, Njenga F, Okonji M, Kigamwa P, Baraza M, Ayuyo J . Psychotic symptoms in Kenya--prevalence, risk factors, and relationship with common mental disorders. Int J Environ Res Public Health. 2012; 9(5):1748-56. PMC: 3386585. DOI: 10.3390/ijerph9051748. View

3.
Shibre T, Teferra S, Morgan C, Alem A . Exploring the apparent absence of psychosis amongst the Borana pastoralist community of Southern Ethiopia. A mixed method follow-up study. World Psychiatry. 2010; 9(2):98-102. PMC: 2911089. DOI: 10.1002/j.2051-5545.2010.tb00286.x. View

4.
Fekadu A, Hanlon C, Gebre-Eyesus E, Agedew M, Solomon H, Teferra S . Burden of mental disorders and unmet needs among street homeless people in Addis Ababa, Ethiopia. BMC Med. 2014; 12:138. PMC: 4147171. DOI: 10.1186/s12916-014-0138-x. View

5.
Anderson K . Towards a public health approach to psychotic disorders. Lancet Public Health. 2019; 4(5):e212-e213. DOI: 10.1016/S2468-2667(19)30054-4. View