Psychometric evaluation of the psychosis screening questionnaire in South Africa with attention to overlap between symptoms and normative cultural beliefs.

Abstract

We evaluated the 5-item Psychosis Screening Questionnaire (PSQ) against a diagnostic gold standard in South Africa. 1885 adults at primary and tertiary health facilities were screened with the PSQ and diagnosed using the Mini International Neuropsychiatric Interview-V. Minor adaptations were required of both instruments to distinguish between psychiatric symptoms and normative cultural beliefs. We assessed internal consistency, criterion validity and sensitivities and specificities for identifying current or lifetime hypomanic or manic episode and/or psychotic disorders. The PSQ only yielded acceptable criterion validity for lifetime hypomanic or manic episode. A positive PSQ screen yielded sensitivities of 74.36%, 55.00%, and 64.68% for lifetime hypomanic or manic episode, psychotic disorder, and any SMD, respectively. Given the overlap between symptoms and normative cultural beliefs, preemptive framing was required to improve the cultural understanding and relevance. With these adaptations, the translated PSQ functioned adequately for hypomanic or manic episode, but not for psychotic disorder.