Early intervention of the Ultra High Risk (UHR) population is fundamentally important in preventing a potential psychosis. The two crucial steps in psychosis detection are the screening procedure...Show moreEarly intervention of the Ultra High Risk (UHR) population is fundamentally important in preventing a potential psychosis. The two crucial steps in psychosis detection are the screening procedure for (subclinical) psychotic symptoms, via the Prodromal Questionnaire (PQ) as well as a clinical interview, the Comprehensive Assessment of At-Risk Mental States. The aim of this study is to replicate an earlier study, by analyzing the psychometric properties of the PQ-16. More specifically, the cut off score will be evaluated, as well as the sensitivity, specificity, and positive predictive value in a new and larger sample. An additional research question will be examined, specifically whether the level of distress that patients experience per symptom has added value in classifying someone as UHR on the CAARMS. 31,734 participants were included in the analyses. A ROC analysis was used to display the connection and trade-off between clinical sensitivity and specificity for every possible cut-off score. In this study, the most suitable cut off score was 6, with a sensitivity of 70%, a specificity of 60%, a positive predictive value of 30.7 and a negative predictive value of 88.6. Additional ROC curves were plotted to measure various levels of distress; the highest AUC value being 0.64. Therefore, the level of distress on the PQ-16 does not have additional value in predicting UHR on the CAARMS. To conclude, due to the sufficient psychometric properties and clinical benefits, the PQ-16 remains an accessible and feasible tool to screen for subclinical psychotic symptoms. Future research should consider further replication, including an equal range of PQ scores in order to generalize to a wider population.Show less
