Applicability of the Chinese version of the 16-item Prodromal Questionnaire (CPQ-16) for identifying attenuated psychosis syndrome in a college population.

AIM

The aim of this study was to examine the reliability, validity, sensitivity and specificity of the Chinese version of the 16-item Prodromal Questionnaire (CPQ-16) for identifying attenuated psychosis syndrome (APS) in a college population.

METHODS

The participants were recruited from a university. Five hundred seventy-nine students completed the CPQ-16 and the Symptom Checklist-90. One class (n = 79) was randomly selected to be retested with the CPQ-16 after 2 weeks. A randomly selected group of 49 individuals who tested positive and 50 individuals who tested negative were interviewed using the Structured Interview for Prodromal Syndromes (SIPS).

RESULTS

The internal consistency reliability was good (Cronbach's α = 0.72). The test-retest reliability was 0.88. The total score on the CPQ-16 was moderately to highly correlated with the total score on the Symptom Checklist-90 and all of the subscales (r = 0.39-0.67, P < 0.001). A cut-off CPQ-16 score of 9 was used to differentiate between those with a APS diagnosis on the SIPS versus those with no SIPS diagnoses; this cut-off value yielded 85% sensitivity, 87% specificity, a positive predictive value of 63% and a positive likelihood ratio of 6.69. The area under the ROC curve (AUC) was significant for the CPQ-16 total score (AUC = 0.93, SE = 0.026, 95% CI = 0.87-0.98, P < 0.001). Based on the proposed cut-off score, the CPQ-16 yielded a positive rate of 5.0% (29/579).

CONCLUSIONS

The CPQ-16, administered in a face-to-face interview, demonstrated high reliability and the ability to identify college students at risk for psychosis.