Outcome measures
To examine the ability to predict non-response at the endpoint by the magnitude of PANSS total score improvement at earlier assessment (week 2 or week 4), receiver operating characteristic (ROC) curves with area under the curve (AUC) values were calculated. The predictive values, including total accuracy, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV), were calculated for response status at an earlier assessment (week 2 or week 4) to predict later (week 8) response or non-response, referring to previous literature [Non-response rate to antipsychotic medication, change from baseline to week 8 in PANSS total score, and rate of reduction in PANSS total score after 8 weeks were used for efficacy evaluation. Non-response was defined as a < 20% reduction of the PANSS total score from baseline to week 8. The PANSS total score reduction rate was calculated as (baseline PANSS total score − follow-up PANSS total score)/(baseline PANSS total score − 30) × 100% [