Abstract
Our study aimed to assess the psychometric validity of the conceptual disorganization item and other items of the Brief Psychiatric Rating Scale (BPRS) for detecting disorganized speech in patients with schizophrenia. We included 357 schizophrenia patients with disorganized speech and 1082 without disorganized speech from the survey centers in India, Indonesia, Japan, Malaysia, and Taiwan, using the data from the Research on Asian Psychotropic Patterns for Antipsychotics (REAP-AP) study. After adjusting the effects of confounding variables, a binary logistic regression model was fitted to identify BPRS items independently associated with disorganized speech. Receiver operating characteristic (ROC) curves were used to identify optimum cut-off scores and their sensitivities and specificities for detecting disorganized speech. After adjusting the effects of confounding variables, the fitted binary logistic regression model indicated that conceptual disorganization (P < 0.0001), uncooperativeness (P = 0.010) and excitement (P = 0.001) were independently associated with disorganized speech. The ROC curve revealed that the conceptual disorganization item could accurately detect disorganized speech in patients with schizophrenia both separately and in combination with uncooperativeness and excitement. The subscale for conceptual disorganization, uncooperativeness and excitement items in the BPRS is a promising psychometric tool for detecting disorganized speech.