Responsiveness of the Personal and Social Performance scale in patients with schizophrenia.

The responsiveness (ability to detect change) of the Personal and Social Performance scale (PSP) is largely unknown, limiting its use as an outcome measure. The purpose of this study was to examine both internal and external responsiveness of the PSP in patients with schizophrenia in the acute phase. Eighty patients were administered the PSP and the Clinical Global Impression-Severity scale (CGI-S) at admission and at discharge. We used the standardized effect size, the standardized response mean, and paired t-test for examining internal responsiveness. We examined the correlations between the changes in scores of the PSP and those of the CGI-S using Pearson's r for validating the external responsiveness. The results showed that the standardized effect sizes and standardized response means of the PSP were 0.74-1.74 and 0.68-1.72, respectively. The paired t-tests showed statistically significant difference (p<0.001). Moderate to good correlations (r=0.35-0.74) were found among the changes of the PSP with those of the CGI-S. The PSP showed substantial internal responsiveness and sufficient external responsiveness in patients with schizophrenia receiving treatment in the acute phase. The PSP appears useful as an outcome measure for detecting changes of social functioning over time.