Self- and observer-rated functioning and psychiatric readmission: findings from multicenter longitudinal data.

We examined self- and observer-rated functioning across four groups defined by psychiatric readmission status. Data were derived from Early Discharge and Prognostic Community Outcomes for Psychiatric Inpatients in Japan, including 483 patients discharged from acute psychiatric wards. Self-rated functioning (Sheehan Disability Scale, SDS) and observer-rated functioning (Personal and Social Performance Scale, PSP) were assessed at index admission, discharge, and 6- and 12-month follow-ups after discharge. Participants were divided into four groups: readmission at both follow-ups, readmission at 6-month follow-up, readmission at 12-month follow-up, and no readmission. Between-group and within-group changes were examined using generalized linear mixed models. For PSP, the no-readmission group showed significantly better scores than the readmission groups at 6-month (adjusted p = 0.002) and 12-month (adjusted p < 0.001) follow-ups. Excluding the group with readmission at both follow-ups, the remaining three groups demonstrated improvements across all time points through 12 months after discharge. For SDS, scores improved over time only in the no-readmission group (adjusted p < 0.001). These findings indicate that changes in functioning differed according to readmission status. Improvements were more pronounced in observer-rated functioning, whereas self-rated functioning showed limited change. This discrepancy may reflect differences between self- and observer-rated assessments.Clinical trial registration: This study was registered in the UMIN Clinical Trials Registry (UMIN000034220).