A longitudinal study of patient- and observer-rated quality of life in schizophrenia

Patient-rated life satisfaction and observer-rated quality of life (ORQOL) appear to have different determinants in patients with schizophrenia, although most studies conducted to date have used cross-sectional methods or related clinical dimensions at one time point with quality of life (QOL) measured at another. The aim of this study was to investigate the relationship between changes in patient-rated QOL (PRQOL) and ORQOL over time and changes in clinical variables. Two hundred and thirty-one patients taking part in the Schizophrenia Care Assessment Program (SCAP) study at Dandenong in Australia were included in this analysis. Subjective ratings of several domains of social functioning and life satisfaction were taken from the SCAP instrument and comparisons made with data from the QOL Scale rated by research staff, as well as several psychopathology measures. Changes in these scores over 1 year were correlated to investigate relationships between measures. Weak correlations were seen between changes in PRQOL and ORQOL domains. Patient-rated domains related most closely to depressive symptoms (Montgomery-Asberg Depression Rating Scale scores) whereas observer-rated domains related to both negative symptoms and depressive symptoms. Positive psychotic symptoms had little effect on either domain. Longitudinal data appear to confirm that PRQOL and ORQOL are not closely related and may have differing determinants in patients with schizophrenia. They should be considered as separate and complementary outcome variables and utilized accordingly.