To a broader concept of remission: rating the health-related quality of life in bipolar disorder

BACKGROUND: The relationship between remission and quality of life in bipolar disorder is incompletely understood. This study aimed to determine cut-points on the 36-item Short-Form Health Survey (SF-36) and the European Quality of Life Index (EQ-5D) that corresponded with an objective clinical measure of remission in bipolar disorder patients. METHODS: Data from a 2-year prospective observational study of bipolar and schizoaffective patients were analysed. Concordant with previous research, the Clinical Global Impression-Bipolar Version (CGI-BP) was used as an index of remission, specifically the severity scores of 1 (normal, not at all ill) and 2 (borderline mentally ill). The mean SF-36 standardized mental component (SMC) and standardized physical component (SPC) total scores as well as the EQ-5D index score that corresponded with a CGI-BP severity score of 1 or 2 were determined.
RESULTS: The mean SF-36 score that corresponded with a CGI-BP severity score of 1 or 2, was below 50 for the SPC (49.3) and below 49 for the SMC (48.3). The mean EQ-5D score that corresponded with a CGI-BP severity score of 1 or 2 was below 0.88 (0.87). LIMITATIONS: Although the initial sample is sufficiently large (n=240), 49 patients scored 1 and 2 on the CGI-S, of which 12 had schizoaffective disorder. CONCLUSIONS: This study suggests that a cut-off score of ≥50 for the SPC and ≥49 for the SMC of the SF-36 and ≥0.88 for the EQ-5D index approximates a CGI-BP definition of remission.