OBJECTIVES: There is increasing emphasis on understanding impact of core symptoms and functioning on well-being and quality-of-life (QOL) to achieve holistic outcomes in schizophrenia. The short-form-12 (SF-12) is a widely used generic measure of self-reported health-related QOL (HRQOL). Relationship of SF-12 as an outcome measure of HRQOL in patients with schizophrenia with clinically relevant symptom rating scales for schizophrenia was evaluated.

METHODS: Post-hoc analyses were conducted from a randomized, placebo-controlled, relapse prevention phase 3 study (NCT01529515) of paliperidone palmitate 3-monthly (PP3M) in patients with schizophrenia. SF-12 (version 2.0) was administered before open-label transition phase and end of double-blind phase. SF-12 subscales (bodily pain, general health, mental health, physical health, vitality, role physical, role mental, social functioning) and summary scores (mental component summary [MCS], physical component summary [PCS]) were normalized with a range of 0-100 and population mean (SD) of 50(10). Linear regression for change in SF-12 and common schizophrenia symptom rating scales (Positive and Negative Syndrome Scale [PANSS], Personal and Social Performance [PSP], Clinical Global Impression – Severity [CGI-S] and Involvement Evaluation Questionnaire [IEQ]) on change in MCS/PCS, with baseline MCS/PCS added as a covariate, were conducted.

RESULTS: Improvements in PANSS positive (p<0.0001; R²=0.330), negative (p=0.002; R²=0.305) and in PSP (p<0.0001; R²=0.326) and CGI-S (p=0.0034; R²=0.302) were significantly associated with improvements in MCS but were not associated with improvements in PCS (PANSS [negative: p=0.786; R²=0.163; positive: p=0.501; R²=0.165], PSP (p=0.345; R²=0.167) and CGI-S (p=0.9268; R²=0.163). Improvements in IEQ urging were significantly associated with improvements in mental health subscale score (p=0.0143; R²=0.2564).

CONCLUSIONS: A clear and significant relationship was observed between the SF-12 MCS score and validated psychiatric rating scales (PANSS, PSP and CGI-S) of schizophrenia. Other components and subscales of SF-12 did not show clear relationship. Change in symptoms measured by SF-12 MCS may reflect a change in patient’s QOL.