Validity of subjective versus objective quality of life assessment in people with schizophrenia

BACKGROUND: Quality of life (QoL) is considered an important outcome in health research. It can be rated by the patient, or by an external assessor. We wished to identify the predictors of any discrepancies between these two approaches in people with schizophrenia. METHODS: Patients with DSM schizophrenia and related disorders (N = 80) completed both patient-rated (Lancashire Quality of Life Profile; LQOLP) and assessor-rated (Heinrich’s Quality of Life Scale; QLS) measures of QoL. RESULTS: Patient-rated (LQOLP) and assessor-rated (QLS) measures showed a modest correlation (r = 0.38). In a regression analysis, independent predictors of subjectively-rated QoL being higher than objectively-assessed QoL in the same patient, were low insight score (BIS), negative symptoms (PANSS), absence of depression (CDSS), and less positive attitude toward prescribed treatment (DAI). CONCLUSIONS: In people with schizophrenia, scores on objectively- and subjectively-rated measures of quality of life can differ markedly. When comparing subjective to objective assessments, patients with depressive symptoms will value their QoL lower, and those with low insight will value their QoL higher. This has important implications for the utility and interpretation of QoL measures in schizophrenia.