METHODS: PE studies in schizophrenia published after 2000 were identified through Medline, Embase, congresses websites and grey literature. Utility values for schizophrenia states, adverse events (AEs), and cardiovascular (CV) events were extracted.

RESULTS: After screening 1892 records, 69 cost-utility studies were systematically identified, of which 32 studies reported utility values considered. They used utility values from 21 different sources. Indirect utility elicitation methods was considered in 9 studies, using EQ-5D, HUI3, QWB-SA or IHQL questionnaires, and direct elicitation in 8 studies, using visual analogue scale, time-trade off or standard gamble approach. Other ones did not specify the source considered. There were 31 studies considering utility for schizophrenia states. Globally, schizophrenia states could be classified into stable schizophrenia (from 0.800 to 0.919) and relapse (0.479 to 0.762) sometimes combined with outpatient and inpatient states. Other values were used for adherence, type of antipsychotic or subsequent relapses. Utility for AEs were considered in 22 studies, including extrapyramidal symptom (0.422 to 0.888), weight gain (0.766 to 0.959), and diabetes (0.760 to 0.888). Values for sedation, sexual dysfunction, hyperprolactinemia, hyperlipidemia, and metabolic syndrome were also considered. Seven studies considered utilities for CV events, including non-fatal myocardial infarction (0.730 to 0.760) and non-fatal stroke (0.580 to 0.690). Thirteen studies considered utility decrements, including states for AE (n=13), relapse (n=2) and hospitalization (n=1).

CONCLUSIONS: High heterogeneity exists for utility values used in current PE studies in schizophrenia. Although this heterogeneity may represent different preferences of different populations (general population or patients’ perspective, etc.) for the same states, there may be heterogeneity between utilities that are supposed to be comparable (same state and same perspective).