The cost of relapse in patients with schizophrenia in the European SOHO (Schizophrenia Outpatient Health Outcomes) study

Background: Relapse in schizophrenia is one of the greatest burdens of the illness. Aims: To estimate the costs associated with relapse in a pan-European naturalistic setting. Method: The SOHO study is a 3-year, prospective, observational study of 10,972 outpatients with schizophrenia across 10 European countries. The cost of resource use (inpatient stay, day care, psychiatrist visits and medication) for those who ever relapsed in three years was compared to those who never relapsed. One-year costs for both groups were also compared for a more stringent comparison. The analyses were adjusted for patient characteristics and took account of non-normality of the cost data by using a log-link function. UK unit costs were applied to resource use. The analysis was repeated after multiple imputation for missing data. Results: Costs incurred by patients who ever relapsed (14,055) pound during three years were almost double to those incurred by patients who never relapsed (7417) pound. 61% of the cost difference was accounted for by hospital stay. The impact of relapse was even greater in the 1-year cost comparison, Results from the additional analysis with imputed missing data remained largely consistent. Conclusions: Our findings confirm the significant economic burden of relapse, and show such costs were mainly due to hospital stay. Nevertheless, the use of UK unit costs requires caution when interpreting this costing in the context of a specific country, as resource use and their associated costs will differ by country, (C) 2009 Elsevier Inc. All rights reserved.