This material is the copyright of the original publisher. Unauthorised copying and distribution is prohibited. Clin Drug Invest 2006; 26 (8): 447-457 ORIGINAL RESEARCH ARTICLE 1173-2563/06/0008-0447/$39.95/0  2006 Adis Data Information BV. All rights reserved. Cost-Effectiveness Analysis of Schizophrenia Relapse Prevention An Economic Evaluation of the ZEUS (Ziprasidone-Extended-Use-In-Schizophrenia) Study in Spain Miguel Bernardo, 1 Jose Ram´ on Azanza, 2 Carlos Rubio-Terr´ es 3 and Javier Rejas 4 1 Department of Psychiatry, Hospital Clinic i Provincial, Barcelona, Spain 2 Department of Pharmacology, Cl´ inica Universitaria de Navarra, Pamplona, Spain 3 HERO Consulting, Madrid, Spain 4 Department of Pharmacoeconomics and Health Outcomes Research, Medical Unit, Pfizer Espa ˜ na, Alcobendas, Madrid, Spain Objective: The aim of this study was to estimate the cost-effectiveness of Abstract schizophrenia relapse prevention in Spain using data from the ZEUS (Ziprasidone-Extended-Use-in-Schizophrenia) study. Methods: Treatment of schizophrenia was modeled over 1 year using a retrospec- tive deterministic model from the Spanish National Health System (NHS) per- spective (year 2005). The primary outcome was the probability of relapse occurring within a 52-week period of treatment with daily doses of ziprasidone 40–160mg versus placebo. Data were obtained from a randomised, double-blind clinical trial (n = 218 patients). Antipsychotic cost, concomitant medications to treat adverse events (for example extrapyramidal symptoms) and medical costs associated with adverse events were derived from the clinical trial results and a Spanish health cost database. The average cost of a relapse admitted to hospital in Spain (€3421) was obtained from a retrospective study. Results: The probability of psychosis relapse was 0.77 with placebo, and 0.43, 0.35, 0.36 and 0.38 with ziprasidone daily doses of 40, 80, 160mg and average dose, respectively (p < 0.01 vs placebo in all cases). The average annual incremen- tal cost per relapse avoided was €186 for the average dose, ranging from a saving of €557 (80 mg/day) to an incremental cost of €1015 (160 mg/day), and was lower in all cases than the minimum cost of a relapse (€2830). Conclusions: According to this evaluation, psychosis relapse prevention with ziprasidone is cost effective compared with no treatment from the Spanish NHS perspective. Ziprasidone therapy avoids a considerable number of relapses at a reasonable cost, producing cost savings.