Jörg Mahlich, Masamichi Nishi, Yoshimichi Saito

The cost of schizophrenia in Japan is high and new long-acting injectable (LAI) antipsychotics might be able to reduce costs by causing a reduction of hospital stays. We aim to estimate budget effects of the introduction of a new 1-month LAI, paliperidone palmitate, in Japan. A budget impact analysis was conducted from a payer perspective. The model took direct costs of illness into account (ie, costs for inpatient and outpatient services, as well as drug costs). The robustness of the model was checked using a sensitivity analysis. According to our calculations, direct total costs of schizophrenia reach 710,500 million yen a year (US$6 billion). These costs decrease to 691,000 million yen (US$5.9 billion) 3 years after the introduction of paliperidone palmitate. From a payer point of view, the introduction of a new treatment for schizophrenia in Japan helps to save resources and is not associated with a higher financial burden.