OBJECTIVES: Long-acting injectable (LAI) antipsychotic drugs (APDs) have been introduced to increase therapeutic adherence compared to corresponding oral formulation. This cost sub analysis aimed to estimate the health care costs related to schizophrenia in patients who had started aripiprazole long-acting injectable (LAI) treatment in the DOMINO study.

METHODS: DOMINO study was an observational, retrospective, non-interventional study that included 261 schizophrenic patients who were initiated with aripiprazole LAI (index date) at least 6 months before the data collection and follow-up visit (inclusion visit). The economic model were developed considering the health resources associated to ambulatory visits, emergency department visits, hospitalizations, non-pharmacological and pharmacological therapies in terms of Italian reimbursed tariff or price from the NHS perspective in a 6 follow-up from the index date.

RESULTS: The average cost per patient has been estimated equal to € 3,070.3 (54.9% and 24.8% related to aripiprazole LAI treatment and hospitalization cost respectively).The economic model demonstrates that the main cost-predictor was the persistence with aripiprazole LAI treatment (€ 3,000.1 for persistent patient vs € 3,509.1 for non-persistent, p=0.0122)) and the level of Clinical Global Impression-Severity scale (CGI-S) at the enrolment visit (€ 2,806.1 for patients with CGI-S score ≤ 3 vs € 3,262.3 for patients with CGI-S score ≥ 4, p=0.0084). Cost difference between persistent and non-persistent patients was -€ 830.5 for CGI-S score ≤ 3 patients (p=0.2852) and -€ 274.6 for CGI-S score ≥ 4 patients (p=0.0169).

CONCLUSIONS: Our results suggest that schizophrenia-related cost per patients on treatment with aripiprazole LAI is associated with CGI-S score and the persistence to aripiprazole LAI treatment. The ability to maintain schizophrenic patients persistent to the treatment and in a lower CGI-S score could reduce the average direct costs sustained by the Italian NHS.