Changes in adherence and treatment costs following initiation of oral or depot typical antipsychotics among previously non‐adherent patients with schizophrenia

Abstract

This study assessed the impact of depot formulations on adherence and treating costs in the naturalistic treatment of previously non-adherent outpatients with schizophrenia. Data were taken from the European Schizophrenia Outpatient Health Outcomes (SOHO) study. Medication adherence and treating costs during an 18-month follow-up were assessed and compared for non-adherent patients initiated on depot typical (n = 262) or oral typical antipsychotics (n = 169) as monotherapy at the index visit. Multivariate analyses were employed to adjust for differences between the two groups at the index visit. Of the previously non-adherent patients, more than half of patients initiated on depot typicals (55%) remained adherent to medication during follow-up, whereas the equivalent was 39% for patients initiated on oral typicals. Logistic regression also showed higher odds of being adherent among the former group (Odds ratio = 1.84; 95% CI = 1.19-2.85). In addition, total costs incurred by this group during 18 months were only half those incurred by patients initiated on oral typicals (£3645 vs £7817, p < 0.05) CONCLUSIONS: Depot formulations of typical antipsychotics appeared to improve medication adherence and reduce treatment costs, compared with oral formulations, in the treatment of non-adherent patients. adherence was assessed by the treating psychiatrist using a single-item.