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

OBJECTIVE

This study assessed the impact of depot formulations on adherence and treating costs in the naturalistic treatment of previously non-adherent outpatients with schizophrenia.

METHODS

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.

RESULTS

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.

LIMITATION

adherence was assessed by the treating psychiatrist using a single-item.