Reasons and clinical outcomes of antipsychotic treatment switch in outpatients with schizophrenia in real-life clinical settings: the ETOS observational study

Background:Patients under antipsychotic treatment for schizophrenia commonly exhibit poor adherence to treatment, high rates of treatment discontinuation, and frequent treatment changes. The ETOS study aimed to identify the reasons leading physicians to decide to switch antipsychotic treatment in outpatients with schizophrenia and to evaluate the outcome of this switch.

Methods:ETOS was an observational 18-week (four visits) study in outpatients 18 to 65 years old, diagnosed with schizophrenia according to Diagnostic and Statistical Manual of Mental Disorders - 4th edition criteria at least 6 months prior to enrolment, who were initiated on a new antipsychotic monotherapy treatment within the 2 weeks prior to enrollment. A total of 574 patients were recruited by 87 hospital- and office-based physicians. Ethical approval was obtained prior to study initiation (NCT00999895).

Results:The final analysis included 568 patients, 39.0 ± 11.2 years old with mean disease duration of 11.7 years. The male-to-female ratio was 53:47. The main reason for switching antipsychotic treatment was lack of tolerability (n = 369, 65.0%), followed by lack of efficacy (n = 249, 43.8%). Following treatment switch, 87.9% of patients (n = 499) showed meaningful clinical benefit by achieving a Clinical Global Impression-Clinical Benefit score of ≤4 at the final visit. By the end of the study, total Positive and Negative Syndrome Scale, Clinical Global Impression-Improvement, Clinical Global Impression-Severity, and Simpson-Angus Scale scores demonstrated significant mean decreases of 31.69, 0.70, 1.14, and 11.30, respectively (all p < 0.0001). Treatment adherence remarkably improved.

Conclusion:In the ETOS study, switch of antipsychotic monotherapy for reasons relating to lack of efficacy and/or tolerability was associated with significantly improved clinical benefit and significant increase of patients' adherence to treatment.