Background: The aim of this study was to assess the reasons for discontinuing or continuing olanzapine in patients with schizophrenia, from the perspectives of the patients and their clinicians.

Methods: The Reasons for Antipsychotic Discontinuation/Continuation (RAD) is a pair of questionnaires assessing these reasons from the perspectives of patients and their clinicians.  Outpatients with schizophrenia (n = 199) who were not acutely ill participated in a 22-week open-label study of olanzapine from Nov 2006 to Sep 2008.  Reasons for continuing or discontinuing olanzapine (on a 5-point scale), along with the single most important reason and the top primary reasons, were identified.  Concordance between reasons given by patients and clinicians was assessed.

Results: The top primary reasons for continuing olanzapine were patients' perceptions of improvement, improvement of positive symptoms, and improved functioning.  The study discontinuation rate was low (30.2%), and only a subset of patients who discontinued reported reasons for medication discontinuation.  The top primary reasons for discontinuing olanzapine were insufficient improvement or worsening of positive symptoms, adverse events, and insufficient improvement or worsening of negative symptoms.  Ratings given by patients and clinicians were highly concordant.

Conclusions: The main reason for continuing or discontinuing olanzapine appears to be medication efficacy, especially for positive symptoms.  Reasons for medication discontinuation differ somewhat from reasons for continuation, with a high level of concordance between patient and clinician responses.

Authors are with Eli Lilly and Co., Inc.