2011 Volume 2 Pages 45-55
Purpose: To assess the clinical and functional outcomes of olanzapine treatment for schizophrenia in a 1-year naturalistic study of inpatients and outpatients in Japan.
Methods: We used data from a large (N=1850), prospective, observational study of Japanese schizophrenia patients who were initiated on olanzapine. Clinical and functional outcomes of inpatients and outpatients were contrasted using chi-square tests, t-tests, and mixed models for repeated measures controlling for baseline demographics.
Results: At study entry, 43.2% were outpatients and 56.8% were inpatients. The mean (± SD) dosage for olanzapine was 11.4 ± 5.7 mg/day. Outpatients were significantly younger and more likely to be female. The most common reason for switching to olanzapine was poor medication efficacy (outpatients: 71.8%, inpatients: 74.3%), followed by medication intolerability (outpatients: 21.5%, inpatients: 28.0%). Most outpatients (63.8%) and inpatients (71.6%, p=.003) completed the study. Outpatients and inpatients experienced clinically and statistically significant improvements in global symptom severity, positive, negative, depressive, and cognitive symptoms, health-related quality of life, paid work, and social activities. Many outpatients (60.9%) and inpatients (50.5%, p<.001) demonstrated symptomatic response, with 51.0% of outpatients and 32.8% of inpatients (p<.001) experiencing remission. Mean weight gain was 2.06 kg, with 26.5% of patients experiencing clinically significant weight gain (≥ 7%).
Discussion: In this 1-year naturalistic study, inpatients and outpatients who initiated treatment with olanzapine experienced significant improvements in their clinical and functional outcomes. One-fourth of patients experienced clinically significant weight gain. Current findings highlight the favorable benefit to risk profile of olanzapine for the treatment of schizophrenia in Japan.