Schizophrenia symptoms and functioning in patients receiving long-term treatment with olanzapine long-acting injection formulation: a pooled analysis

Background: This analysis of pooled data evaluates treatment outcomes of patients with schizophrenia receiving maintenance treatment with olanzapine long-acting injection (OLAI) by means of a categorical approach addressing the symptomatic and functional status of patients at different times. Methods: Patients were grouped into 5 categories at baseline, 6 months, and 12 months. Shifts between categories were assessed for individual patients and factors associated with improvement were analyzed. 1182 patients from 3 clinical trials were included in the current analysis. Results: At baseline, 434 (36.8%) patients had minimal Positive and Negative Syndrome Scale (PANSS) symptoms but seriously impaired Heinrich Carpenter's Quality of Life Scale (QLS) functioning; 303 (25.6%) had moderate to severe symptoms and seriously impaired function; 208 (17.6%) had mild to moderate symptoms but good functioning, and 162 (13.7%) had minimal symptoms and good functioning. Baseline category was significantly associated with Clinical Global Impression - Severity (CGI-S), extrapyramidal symptoms, working status, age, and number of previous episodes. The majority of all patients starting OLAI treatment maintained or improved (62% at 6 months and 52% at 12 months) their symptom and functioning levels on OLAI maintenance treatment. Less than 8% of the patients showed worsening of symptoms or functioning. An improvement in category was associated with high PANSS positive and low CGI-S scores at baseline. Conclusions: We present evidence that a composite assessment of schizophrenic patients including symptom severity and functioning is helpful in the evaluation of maintenance treatment outcomes. This approach could also be useful for the assessment of treatment options in clinical practice. The trials from which data are reported here were registered on clinicaltrials.gov as NCT00088491, NCT00088465, and NCT00320489.