To assess in a naturalistic setting the effectiveness of olanzapine within 12-month follow-up, in schizophrenic and bipolar outpatients.In this abstract, baseline patient characteristics are provided and compared between the olanzapine coated (OC) and orally disintegrating (OD) formulations to investigate prescribing patterns.

ZEN is a 1-year prospective, observational study, carried out in France, Germany and Greece from April’07 to May’09. Baseline patient characteristics were compared using Students-t, Chi2 or Fisher's-exact tests. Patients who started olanzapine prior to 60 days before the study or for whom the olanzapine formulations could not be determined were excluded from the analysis.

903 of the 927 enrolled patients were analyzed (45.2% paranoid schizophrenia, 32.2% bipolar disorder). 410 patients received the OC form and 493 the OD form. Distribution of gender was comparable across groups (55.1% male).OC patients were older than OD patients (43.1 vs 39.1 years, p< 0.001) and had a longer mean duration of illness (14.4 vs 11.2 years; p< 0.001). OD patients were more severely ill irrespective of diagnosis (p< 0.006, mean CGI schizophrenia=4.2 vs 3.8, CGI bipolar disorder=4.1 vs 3.7). At initiation, daily dose in OD patients was higher (15.0 vs 10.6 mg, p< 0.0001). Based on the 6-level SUMD scale, more OC patients were clearly aware of having a mental disorder (44.7% vs 32.9%; p< 0.001). OC patients were more compliant at baseline (mean MARS score 6.6 vs 5.5, p< 0.001).

Baseline characteristics show that the utilization of each oral form of olanzapine in outpatient setting is associated with different patient profiles.