Longer-term treatment of patients with bipolar disorder: a 9-month observational study in Central and Eastern Europe, the Middle East and Africa.

Objective: To compare the longer-term outcomes of pharmacological treatment of patients with a diagnosis of bipolar affective disorder currently suffering a manic or hypomanic episode prescribed olanzapine or non-olanzapine medication in naturalistic, clinical practice settings in Bosnia-Herzegovina, Slovakia, Slovenia, Turkey, Saudi Arabia and Egypt.

Research Design And Methods: Prospective, observational, non-interventional study conducted over 9 months. Inpatients or outpatients who initiated or changed oral bipolar mania medication were grouped into (1) those prescribed olanzapine at baseline (n = 569) and (2) those not prescribed olanzapine (n = 325).

Main Outcome Measure(s): The change from baseline in the Clinical Global Impression Severity scale for bipolar disorder (CGI-BP-S), the rates of symptomatic response and remission (based on CGI-BP-S) and the frequency and nature of treatment-emergent adverse events. Analyses included (1) linear or logistic regression, with adjustment for confounders, based on the last observation carried forward and (2) weighted repeated measures models that adjusted for treatment switching and patient drop-out.

Results: When results were adjusted for treatment switching and patient drop-out, patients prescribed olanzapine had significantly better CGI-BP-S scores (mean difference = -0.24; 95% confidence interval [CI] -0.33, -0.16; p < 0.001) and significantly greater odds of treatment response (odds ratio [OR] = 1.86; 95% CI 1.31, 2.65; p < 0.001) and symptom remission (OR = 1.65; 95% CI 1.18-2.32; p = 0.003) than those not prescribed olanzapine. The frequency of most adverse events decreased in both groups. Patients prescribed olanzapine had significantly greater weight gain from baseline (mean increase = 2.66 kg; 95% CI 2.35, 2.98) compared with those not prescribed olanzapine (mean increase = 1.85 kg; 95% CI 1.51, 2.19; p < 0.001).

Conclusions: Inclusion of olanzapine is of benefit for pharmacological treatment of patients with bipolar disorder. However, the favourable outcomes observed cannot be directly attributed to olanzapine alone because of the high prevalence of polypharmacy in the patient population.