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

ABSTRACT

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.

Keywords: :

• Bipolar disorder
• antipsychotic agents
• olanzapine
• treatment outcomes

Transparency

Declaration of funding

This study was sponsored by Eli Lilly and Company. In compliance with the Uniform Requirements for Manuscripts, established by the International Committee of Medical Journal Editors, the sponsor of this study did not impose any impediment, directly or indirectly, on the publication of the study's results.

Declaration of financial/other relationships

G.H. and T.T. have disclosed that they are employees of Eli Lilly, manufacturer of olanzapine. M.Z. has disclosed that he is a consultant to Eli Lilly and Pfizer; is a recipient of honoraria and travel reimbursement from Eli Lilly; and serves on the speakers bureau of Pfizer, Janssen-Cilag, Ozone, Sanofi-Aventis and Lundbeck. O.K. has disclosed that he is a recipient of research grants from Pfizer, Sanovel Pharmaceuticals; is a member of the speakers bureau/advisory board of Johnson & Johnson, GlaxoSmith Kline, Lilly and Pfizer; is a recipient of honoraria and speakers fees from Wyeth, BMS, Lundbeck, Sanofi-Aventis, Sanovel, Abdi_İbrahim, Egis, Eczacıbaşı-Zentiva; and is a consultant to and recipient of honoraria and travel reimbursement from Eli Lilly. A.S. has disclosed that he is a recipient of sponsorship from Johnson & Johnson; is a recipient of research grant funding from Pfizer, Liundbeck and BMS; and serves as an advisor for Johnson & Johnson and Lundbeck. A.A. has disclosed he is the recipient of research grant funding from Eli Lilly. T.O. and A.K. have disclosed that they have no relevant financial relationships.

All peer reviewers receive honoraria from CMRO for their review work. Peer Reviewer 1 and Peer Reviewer 2 have disclosed that they have no relevant financial relationships.

Acknowledgments

The authors acknowledge the independent medical writing assistance provided by Dr Serina Stretton of ProScribe Medical Communications, funded from an unrestricted financial grant from Eli Lilly and Company. ProScribe's services complied with international guidelines for Good Publication Practice.

The data reported here were presented, in part, at the following meetings: Proceedings of the Collegium Internationale Neuropsychopharmacologicum (CINP), 9–13 July 2006 Chicago, IL, USA [Int J Neuropsychopharmacol July 2006; 9(Suppl 1):S105]; Proceedings of the 2nd Biennial Conference for the International Society of Bipolar Disorders (ISBD), August 2–4, 2006, Edinburgh, UK [Bipolar Disorder Poster Session: Clinical Trials 2006;8(Suppl 1):32]; and Proceedings of the 5th European Stanley Conference on Bipolar Disorder (ESCBD), 5–7 October 2006, Barcelona, Spain.