Clinical management and burden of bipolar disorder: results from a multinational longitudinal study (WAVE-bd).

Bipolar disorder is a mood disorder which requires complex treatment. Current treatment guidelines are based on the results of published randomized clinical trials and meta-analyses which may not accurately reflect everyday clinical practice. This multi-national, multi-centre, observational cohort study describes clinical management and clinical outcomes related to bipolar disorder in real-life settings, assesses between-country variability and identifies factors associated with clinical outcomes. Adults from 10 countries in Europe and South America who experienced at least one mood episode in the preceding 12 months were included. Overall, 2896 patients were included in the analyses and followed for at least 9 months across a retrospective and prospective study phase. Main outcome measures were the number and incidence rate of mood episodes (relapses and recurrences) and healthcare resource use including pharmacological treatments. Relapses and recurrences were reported in 18.2 and 40.5% of patients, respectively; however, the reported incidence rate of relapses was higher than that of recurrences [1.562 per person-year (95% CI 1.465-1.664) vs. 0.691 per person-year (95% CI 0.657-0.726)]. Medication use was high during all episode types and euthymia; the percentage of patients receiving no medication ranged from 11.0% in mania to 6.1% in euthymia. Antipsychotics were the most commonly prescribed drug class in all disease phases except for patients with depression, where antidepressants were more frequently prescribed. Visits to the psychiatrist were the most frequently used healthcare resource. These results provide a description of treatment patterns for bipolar disorder across different countries and indicate factors related to relapse and recurrence.