WAVE-bd addresses limitations of previous longitudinal bipolar disorder (BD) studies (mainly single disease phase- or treatment-focused).

To provide real-world data on BD treatment practices across countries.

To report descriptive analyses of patients’ profiles and use of quetiapine extended and immediate release (XR and IR).

Multicentre, non-interventional, longitudinal study of BD-I/II patients, with ≥1 mood episode in the preceding year (minimum 9 months’ follow-up). Sample was representative of BD populations from Austria, Belgium, Brazil, France, Germany, Portugal, Romania, Turkey, Ukraine and Venezuela.

During the index episode, 662/2896 (22.9%) patients took quetiapine (326 XR, 336 IR); baseline analysis of this population revealed higher incidence rates of previous hospitalisations (hospitalisations/person-year; diagnosis to study-start) in patients taking XR at index event (0.29) vs those taking IR (0.22) (p<0.0001). Analysis of all episodes occurring during WAVE-bd in quetiapine patients revealed more frequent prescription of XR vs IR in manic (56.2% vs 43.8%) and depressive (60.5% vs 39.5%) episodes. XR prescriptions also exceeded IR prescriptions during euthymia (62.0% vs 38.0%). XR was more frequently started before, and continued after, episodes (mania: 46.5% [XR] vs 23.4% [IR], p<0.0001; and depression: 48.1% [XR] vs 34.0% [IR], p=0.0002). Average dose (mg/day) was higher for XR vs IR (mania: 493.7 vs 423.4 [p=0.0194]; depression: 371.0 vs 269.0 [p<0.0001]).

Quetiapine XR and IR use differs in BD. The XR formulation appears to be prescribed more than IR, both for patients previously hospitalised more frequently, and irrespective of disease phase. AstraZeneca-funded study; Clinical Trials Registry: NCT01062607.