ABSTRACT
OBJECTIVES: The objective of this work was to study characteristics and clinical treatment patterns of bipolar disorder (BD) patients admitted to hospital and treated with quetiapine (immediate-release [IR] or extended-release [XR] formulations). METHODS: BD patients admitted to hospital and prescribed quetiapine IR were followed by linking two Swedish nationwide registries; the hospitalization and drug dispense registries [ClinicalTrials.gov identifier: NCT01455961]. The study period was from 1 January 2008, to end of 31 December 2011. Data was primarily analysed using descriptive methods. RESULTS: Quetiapine IR was used in 1761 patients of whom 1303 subsequently switched to XR (switch XR) and 458 remained on IR (continuous IR). At baseline, Switch XR patients were younger (-3.3 years), more frequently employed (+7.1%), had higher prevalence of single depressive episodes (+6.7%) and anxiety disorders (+5.8%), lower mean daily IR dose (-19.3%) and fewer medications for somatic disorders (-7.5%) than continuous IR patients. During follow up, the number of concomitant psychiatric medications was lower in switch XR patients (-6%) and higher in continuous IR patients (+6%). Mean daily quetiapine dose was 21% higher in switch XR versus continuous IR patients. Prescriptions of lower quetiapine dosages calculated below 50 mg per day in the XR switch and IR continuous groups were seen in 8% versus 10% of the patients, respectively. CONCLUSIONS: Differential use of quetiapine XR and IR in bipolar disorder patients with different and important characteristics was demonstrated. Patients who were switched to quetiapine XR had a higher psychiatric disease burden, were younger and had a higher degree of employment. These differences demonstrate the heterogeneity among bipolar disorder patients and indicate the need in clinical practice for individualized treatment to reduce the risk for both patient and society related losses.
ABSTRACT
OBJECTIVES: The aim of the study was to describe temporal changes in bipolar disorder during 20 years within the Swedish population and to investigate clinical and socioeconomic characteristics, drug treatment, and mortality among patients with bipolar disorder. METHODS: We conducted a retrospective, nationwide registry study (the Swedish Population Register) that included all patients diagnosed with bipolar disorder (1991-2010) and linked individual data from the Swedish National Patient Register, the National Prescribed Drug Register, and the Population Register (NCT01455961). A cross-sectional cohort analysis was performed for years 2006 versus 2009. Data were analyzed using descriptive statistics. RESULTS: During the study period, the annual incidence of diagnosed bipolar disorder increased 3.5-fold, and patients were diagnosed at a younger age. Mortality among patients with bipolar disorder was twice that of the general population. Compared to an age-standardized population, 30% fewer patients with bipolar disorder were available for work. Among the 40% employed, 64% reported sick leave (46% >100 days/year). Despite similar education levels, disposable income was lower compared to the general population. The most commonly preceding psychiatric diagnoses were depressive or anxiety disorders. Comparing the data for 2006 and 2009 demonstrated similar somatic comorbidity burdens and socioeconomic levels. There was also a decrease in dispensed antipsychotic medications and lithium, while antiepileptic prescriptions increased slightly. Antidepressant dispenses remained virtually unchanged. CONCLUSIONS: In Sweden, the incidence and prevalence of diagnosed bipolar disorder have increased during the last 20 years. Compared to the general population, these patients had similar education levels, lower employment levels, less disposable income, more sick leave, and twice the mortality. A trend towards earlier diagnosis, more use of antidepressants, and less use of lithium was seen.
