A clinical research practice datalink analysis of antidepressant treatment patterns and health care costs in generalized anxiety disorder

Abstract

Objective: To describe real-life prescription patterns, health care resource use, and costs in adults with generalized anxiety disorder (GAD) initiating antidepressant (AD) treatment in the United Kingdom.

Methods: A retrospective longitudinal cohort study using data from Clinical Research Practice Datalink was conducted. Adults with incident prescription of an AD (index date) between January 1, 2006, and June 30, 2010, and with a diagnosis of GAD within the 2 months preceding or following the index date were included. Patients with a diagnosis of schizophrenia or bipolar disorder were excluded.

Results: A total of 29,131 patients with GAD were included in the analysis. Their mean age was 48.5 ± 15.5 years, and two thirds were women. GAD-licensed ADs (i.e., escitalopram, paroxetine, venlafaxine XR, and duloxetine) represented only 12.5% of the index AD prescriptions. At least one anxiolytic was prescribed for 23.5% of the patients. Only 33.2% of the patients continued index AD treatment over the study period. Discontinuation occurred for 46.0% of the patients, after a mean of 3.7 months of treatment. The health care costs were £338.4 per patient in the 6 months before the index date and £984.6 in the 9 months after the index date. Psychiatric hospitalization (relative risk = 4.18; 95% CI 3.53-4.96; P < 0.001) and duloxetine as index treatment (relative risk = 1.85; 95% CI 1.30-2.63; P < 0.001) were the main determinants of increased costs for these patients.

Conclusions: The significant rate of AD discontinuation and associated treatment duration indicate unmet needs among patients with GAD. As described in American studies, substantial health care costs were also observed in this study.

Keywords: General Research Practice Database; antidepressant; generalized anxiety disorder; health care costs; health care resource use.