Treatment, health care utilization and health outcomes among primary care patients with generalized anxiety disorder in the United Kingdom
Abstract
The purpose of this study was to determine treatment patterns for primary care patients with Generalized Anxiety Disorder (GAD) in the United Kingdom. Associations between drug treatments, demographic characteristics, clinical outcomes, resource utilization and other economic outcomes were examined. A 12-month retrospective study using a sample of GAD patients from the General Practice Research Database during 1997–99 was conducted. 2,678 patients treated with benzodiazepines (38.1%), serotonin reuptake inhibitors (SRIs) (11.5%), tricyclic antidepressants (TCAs) (13.0%), beta-blockers (30.4%), buspirone (3.3%) and thioxanthene (3.3%) were included. Benzodiazepines were more frequently prescribed to women (p < 0.048), older patients (p < 0.0001), patients with GAD history (p < 0.0153) and history of substance abuse (p < 0.0197), and to patients from Wales, Scotland and Northern Ireland compared to England (p < 0.001). Among 2,499 patients treated with benzodiazepines, SRIs, TCAs and beta-blockers, 20.6 percent experienced some treatment failure, defined as treatment switches or augmentations and/or mental disease related referrals, hospitalizations or emergency visits. Treatment success, physician recorded patient improvement, was seen in 5.4 percent of the patients. There were no differences in likelihood of treatment failure or time-to-treatment failure between drug classes after controlling for risk factors including age, gender, region, dose, prior mental or somatic illnesses and health services utilization. Physician recorded improvement was six times more likely in patients treated with SRIs (p < 0.0001) than in those treated with benzodiazepines after adjusting for risk factors. SRIs also had higher improvement rates than TCAs and beta-blockers (both p < 0.01). However, patients treated with beta-blockers received significantly fewer prescriptions and incurred significantly fewer outpatient visits compared to other groups (both p < 0.0001) after adjustment for risk factors. Costs related to GAD drugs and mental-health services use were significantly higher in the SRIs group primarily due to higher drug costs (£168 [£152–£184], p < 0.0001). Likelihood of mental-health related work-loss was significantly higher in patients treated with TCAs (7.7%) compared to those on beta-blockers (3.5%). Mean mental-health related absence among all GAD patients was 2.4 days and 55.7 days among patients with at least one mental-health related work absence. No differences between treatment groups were noted after adjustment for risk factors. Given the results of this study, there is no clear evidence that treatment with any particular drug provides better long-term clinical outcomes among GAD patients although physicians recorded higher improvement following treatment with SRIs. Treatment costs were substantial, and higher in GAD patients treated with SRIs than in any other group. Despite likely incomplete recording of work-absence data, GAD is responsible for significant work-loss.
Degree
Ph.D.
Advisors
Thomas, Purdue University.
Subject Area
Pharmaceuticals|Mental health|Health care
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