Economic evaluations of antidepressant treatments: a national cohort study in Taiwan
Given the marked personal, social and economic impacts, depressive disorder creates significant demands on individuals, health service providers and society as a whole. Antidepressant drugs remain the mainstay of treatment for depression for most people in contact with healthcare services and the last 20 years have seen dramatic changes in antidepressant prescription patterns. Initially, there was an increase in the use of the selective serotonin reuptake inhibitors (SSRIs) and subsequently, other novel antidepressant agents with different pharmacological mechanisms entered the market. Given the range of choices, clinicians must decide about which is the most appropriate intervention for their patients. To this end, knowledge regarding the relative cost-effectiveness and cost-utility of individual antidepressants is important.Therefore, in this thesis, a systematic review was first conducted to assess methodological approaches in economic evaluations of pharmacological treatments using database analyses. Based on the National Health Insurance Research Database in Taiwan, a cost analysis was conducted to identify which demographic and clinical characteristics are associated with healthcare costs of patients with depression. Compared to patients prescribed SSRIs, those prescribed older antidepressants had lower total and psychiatric costs, while patients prescribed serotonin norepinephrine reuptake inhibitors (SNRIs), and other newer antidepressants had higher total and psychiatric costs. The baseline comorbidities of cardiovascular diseases (CVD) and headache were also associated with healthcare costs over the 12-month period. To further assess the longer-term economic impacts, a set of database outcome statuses (sustained treatment-free status, continuous treatment, and late re-contact) were then applied to explore factors associated with outcome status following initial treatments and to examine healthcare costs over the following three years by outcome status. Theresults showed the initial outcome status could exert an impact on total healthcarecosts in the second and third years after commencing treatments. Finally, cost-effectiveness and cost-utility were compared between different categories of antidepressant treatments and also to test whether and how the presence of CVD, the most prevalent comorbid physical illness in this cohort, affects these results. The results showed that SSRIs are more cost-effective than tricyclic antidepressants and SNRIs regardless of comorbid CVD. There are various limitations to be considered in these analyses, including the limited scope of costs, the lack of clinical information, and the adoption of utility scores from previous studies. Further efforts to elucidate the relationship between depression treatments, costs and outcomes for longer period of follow up are warranted.
Networked Digital Library of Theses and Dissertations