Abstract
BACKGROUND: The response to therapeutics varies widely in patients with depression and anxiety, making selection of an optimal treatment choice challenging. IDgenetix(®), a novel pharmacogenomic test, has been shown to improve outcomes by predicting the likelihood of response to different psychotherapeutic medications. OBJECTIVE: The objective of this study was to estimate the cost effectiveness of implementing a novel pharmacogenomic test (IDgenetix(®)) to guide treatment choices in patients with depression and/or anxiety compared with treatment as usual from the US societal perspective. METHODS: We developed a discrete event simulation to compare clinical events, quality-adjusted life-years, and costs of the two treatment strategies. Target patients had a Hamilton Rating Scale for Depression Score ≥ 20 and/or a Hamilton Rating Scale for Anxiety score ≥ 18 at baseline. Remission, response, and no response were simulated based on the observed rates in the IDgenetix(®) randomized controlled trial. Quality-adjusted life-years and direct and indirect costs attributable to depression and anxiety were estimated and compared over a 3-year time horizon. We conducted extensive deterministic and probabilistic sensitivity analyses to assess the robustness of the results. RESULTS: The model predicted cumulative remission rates of 78 and 66% in IDgenetix(®) and treatment as usual groups, respectively. Estimated discounted quality-adjusted life-years were 2.09 and 1.94 per patient for IDgenetix(®) and treatment as usual, respectively, which resulted in 0.15 incremental quality-adjusted life-years (95% credible interval 0.04-0.28). The total costs after accounting for a US$2000 test cost were US$14,124 for IDgenetix(®) compared with US$14,659 for treatment as usual, suggesting a US$535 (95% credible interval - 2902 to 1692) cost saving per patient in the IDgenetix(®) group. Incremental quality-adjusted life-year gain (0.49) and cost savings (US$6800) were substantially larger in patients with severe depression (Hamilton Rating Scale for Depression score ≥ 25). CONCLUSION: Using the IDgenetix(®) test to guide the treatment of patients with depression and anxiety may be a dominant strategy, as it improves quality-adjusted life-years and decreases overall costs over a 3-year time horizon.