Evaluating Treatment Sequences in Major Depressive Disorder Using an Open-Source Health Economic Model Based on...

This study developed a patient-level discrete event simulation model to assess value of treatment sequences for newly diagnosed adult patients with major depressive disorder.

Model specifications were informed by a continual stakeholder and patient engagement approach, literature, and key findings from claims analysis. Key model outputs included time to response, remission rates, net monetary benefit, and cost-effectiveness. This open-source model attempts to capture the patient journey by modeling treatment pathways (vs individual treatments), periods with no treatment, and patient heterogeneity.

The base-case analysis evaluates key outcomes from 5 treatment pathways over 5 years. Results show that all sequences of solo or combination treatments are superior to no treatment in terms of total quality-adjusted life-years (QALYs) accrued and net monetary benefit. Treatment with selective serotonin reuptake inhibitors (SSRI) across all 4 lines of therapy dominated no treatment. Treatment with SSRI as the first line, followed by serotonin-norepinephrine reuptake inhibitors (SNRI) as the second line, SNRI plus atypical antidepressant as the third line, and SNRI plus antipsychotic as the fourth line resulted in higher costs but also higher QALYs relative to 4 lines of SSRI, with an incremental cost-effectiveness ratio of approximately $28 000/QALY. In contrast, SSRI first-line treatment followed by SSRI plus intensive psychotherapy for second through fourth lines were not found to be cost-effective because of small QALY gains and high cost owing to the number of psychotherapy sessions modeled here.

Understanding drivers of effective treatment across diverse patient journeys is crucial to optimizing care. This model offers insights into relative value of treatment strategies aligned with real-world experiences, supporting more informed decision making and improved outcomes.