PRM149 - OPEN-SOURCE DISCRETE EVENT SIMULATION MODEL FOR MAJOR DEPRESSION DISORDER (MDD): AN UPDATE SUITABLE FOR NEW GENERATION TREATMENT?

Abstract

In 2014, an open-source discrete event simulations (DES) model was developed for major depressive disorder (MDD) to estimate health and cost outcomes associated with alternative treatment strategies. The DES has been updated in order to provide a freely available up-to-date cost-effectiveness analysis taking into account potential gene therapy. This model simulated short-and long term clinical events (partial response, remission, relapse, recovery, and recurrence), adverse events, and treatment changes (titration change, switch, addition, and discontinuation) over up to 5 years. Several treatment pathways were defined by clinical experts considering classical therapy and gene therapy with three levels of efficacy, tolerability, and price (low, medium and high) from first line to third line. The possibility of a one-time cost was implemented and the model was updated with input data from the literature for the UK settings. Model outputs include time in different health states, quality adjusted life years (QALYs) and costs from National Health Service and societal perspectives. The model remains open source and is now available on GitHub. The largest cost components from the payer perspective were the price of the new drug followed by physician visits and hospitalisations. The predicted costs and QALYs were driven by utility values, effectiveness, and frequency of physician visits. Differences in QALYs and costs between strategies were dependent with the duration of the simulation: a shorter time horizon limited the capture of the long term health benefit, increasing the impact of the high one time-cost on the ICER. The discrete event simulation model can provide a comprehensive evaluation of different therapeutic options in MDD including potential gene therapy and can be used to compare a wide range of health care technologies in various groups of patients in MDD. The fact that the DES is open-source reinforced the credibility and the acceptability of the model.