To assess the cost-effectiveness sand the budgetary impact of the combination of botulinum toxin (BT) + conventional treatment (CT) (hormonal treatments + analgesics) compared with CT alone in patients suffering from severe dysmenorrhoea, using a Markov model.

A Markov model was developed to estimate, from the perspective of French Health Insurance (HI), the cost effectiveness and the budgetary impact of BT+CT compared with CT alone. The main health states in the model were based on Visual Analogue Scale (VAS) scores and expert opinion. All model parameters were derived from a cohort of patients treated for 12 months at the Centre de Recherche de la Santé et de la Femme (CRSF) for severe dysmenorrhoea in 2021. A Cost-Utility Analysis (CUA) was carried out to assess the quality of life of patients, crucial in this context, in which the direct healthcare costs were considered in and Budget Impact Analysis (BIA). The main decision-making criteria were the Incremental Cost-Utility Ratio (ICUR) for the CUA and the net impact for the BIA. Deterministic and probabilistic univariate sensitivity analyses were performed to assess the robustness of our results.

Over the 1-year time horizon (main analysis), the costs and quality-adjusted life year (QALY) of BT+CT versus CT alone were equal to €1895.65 vs €3055.20 and 2.03 QALYs vs 1.23 QALYs, respectively. Consequently, the ICUR equalled -€1651.5/QALY, which shows that, although the initial costs of BT are higher than those of CT, the reduced follow-up costs associated with the long-term efficacy of BT make it the most effective and economically dominant option at 1, 5 and 10 years. Sensitivity analyses show that 100% of Monte Carlo iterations are below the willingness-to-pay threshold of €30,000¹/QALY, making BT+CT an efficient strategy that could be adopted and reimbursed.

In the absence of a reference treatment for the management of severe dysmenorrhoea, BT+CT offering an improvement in quality of life, as well as a reduction in follow-up costs. It is therefore the most cost-effective strategy over 10 years.