Cost-effectiveness of abobotulinumtoxinA plus best supportive care compared with best supportive care alone for early treatment of adult lower limb spasticity following an acute event.

Abstract

Spasticity is an incurable chronic condition, and patients with spasticity frequently experience symptoms such as muscle stiffness, restricted mobility, fatigue, spasms, and pain. The study objective was to assess the cost-effectiveness of abobotulinumtoxinA plus best supportive care compared with best supportive care alone for the early treatment of adult lower limb spasticity following an acute event (e.g. stroke or traumatic brain injury), from an Australian payer perspective. Using clinical data from published pivotal trials, an economic model based on a Markov model was developed to capture changes in treatment costs, healthcare resource use costs, functional outcomes, and health-related quality of life over a lifetime horizon. Scenario analyses and a probabilistic sensitivity analysis were conducted to explore the uncertainty in the model parameters and assumptions used in the base case. AbobotulinumtoxinA plus best supportive care was cost-effective versus best supportive care, yielding an incremental cost-effectiveness ratio of $35,721 per quality-adjusted life year gained. Sensitivity analyses confirm the robustness of the base case, with most results remaining below the commonly acceptable cost-effectiveness willingness-to-pay threshold of $75,000 per quality-adjusted life year for cost-effectiveness in Australia. Inputs and assumptions that produced the top four highest incremental cost-effectiveness ratios include the application of different health resource utilisation source, short time horizon, unweighted regression analyses to determine regression probabilities, and no stopping rule. AbobotulinumtoxinA plus best supportive care has a 74% probability of being cost-effective compared with best supportive care alone at the willingness to pay threshold. AbobotulinumtoxinA plus best supportive care treatment is cost-effective in Australia for the management of adult lower limb spasticity in patients treated within 2 years of an acute event.