The cost-effectiveness of open or thoracoscopic thymectomy compared to medical treatment in managing Myasthenia gravis without thymomas.

Objective: Assessing the cost-effectiveness of open or thoracoscopic thymectomy compared to medical therapy in managing myasthenia gravis not associated with thymoma.
Methods: A Markov model was designed for evaluating three strategies' cost-effectiveness. Transition probabilities were taken from the pertinent literature; the costs were estimated from official tariff manuals. Incremental cost-effectiveness ratios were estimated and probabilistic and deterministic sensitivity analysis was used for clinical variables, costs and the model's assumptions.
Results: Thoracoscopic thymectomy was the most effective and least costly strategy and dominated the other two alternatives. The cost per life year gained was Col $ 1 129 531 without discount and Col $ 805 179 with discount. Univariate sensitivity analysis showed that the main variables affecting the results were the effects' discount rate, the cost of a myasthenic crisis and the probability of complete remission. Thoracoscopy thymectomy was the most cost-effective strategy for different thresholds of willingness to pay in probabilistic analysis.
Conclusions: Thoracoscopic thymectomy is a cost-effective strategy in the treatment of MG without thymoma.