MEASURING PATIENT BENEFIT FROM BOTULINUM TOXIN IN THE TREATMENT OF DYSTONIA - FEASIBILITY OF COST-UTILITY ANALYSIS

The dystonias are a group of movement disorders arising from CNS dysfu nction and characterised by involuntary and prolonged spasms of muscle contraction. Recently there has been increasing demand for treatment with botulinum toxin (BT), a relatively expensive neurological paralyt ic agent. As there has been no systematic assessment of patient benefi t from BT, this study was undertaken to develop and test a methodology for assessing the cost utility of BT therapy for patients with dyston ias. A generic health status instrument, the EuroQOL, was completed at regular intervals over at least 6 months by 130 patients with a curre nt diagnosis of dystonia. A general population tariff was used to calc ulate quality-adjusted life-year (QALY) gains from BT treatment, and r elevant cost data were obtained from patients and medical records. The cost-per-QALY estimates ranged considerably, depending on the type of dystonia, the duration of BT treatment, type of health-related qualit y-of-life (HR-QOL) tariff used and baseline characteristics of partici pants. The study findings reflect the general clinical impression of B T: that it can benefit patients with dystonia, but the benefit may be small compared with many treatments for other diseases. The nature of the disease and its cyclical treatment caused practical difficulties i n recruiting participants, administering questionnaires and in estimat ing QALY gains.