[Cost-utility analysis of two formulations of botulinum toxin type A in the treatment of blepharospasm and cervical dystonia in Spain].

[INTRODUCTION] Studies on focal dystonia showed that the formulations of botulinum toxin type A, incobotulinumtoxin-A (Inco-BTA) and onabotulinumtoxin-A (Ona-BTA), have equivalent efficacy and safety.

[AIM] To carry-out a cost-utility analysis of Inco-BTA administered on flexible intervals vs. Ona-BTA on a fixed interval, in the treatment of blepharospasm and cervical dystonia.

[PATIENTS AND METHODS] A probabilistic Markov model was designed to estimate costs (euros, 2017) and benefits (quality-adjusted life years, QALY), from the Spanish National Health Service perspective and on a 5-year time horizon, of treatment of blepharospasm and cervical dystonia with Inco-BTA (6-12 month flexible intervals) versus Ona-BTA (12-month fixed intervals). It is assumed that symptoms will re-emerge some time later in both options. Result was expressed as incremental cost-utility ratio (ICUR).

[RESULTS] Inco-BTA and Ona-BTA costs were 3,742 and 3,366 euros respectively, in blepharospasm, and 6,673 and 6,419 euros in cervical dystonia. Patients treated with Inco-BTA remained asymptomatic for 22.12, and 21.34 more weeks than those treated with Ona-BTA, leading in 3.040 and 3.012 QALY, respectively, in blepharospasm, and 3.471 and 3.401 QALY, respectively, in cervical dystonia. Differences showed statistical significance in all cases. ICUR was estimated as 13,576 and 4,158 euros/QALY in blepharospasm and cervical dystonia, respectively.

[CONCLUSIONS] Treatment of blepharospasm and cervical dystonia with Inco-BTA is a cost-effective therapeutic alternative in Spain, based on the flexibility of their administration.