Analytical approach:
A decision analytic model was used to compare the cost-effectiveness of the two treatments, in a hypothetical cohort of 1,000 patients. The time horizon was two years. The authors stated that the perspective of the third-party payer was adopted.
Effectiveness data:
The estimates of treatment effectiveness were from two pivotal multicentre, randomised controlled trials of lacosamide versus placebo. The primary outcome was the proportion of patients with a reduction in seizure frequency, of at least 50%, compared with baseline seizure frequency. Adverse events were not included due to their low incidence with anti-epileptic drugs.
Monetary benefit and utility valuations:
The utility values were from an Italian study, which used the time trade-off technique to elicit utility values, from 81 patients with diagnosed uncontrolled epilepsy.
Measure of benefit:
The number of seizures avoided and quality-adjusted life-years (QALYs) were the summary benefit measures. Future QALYs were discounted at an annual rate of 1.5%.
Cost data:
The economic analysis considered the costs of drugs, practice nurse, general practitioner and out-patient department visits, in-patient and emergency department admissions, electroencephalograms, and laboratory tests. The resource use was the opinions of experienced neurologists in Belgium, collected using the Delphi panel technique. The costs were from Belgian national sources. They were in Euros (EUR) and discounted at an annual rate of 3%. The price year was 2008.
Analysis of uncertainty:
A deterministic univariate sensitivity analysis was undertaken on the key model inputs. These inputs were varied by ±10%, ±20% or ±30% from their initial values. A probabilistic sensitivity analysis, based on 1,000 Monte Carlo simulations, was performed. The types of probabilistic distribution were described. The results were displayed in a tornado diagram, and an incremental cost-effectiveness scatter plot.