This evaluation was based on a single study (Sullivan, et al. 2007, see ‘Other Publications of Related Interest’ below for bibliographic details). The costs and effects were analysed over a nine-month period using a decision analytic model. The authors stated that the study perspective was that of the British National Health Service (NHS).
The data on effectiveness in terms of the percentage of patients with "complete recovery of facial function” were derived from a multi-centre, double-blind, placebo-controlled randomised factorial study. Other outcomes were quality of life, pain, appearance, costs and efficiency. Multivariate regression analyses were used to adjust for baseline covariates.
Monetary benefit and utility valuations:
The utility weights were measured by the Health Utilities Index mark III (HUI III) at three, six and nine months. An analysis of covariance was used to obtain the weights, for cured and non-cured participants at three and nine months, which were adjusted for baseline utility scores.
Measure of benefit:
The two measures of benefit were quality-adjusted life-years (QALYs) and the percentage of cured cases.
The cost types were those of initial treatments (drugs) and follow-up (hospital-based and primary-care services). Measurement of the quantities of resources was based on a sub-sample of 74 trial participants. UK unit costs were applied to the medications using the British National Formulary, while follow-up costs were derived from publicly-available sources (Curtis, et al. 2006, see 'Other Publications of Related Interest' below for bibliographic details). The cumulative mean costs were estimated for cured and non-cured patients and ordinary least-squared regressions were applied. The costs were reported in 2006 to 2007 UK pounds sterling (£).
Analysis of uncertainty:
Deterministic and probabilistic sensitivity analyses were performed to assess the parameter uncertainty. Monte Carlo simulations with 1,000 iterations were conducted and cost-effectiveness acceptability curves were plotted using a range of willingness-to-pay thresholds from £10,000 to £50,000 per QALY gained. One-way and threshold analyses were also undertaken on the key parameters.