Analytical approach:
A probabilistic decision model was used to compare the effectiveness and costs of the two treatment options. The time horizon of the analysis was 12 years. The authors reported that the perspective was that of the UK National Health Service (NHS).
Effectiveness data:
The effectiveness data were derived from a published multi-centre retrospective cohort study. The details of the study were adequately reported. The main clinical parameters included the probability of technical failure of the UAE, general adverse events associated with UAE, intervention-related complications, and additional procedures necessary in the case of incomplete fibroid treatment.
Monetary benefit and utility valuations:
The utility values were obtained from a published randomised controlled trial which compared UAE with hysterectomy. In that trial, the patients’ utilities were evaluated using the European Quality of life (EQ-5D) questionnaire.
Measure of benefit:
The authors used quality-adjusted life-years (QALYs) as the measure of benefit. They were discounted at an annual rate of 3.5%.
Cost data:
The cost categories included the costs of the surgical interventions, complications, and additional procedures. The unit costs and resource quantities were reported separately and in great detail. The cost data were mainly obtained from a previous study and from a national official source (NHS reference costs), while expert clinical opinion was used when no UK data were available. For complications, the weighted average costs were computed by the authors. All costs were in UK pounds sterling (£), were reported for the price year 2004, and were discounted at an annual rate of 3.5%.
Analysis of uncertainty:
The authors conducted various one-way sensitivity analyses to investigate the structural uncertainty in their model. They tested three assumptions: firstly, that the quality of life was greater with an intact uterus after UAE, than with complete uterus removal in hysterectomy; secondly, that UAE was provided in women aged 30 years; and thirdly, the inclusion of productivity losses, due to treatment, using the human capital approach. In addition, a probabilistic sensitivity analysis was conducted, while the influential parameters were further investigated using an analysis of covariance.