Analytical approach:
The economic evaluation was based on a Markov model of the natural history of the condition and the impact of treatment on that progression. A 25-year time horizon was used. The authors stated that the perspective of the UK NHS was adopted.
Effectiveness data:
A review was carried out in the MEDLINE database to identify randomised controlled trials (RCTs) and well-constructed observational studies, included from May 1999 to May 2009. A manual search of references and abstracts was performed. The authors selected the most appropriate study for each model input, including oesophagectomy complications, progression to adenocarcinoma after oesophagectomy, progression during surveillance following ablation, and mortality data. Radiofrequency ablation complications and outcomes after ablation were from both the wider ablative therapy literature and authors' assumptions. Six-monthly transition probabilities were derived.
Monetary benefit and utility valuations:
The utility values were from published studies that used the standard gamble method.
Measure of benefit:
Quality-adjusted life-years (QALYs) were the summary benefit measure. Life-years were also presented. Both measures were discounted at an annual rate of 3.5%.
Cost data:
The economic analysis included the costs of surgical procedures, including surgical complications, routine endoscopy, and biopsies; follow-up out-patient visits; and the palliation of untreatable adenocarcinoma. These costs were mainly based on NHS reference costs. All costs were in UK pounds sterling (£) and were discounted at an annual rate of 3.5%. The price year was 2010.
Analysis of uncertainty:
Univariate sensitivity and threshold analyses were carried out on a range of key model inputs. A probabilistic sensitivity analysis, based on a second-order Monte Carlo simulation, was undertaken using predetermined probability distributions for the model inputs.