The analysis was based on a published Markov model, with a lifetime horizon, and a hypothetical cohort of 50-year-old patients who were newly diagnosed with type 2 diabetes. The authors stated that the perspective of the health care system was adopted.
Literature reviews were carried out to identify the relevant sources for the clinical inputs. Databases such as PubMed were searched. The efficacy of treatment was a key input and was pooled data from two published meta-analyses. Other transition probabilities were from clinical trials. Mortality was from Dutch national databases. The distribution of patients among health states was based on a Finnish study; other epidemiological data were generally from Dutch publications and databases.
Monetary benefit and utility valuations:
The utility values were from published sources, including a cross-sectional study of 292 patients and a systematic review of empirical studies. Both sources used the time trade-off questionnaire.
Measure of benefit:
Quality-adjusted life-years (QALYs) were the summary benefit measure and they were discounted at an annual rate of 1.5%. Undiscounted life-years were reported.
The economic analysis included the costs of the ACE inhibitors, ARBs, screening procedures, treatment for end-stage renal disease (ESRD), and general expenditure for diabetes and other health care. The most frequently prescribed ACE inhibitor (enalapril) and ARB (irbesartan) in the Netherlands were considered. The drug costs were based on official Dutch prices, including value-added tax (VAT) and pharmacists’ prescription fees. The costs of screening were based on recommended prices. The annual cost of ESRD was from a Dutch study. All costs were in Euros (EUR) and the price year was 2010. A 4% annual discount rate was applied.
Analysis of uncertainty:
One-way sensitivity analyses were carried out, using confidence intervals where available. A Monte Carlo simulation was performed, using conventional probability distributions for the model inputs. The net monetary benefit was calculated and cost-effectiveness acceptability curves were plotted.