Analytical approach:
The analysis was based on a Markov model with a five-year and a lifetime (25-year) horizon. The authors stated that the perspective of the public health care payer was adopted.
Effectiveness data:
The clinical data were selected by the authors. The baseline risk and natural history of the disease were based on the UK Prospective Diabetes Study (UKPDS). The relative risk reduction in cardiovascular events with atorvastatin was the key model input. This and the adherence rate were from the Collaborative Atorvastatin Diabetes Study (CARDS), a randomised controlled trial with a 3.9-year mean follow-up (Colhoun, et al. 2004, see ‘Other Publications of Related Interest' below for bibliographic details). National statistics were used for the age-specific mortality data and a Belgian source (the Optimize Cardiovascular Prevention in Diabetes, OCAPI, survey) was used to define the patient cohort. Other data were from published studies.
Monetary benefit and utility valuations:
The utility values were from a published study that used the time trade-off method.
Measure of benefit:
Quality-adjusted life-years (QALYs), disease-free life-years (DFLYs), and life-years were the summary benefit measures. A 1.5% annual discount rate was applied.
Cost data:
The two main cost categories were: the (short-term) acute phase and the (long-term) medical follow-up, and these included hospital stay and procedures. These costs were from the hospital database of the Public Health Authorities as well as from published studies. The cost of atorvastatin was based on official prices and considered the decreases imposed by Belgian legislation over a drug's life cycle and the introduction of a generic after expiry of the drug patent. The costs were in Euros (EUR) and the price year was 2009. A 3% annual discount rate was applied.
Analysis of uncertainty:
A probabilistic sensitivity analysis was undertaken, by assigning beta distributions to the clinical inputs and gamma distributions to the cost inputs. A deterministic one-way sensitivity analysis was undertaken on the health care costs for cardiovascular disease, focusing on the follow-up costs.