Analytical approach:
The analysis was based on a published and validated computer simulation model of diabetes, the Center for Outcomes Research (CORE) model, with a 30-year time horizon. The authors stated that a societal perspective was adopted.
Effectiveness data:
It appeared that a selective approach was used to identify relevant sources of evidence for the model. Most data related to the efficacy of insulin treatment compared to IGIa were taken from the Korean cohort (87 patients) of the PREDICTIVE study (a large observational study based on everyday clinical practice). Additional estimates were taken from other country-specific sources. Most data for transition probabilities were taken from clinical trials and epidemiological studies conducted in Western countries. Changes in HbA1c level with the two regimens was the primary input and was taken from the PREDICTIVE study.
Monetary benefit and utility valuations:
Utility valuations were taken from a published study that referred to the CORE model.
Measure of benefit:
Life-years and quality-adjusted life-years (QALYs) were used as the summary benefit measures and were discounted at an annual rate of 3%.
Cost data:
The economic analysis included the costs associated with patients' management and diabetes complications. Costs of patient time and travel expenses were included. Resource quantities were based mainly on authors’ opinions and some published studies. Costs were taken from local sources supplemented by data from countries in the same Asian region. Travel costs were based on the Survey of health care for elderly people in Thailand. Costs were in US dollars ($). A discount rate of 3% was applied. The price year was 2010.
Analysis of uncertainty:
One-way sensitivity analyses were carried out to consider the impact of variations in time horizon, discount rate, hypoglycaemic event rate, body mass index and reduction in the HbA1c level. A non-parametric bootstrapping approach was used to generate mean and standard deviation values.