Abstract
We referred to epidemiological data from Japan and abroad related to the development and progression of diabetic retinopathy, diabetic nephropathy, an diabetic neuropathy, ischemic heart disease, and cerebrovascular disease to design risk simulation software that, when patient background data and test results are entered, graphs the incidence rates of complications and lifetime medical costs and enables calculation of expected life years and quality-adjusted life years (QALYs). We constructed 6 submodels related to retinopathy, nephropathy, and neuropathy transitions and to coronary heart disease, stroke, and mortality based on epidemiological studies from Japan and abroad. Based on statistical data, including "National Healthcare Expenditures" and "Patient Surveys", and receipt surveys in healthcare institutions, we estimated the annual treatment costs that arise in each stage of the complications. In addition, we used a literature reference from abroad to set utility values in each stage of the complications in order to calculate QALYs. To validate our software for the progression of retinopathy we used the clinical data provided from 2 hospitals and we assessed how closely the retinopathy and nephropathy stage distribution 10 yr later predicted by our software and the actual disease stages matched. Although small discrepancies were seen from the absolute values, the results of the estimations related to the progression of retinopathy and nephropathy showed that the trends were very similar, and the estimates generally appeared to be valid. Our software makes it possible to perceive the effect on future health status and treatment costs visually by inputting the various test values before and after the intervention, and it seemed to be highly useful for evaluating medical support, patient education, and preventive measures, and for designing health policy.
