Cost-effectiveness of coronary artery disease screening in asymptomatic patients with type 2 diabetes and other atherogenic risk factors in Japan: factors influencing on international application of evidence-based guidelines.

BACKGROUND: Screening for coronary artery disease (CAD) in asymptomatic diabetic patients with atherogenic risk factors is recommended by the American College of Cardiology/American Diabetes Association. It is not clear whether these guidelines apply to the Japanese population with a different epidemiology of CAD. This study evaluates the applicability of the U.S. guidelines to Japan, taking account of cost-effectiveness.

DESIGN: A cost-effectiveness analysis using a Markov model was performed to measure the clinical benefit and cost of CAD screening in asymptomatic patients with diabetes and additional atherogenic risk factors. We evaluated cohorts of patients stratified by age, gender, and atherogenic risks. The incremental cost-effectiveness of not screening, exercise electrocardiography, exercise echocardiography, and exercise single-photon emission-tomography (SPECT) was calculated. The data used were obtained from the literature. Outcomes are expressed as US dollars per quality-adjusted life year (QALY).

RESULTS: Compared with not screening, the incremental cost-effectiveness ratio (ICER) of exercise electrocardiography was $31,400/QALY for 60-year-old asymptomatic diabetic men, and 46,600 for 65-year-old women with hypertension and smoking. The ICER of exercise echocardiography was $31,500/QALY and of SPECT was $326,000/QALY, compared with the next dominant strategy. Sensitivity analyses found that these results varied according to age, gender, the combination of additional atherogenic risk factors, and the frequency of screening.

CONCLUSION: From a societal perspective the U.S. guidelines on screening for CAD in high risk diabetic patients are applicable to the Japanese population. However, the population subjected to screening should be carefully selected to obtain greatest benefit from screening.