2014 Volume 23 Issue 1 Pages 71-78
The risk chart of NIPPON DATA80 showing the absolute mortality from coronary heart disease (CHD) is the only chart of this type widely used in the medical field in Japan. In this chart, there are 240 frames for men with casual blood glucose of ≥200 mg/dL (the right side of the chart); these frames are separated according to smoking status, age, systolic blood pressure, and total cholesterol. The absolute CHD mortality during 10 years in these 240 frames ranges from <0.5% to ≥10% (more than 20 times difference). However, we estimated that there were only 5 CHD deaths at most in these 240 diabetic frames during the study period of NIPPON DATA80. The left (non-diabetic; another 240 frames) part of the chart was adopted for the Guidelines by Japan Atherosclerosis Society after excluding 60 frames for those in their 70s (180 frames as a whole), but those 180 frames were estimated to have only 35 CHD deaths despite the risk difference being more than 10. Furthermore, statistical values such as p value and confidence interval were not found either in the paper introducing the risk chart or in the referred paper for methodology. We, therefore, could not statistically estimate appropriateness of the risk chart. In conclusion, the NIPPON DATA80 risk chart for CHD mortality is not suitable for guidelines or education.
