The Ningen Dock Medical Checkup is a unique medical checkup system conducted electronically in a Ningen Dock facility for the early detection and prevention of cancer and lifestyle-related diseases such as obesity, hypertension, lipid disorders and glucose metabolism disorders by risk management [1] . The detection of early stage lifestylerelated diseases requires a number of relevant clinical tests, and further requires a frame of reference to access these test results. Although this frame of

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... eference consists of the reference intervals (RIs), these RIs are often set for each medical checkup facility, even if the test results at different facilities are similar. Therefore, in order to provide highquality medical examinations uniformly throughout the country, it is necessary to set standardized RIs that could be adopted by all Ningen Dock facilities nationwide. Based on this way of thinking, we have now established new RIs for basic laboratory tests [2] . Especially in Japan where cerebrovascular disease is a prevalent cause of death and reduces healthy life expectancy, we also described the RIs for blood pressure (BP) that indicate cerebrovascular disease, and their use in preventive medicine. In addition, in the treatment of hypertension, the Japanese Society of Hypertension Guidelines for the Management of Hypertension (JSH 2019 Guidelines) show the classification of blood pressure and the procedure for treatment of hypertension [3] . These clinical decison limits (CDLs) and the RIs used for interpretation of the results of medical examinations are two different concepts and so should be used separately.