Author(s)

Kazumitsu Nawata¹, Moriyo Kimura²

¹Graduate School of Engineering, University of Tokyo, Tokyo, Japan.
²The Public Health Institute, Tokyo, Japan.

In this paper, we evaluate the difference between the first and second measurements of blood pressure (BP) when BP is measured twice using the results of 17,775 medical checkups. The two measurements for both systolic BP (SBP) and the diastolic BP (DBP) fluctuated a large amount even though they were measured at a short interval. The first measurements were 6.7 and 2.4 mmHg higher than the second ones for SBP and DBP, suggesting a white coat effect. Then, the factors that might affect the differences between the two measurements were analyzed by the regression models. For both SBP and DBP, the difference increased as the first measurement increased. Age, gender, BMI and alcohol consumption were other important factors affecting the difference. In the case of a typical male individual, the typical criteria for hypertension of 140/90, 160/100 and 180/110 mmHg criteria in the first measurement would correspond to 135/86, 150/94 and 165/102 mmHg in the second measurement. The necessity of developing accurate and cost-efficient BP measurement methods is strongly suggested.

Blood Pressure Measurement, Hypertension, White Coat Effect, Medical Checkup, Fluctuation of Blood Pressure

Nawata, K. and Kimura, M. (2017) Reliability of Blood Pressure Measurements: An Analysis of the White Coat Effect and Its Fluctuations. Health, 9, 506-519. doi: 10.4236/health.2017.93036.