There are four accepted methods to measure BP: routine office BP (ROBP) measurement, automated office BP (AOBP) measurement, home BP measurement (HBPM), and ambulatory BP measurement (ABPM). The first 2 methods are performed in the clinic setting, while the latter 2 outside of clinics. ROBP was the most commonly performed, and a vast majority of CV outcome trials were based on ROBP to modify medications or treatment strategies. However, ROBP was less precise as only 1 or 2 BP measurements were obtained, and many factors affected the accuracy of readings. One of the major concern with ROBP is the alerting response which causes the white coat phenomena seen as white coat hypertension in non-hypertensives and white coat effect in known hypertensives. More importantly, the accuracy of ROBP is especially a great concern in the crowded clinics in most of the regions in Taiwan. AOBP improves some drawbacks of ROBP. Though AOBP is also performed in clinical setting, it requires automated oscillometric devices with multiple readings, an averaged reading that can be stored, and an attended or un-attended quiet space. The recent SPRINT trial used AOBP to enroll and follow up hypertensive patients, and used the readings of AOBP as BP targets. AOBP is difficult to apply to the clinical settings in Taiwan as most of hospitals and clinics cannot afford to have extra isolated spaces.
　　Out-of-office BP measurements include HBPM and ABPM. HBPM is referred to measurements of BP at home usually by oneself, or on occasion, by caregivers or research assistants. Compared to ROBP, HBPM is more likely to be free of environmental and/or emotional stress (such as white-coat effect). HBPM is better than ROBP for the prediction of hypertension-mediated organ damage (HMOD) and cardiovascular outcomes. In a systemic review of 9 publications, HBPM was non-inferior to ABPM in predicting CV events and mortality. Four Asian studies have demonstrated that morning home BP is a better prognostic predictor of CV events than ROBP. In the 2022 HT guidelines of Taiwan Society of Cardiology/Taiwan Hypertension Society, HBPM is advocated in the diagnosis and management of hypertension in Taiwan.
Definition and grading of hypertension: