Conway J
Department of Cardiovascular Medicine, Oxford, UK.
J Hypertens Suppl. 1991 Dec;9(3):S57-60.
Ambulatory blood pressure monitoring essentially estimates the average value of systolic and diastolic pressure from readings that fluctuate with mental and physical activity throughout the day. The improved reproducibility of blood pressure measurement achieved in this way increases the precision of clinical trials and/or reduces the number of subjects needed in a trial. Thus it is possible to detect a 5 mmHg diastolic difference between two treatments (with a statistical power of 0.9) using less than 20 subjects in a crossover trial. Ambulatory monitoring has its limitations. Since it is an averaging process, the ability to follow the effect of drugs over short periods of time is strictly limited. To overcome this handicap it is necessary to reduce the spontaneous variability of blood pressure, which can be done by limiting mental and physical activity while the drug action is being monitored. This can be achieved in the laboratory but not in freely moving subjects.
动态血压监测本质上是通过全天随精神和身体活动而波动的读数来估算收缩压和舒张压的平均值。以这种方式实现的血压测量重复性的提高，增加了临床试验的精度和/或减少了试验所需的受试者数量。因此，在交叉试验中使用少于20名受试者就有可能检测出两种治疗方法之间5 mmHg的舒张压差异（统计功效为0.9）。动态监测有其局限性。由于它是一个平均过程，在短时间内跟踪药物效果的能力受到严格限制。为克服这一障碍，有必要降低血压的自发变异性，这可以通过在监测药物作用时限制精神和身体活动来实现。这在实验室中可以做到，但在自由活动的受试者中则无法做到。
