Ambulatory and home blood pressure measurement: complementary rather than competitive methods.

Clinic (office) blood pressure (BP) measurement has a well-established role in medical practice and is the standard on which most of the literature is based. However, clinic BP has several important limitations, including the potential for inadequate or misleading estimates of a patient’s true BP status and suboptimal prediction of cardiovascular risk. Particularly relevant is the concern that clinic BP measured with standard techniques may not provide a representative estimate of an individual’s usual BP outside the medical setting. Out-of-office BP assessment takes 2 forms at the present time, self (or home) BP measurement (SBPM) and ambulatory BP monitoring (ABPM). These 2 techniques have attracted considerable attention in recent years because of the potential for better classification of hypertensive status compared with office BP. SBPM devices allow for repeated measurements outside the medical environment, and their use has been recommended by several international guidelines.1,2 ABPM is currently considered the gold standard for the correct diagnosis of hypertension on the grounds that the ambulatory BP provides extensive information on several BP parameters other than the average BP, including BP variability, the morning BP surge, BP load, and the nocturnal fall in BP.3 However, it should be noted that all of the clinical guidelines still focus on the importance of the mean ambulatory BP for clinical practice, and all of the other parameters are still considered experimental. ABPM is not widely available in primary care practice and is considered most helpful when self-measured BP is within borderline values. According to most authorities, self-BP measurement should be used as an initial step to evaluate the out-of-office BP1–3 and, thus, used as a screening procedure that should lead to an ABPM for confirmation. However, it is not well known whether this strategy is appropriate because ambulatory BP and self-measured BP may provide different and complementary clinic information. Indeed, several studies have shown that these 2 measures do not have a high correlation4 and that disagreement in the diagnosis of hypertension between the 2 methods is not uncommon