Self blood pressure monitoring: a worthy substitute for ambulatory blood pressure?

The European Society of Hypertension (ESH), the American Heart Association (AHA) and the American Society of Hypertension (ASH) have published guidelines for self-monitoring of blood pressure (SBPM). We aimed to demonstrate the equivalence of SBPM with ambulatory blood pressure monitoring (ABPM) in the assessment of hypertension. A total of 87 consecutive subjects referred from primary care for standard ABPM underwent a 1-week period of SBPM, as defined by the ESH guidelines, either before or after ABPM. There was no difference in mean blood pressure (BP): SBPM 142/87 mm Hg, daytime average ABPM 141/86 mm Hg. The intra-class correlation coefficient was 0.72 and 0.89 for systolic and diastolic pressure, respectively. SBPM is concordant with ABPM in classifying subjects as hypertensive or normotensive in 87% of cases (κ=0.56). The coefficient of variation of SBPM compared with ABPM was 5%. In answer to a direct question 81% of subjects preferred SBPM to ABPM. The current self-monitoring schedule recommended by the ESH, AHA and ASH is valid. The mean BP obtained from SBPM is equivalent to awake-time BP on ABPM, the accepted reference standard for ‘out of office’ BP measurement. SBPM is simpler to carry out, preferred by patients and should be considered on a par with ABPM.