Diagnosis of hypertension using home or ambulatory blood pressure monitoring: comparison with the conventional strategy based on repeated clinic blood pressure measurements

The objective of the study was to investigate whether measurement of blood pressure at home (HBP) or by ambulatory monitoring (ABP) are reliable alternatives to the traditional strategy for hypertension diagnosis based on blood pressure measurement on repeated clinic visits (CBP). A total of 133 untreated subjects with diastolic CBP 90–115 mmHg on the initial visit were evaluated with HBP (6 workdays), ABP monitoring (2 occasions) and CBP (5 visits within 3 months). The diagnostic value of the HBP and the ABP method was compared to the conventional CBP strategy. Hypertension was diagnosed in 57%, 54% and 45% of subjects using the CBP, ABP and HBP methods respectively (p=NS). Agreement in the diagnosis of hypertension between all three methods was found in 59% of cases. Disagreement between CBP/ABP was found in 27%, CBP/HBP in 28% and ABP/HBP in 28% of cases. The sensitivity, specificity, positive and negative predictive value of ABP to diagnose hypertension correctly were 73%, 73%, 79% and 66% respectively and of HBP 64%, 84%, 85% and 62%. The above parameters for HBP compared to ABP in the detection of white coat hypertension were 67%, 87%, 50% and 93% respectively. These data suggest that indiscriminate use of HBP or ABP monitoring in the evaluation of all subjects with high blood pressure will probably result in confusion and therefore should be discouraged. However, in the detection of white coat hypertension, HBP appears to be useful as a screening test, which, if positive, requires confirmation with ABP monitoring.