Diagnostic value of strategy for the detection of white coat hypertension based on ambulatory and home blood pressure monitoring.

An algorithm has been proposed for the detection of white coat hypertension among subjects with elevated blood pressure (BP) on at least three clinic visits using home BP monitoring (screening test) and, if this is low, ambulatory BP monitoring (diagnostic test). This study aims to test this strategy in practice. The proposed algorithm was applied in 133 untreated subjects with elevated BP assessed in a previous prospective study using repeated clinic, home and ambulatory BP measurements. The proportions of detected and missed cases of white coat hypertension and the diagnostic value of the algorithm were calculated. By applying the algorithm, 99 subjects (74%) were found eligible for home measurements and 35 (26%) for ambulatory monitoring. There were 38 subjects with white coat hypertension (38%), of whom 15 (39%) were not detected by the proposed strategy. The sensitivity, specificity, and the positive and negative predictive value of the algorithm to diagnose white coat hypertension were 61, 81, 66 and 77%, respectively. Of the 34 subjects with normal BP on the third clinic visit, 15 (42%) had elevated home and/or ambulatory BP. These data suggest that, using the proposed strategy, many white coat hypertensives may remain undetected and may receive unnecessary long-term drug treatment. Therefore, more research is needed on the optimal strategy for detecting white coat hypertension in clinical practice.