Office blood pressure measurement alone often misclassifies treatment status in children with primary hypertension

Objective: Clinicians frequently rely on office blood pressure (BP) measurements alone to assess hypertension control, despite widespread acceptance of 24-h ambulatory blood pressure monitoring (ABPM) as the reference standard in the initial diagnosis of hypertension. This study was designed to investigate how often the hypertensive status differed between concurrent office BP versus ABPM measurements, and whether any patient-specific characteristics predict the risk for misclassification by office BP. Participants and methods: This study evaluated 42 children with primary hypertension who underwent repeated ambulatory monitoring (190 total recordings) with concurrent office BP measurement as part of their participation in n-of-1 trials. Results: In nearly 40% of the visits, the treatment status by office measurement was opposite to the status by ambulatory monitoring. Office BP underestimated the ambulatory hypertensive status (masked uncontrolled hypertension) in 25% of visits and overestimated ambulatory BP (white coat effect) in 14% of visits. The difference between office BP and ambulatory monitoring was consistent within patients across repeated visits. Patients whose office measurement underestimated or overestimated the ambulatory BP at the first visit were more likely to show persistent discrepancy at subsequent visits. Conclusion: The underuse of ambulatory monitoring in management decisions of children treated for primary hypertension may result in systematic misclassification of hypertension control.