Is one measurement enough to evaluate blood pressure among adolescents? A blood pressure screening experience in more than 9000 children with a subset comparison of auscultatory to mercury measurements.

Evaluation of blood pressure is recommended in all children older than 3 years. Auscultatory devices are the recommended method to assess blood pressure in pediatrics, but automated oscillometric devices are increasingly common. A retrospective analysis of our school-based blood pressure screening was performed to determine if multiple oscillometric blood pressure measurements are needed to approach true blood pressure. All children had 4 oscillometric measurements of blood pressures and a random subset of 287 had an additional auscultatory measurement. Among 9870 participants, we observed a nonlinear decrease in blood pressure over time. The largest decrease in systolic blood pressure was between first and second (-3.8 mm Hg) and in diastolic from second to third (-3.3 mm Hg) measurement. For systolic blood pressure, the second oscillometric measurement, the average of second to third and the average of first to third were statistically similar to a single auscultatory measurement. We conclude that assessment of blood pressure using oscillometric devices should include at least 3 measurements in the same sitting to avoid inaccurate assessment.