Comparison of auscultatory and oscillometric BP measurements in children with obesity and their effect on the diagnosis of arterial hypertension.

OBJECTIVE

The level of agreement between two blood pressure (BP) reading methods, auscultatory vs oscillometric, was examined using a mercury sphygmomanometer and an electronic device in children and adolescents with different levels of obesity. The readings were compared to determine their impact on the diagnosis of pre-hypertension/hypertension.

METHODS

Blood pressure readings were taken in children with obesity (body mass index ≥ 95th percentile) and severe obesity (≥120% 95th percentile). Bland-Altman analysis and Intraclass Correlation Coefficient were used to determine the agreement between measurements.

RESULTS

The mercury sphygmomanometer readings were lower than those obtained with the electronic device for both systolic and diastolic BP (P=.01 and P=.001, respectively). The mean systolic and diastolic BP differences between the oscillometric vs first mercury reading were 4.2/10.2mmHg, respectively. A large difference was observed between the BP measurement methods. The ICC showed regular to moderate reliability for the systolic BP (.595), but poor for the diastolic BP (.330). Screening using the first of three mercury measurements showed that 10.4% of the children and adolescents had BPs within the pre-hypertension/hypertension range. This was reduced to 5.2% when the mean of three mercury readings was used.

CONCLUSIONS

Large discrepancies were observed in both the systolic and diastolic BP. These differences are not clinically acceptable as to consider the two instruments interchangeable. The electronic device readings were higher, and they overestimated the diagnosis of hypertension.