Height-Based Equations Can Improve the Diagnosis of Elevated Blood Pressure in Children.

Abstract

High blood pressure (BP) is usually underdiagnosed in children and adolescents, particularly due to its complex diagnosis process. This study describes novel height-based equations for the detection of BP disorders (BP > 90th percentile) and compares the accuracy of this approach with previously described screening methods to identify BP disorders. Height-based equations were built using the 90th percentile values for systolic and diastolic BP and respective height values from the current guideline of high-BP management in children. This guideline was also used as the gold standard method for identification of BP disorders. The equations were tested in Brazilian (n = 2,936) and American (n = 6,541) populations of children with 8-13 years old. The obtained equations were 70 + 0.3 × height (in cm) for systolic BP and 35 + 0.25 × height (in cm) for diastolic BP. The new equations presented sensitivity and negative predictive value of near 100% and specificity > 91% and showed higher specificity and positive predictive value when compared with other screening tools. Importantly, height-based equations had greater agreement (kappa coefficient = 0.75-0.81) with the gold standard method than the other methods (kappa coefficient = 0.53-0.73). Further analysis showed that alternative height-based equations designed to identify hypertension (BP ≥ 95th percentile) also showed superior performance (kappa coefficient = 0.89-0.92) compared with other screening methods (kappa coefficient = 0.43-0.85). These findings suggest that the use of height-based equations may be a simple and feasible approach to improve the detection of high BP in the pediatric population.