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

Background: 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. Methods: 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. Results: 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). Conclusions: 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.