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

• Published in: American journal of hypertension Vol. 31; no. 9; pp. 1059 - 1065
• Main Authors: Mourato, Felipe A, Mattos, Sandra S, Lima Filho, Jose L, Mourato, Marianna F, Nadruz, Wilson
• Format: Journal Article
• Language: English
• Published: US Oxford University Press 03-08-2018
• Subjects: blood pressure; diagnosis; screening; hypertension; pediatrics; height
• DOI: 10.1093/ajh/hpy028
• EISSN: 1941-7225
• ISSN: 0895-7061

Abstract
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.