The performance of modified blood pressure-to-height ratio as a screening measure for identifying children with hypertension

Objectives: This study evaluated the accuracy of modified blood pressure-to-height ratio (MBPHR) for identifying hypertension in Han children aged 7-12 years. Methods: In 2011, anthropometric measurements were assessed in a cross-sectional population-based study of 1352 Han children aged 7-12 years. Elevated blood pressure was defined according to the 2004 National High Blood Pressure Education Program Working Group definition (as gold standard). The following equations for MBPHR were used: modified systolic blood pressure to height ratio(MSBPHR) = SBP(mmHg)/(height(cm) + 7 x (13 - age(years))), modified diastolic blood pressure to height ratio (MDBPHR) = DBP(mmHg)/(height(cm) + 7 x (13 - age(years))). Receiver operating characteristic curve analyses were performed to assess the accuracy of MSBPHR and MDBPHR as diagnostic tests for elevated SBP and DBP, respectively. Results: The accuracy of MSBPHR and MDBPHR (assessed by area under the curve) for identifying elevated SBP and DBP were over 0.85 (0.953-1.000). When elevated blood pressure was defined by MBPHR (age-dependent cut-off point), the sensitivities were 99.1% in boys and 97.0% in girls and the specificities were 89.0% in boys and 92.3% in girls. When elevated blood pressure was defined by MBPHR (non-age-dependent cut-off point), the sensitivities were 96.4% in boys and 99.2% in girls and the specificities were 81.2% in boys and 75.5% in girls. Conclusions: MBPHR is an accurate index for screening hypertension in children, but is not superior to BPHR. Compared with age-dependent BPHR cutoff points, non-age-dependent MBPHR cut-off point is simple but increase the proportion of reexamination.