Sizing up hypertension in children
medwireNews: Blood pressure (BP) thresholds based purely on children's height allow physicians to identify those with hypertension, say researchers.
The team's table of thresholds based on actual height facilitated the diagnosis of hypertension in two different populations of children: one from Switzerland and one from the Seychelles.
"Simple user-friendly tools to identify children with elevated BP are needed by clinicians," say lead study author Arnaud Chiolero (University Hospital Center, Lausanne, Switzerland) and colleagues.
Current BP thresholds in children are based on age, gender, and height percentiles - the latter of which are often specific to certain countries or ethnicities. "These difficulties deter health professionals to assess elevated BP in children, threaten the validity of the BP assessment when it is done, and may lead to the underdiagnosis of hypertension in children," say the researchers.
Their table contains 11 absolute height categories, with 10 cm increments, and the BP thresholds for each category are derived from US age- and gender-specific percentiles. The table was highly sensitive and very highly specific for detecting hypertension (according to the US percentiles) among 5207 Swiss children, aged between 10 and 15 years, and 25,759 Seychellois children, aged from 4 to 19 years.
The sensitivities were 80% and 84% for the Swiss and Seychellois cohorts, respectively, and the specificity was 99% for both. The corresponding positive predictive values were 92% and 91% and the negative predictive values were 97% and 98%.
The proportions of Swiss and Seychellois children with hypertension were 10.0% and 8.4%, respectively, according to the table, and 11.4% and 9.1% based on the US percentiles.
Modifying the height table to be gender-specific did not significantly improve its performance, the researchers note in the Journal of Hypertension.
Chiolero et al note that tools such as smartphone applications and internet-based calculators could make it easier for physicians to use age- and gender-specific BP percentiles.
"Nevertheless, these tools require the proper electronic technology or being online at the time of the visit," they say. "A simple BP reference table may well become a preferred instrument for the screening in every day clinical practice for clinicians heavily constrained by time."
medwireNews (www.medwirenews.com) is an independent clinical news service provided by Springer Healthcare Limited. © Springer Healthcare Ltd; 2013
By Eleanor McDermid, Senior medwireNews Reporter