Definition of pediatric hypertension: are blood pressure measurements on three separate occasions necessary?

The US Fourth Report (2004) recommended that elevated blood pressure (BP) on at least three occasions should be used to define hypertension in children and adolescents. However, there is no sufficient evidence to support this decision. This study aimed to assess the change in the prevalence of elevated BP obtained on three separate visits in children and adolescents worldwide using a meta-analysis. The PubMed database was searched for eligible studies published in English until 20 April 2016. Included studies were population based and reported on the prevalence of elevated BP measured on two or three separate occasions in pediatric populations. A meta-analysis was performed to calculate a summary prevalence of elevated BP over three different visits. A total of 21 studies with 179 561 participants aged 3-20 years were included in the present meta-analysis. The summary prevalence of elevated BP decreased across visits, from 12.1% (95% confidence interval (CI)=10.1-14.0%) during the first visit to 5.6% (95% CI=4.3-7.0%) during the second visit and to 2.7% (95% CI=2.1-3.3%) during the third visit. These findings were independent of sex, age group, ethnicity/race and the definition of elevated BP. When compared with visit 1, the prevalence of elevated BP decreased by 53.7% during visit 2 and by 77.7% during visit 3. Our study suggested that the prevalence of elevated BP decreased substantially from the first visit to the subsequent visits. Worldwide, the true prevalence of hypertension in children and adolescents is ~3% over three different visits.