Prevalence and Screening of Hypertension Among Schoolchildren in Phitsanulok, Lower Northern Thailand

Objective: To identify the prevalence of hypertension among children living in Phitsanulok, lower northern Thailand, and to compare blood pressure (BP) equal or greater than 120/80 mmHg screening with the American Academy of Pediatrics (AAP) 2017 diagnostic criteria for hypertension. Materials and Methods: A retrospective cross-sectional study was conducted among primary schoolchildren in Phitsanulok between February 2014 and August 2016. Elevated BP and hypertension were determined using the AAP 2017 diagnostic criteria. Data were analyzed for frequency, mean, and diagnostic test performance comparing BP equal or greater than 120/80 mmHg screening with the reference test. Results: One thousand four hundred thirty-four children aged 5 to 12 years were recruited, with 52.4% males. The prevalence of elevated BP and hypertension was 7.5% (108 children) and 16.9% (243 children). The diagnostic test performance, comparing BP equal or greater than 120/80 mmHg screening with BP equal or greater than the 95th percentile diagnostic criteria of AAP 2017 (reference test), showed the probability of a positive BP equal or greater than 120/80 mmHg screening and the probability of a negative BP equal or greater than 120/80 mmHg screening were 57.6% and 99.6%, respectively. The likelihood that children with a positive screening test truly had hypertension and that children with a negative screening test truly did not have hypertension were 96.6% and 92.1%, respectively. The accuracy of the screening test was 92.5%. To increase the sensitivity of 81.1% of the hypertension screening test, further analysis identified the optimal cut-off values of systolic BP of equal or greater than 114 mmHg and diastolic BP of equal or greater than 63 mmHg (area under the curve 0.94, 95% CI 0.92 to 0.96 and 0.86, 95% CI 0.83 to 0.89, respectively). BMI was a significant risk factor for hypertension with an odds ratio of 1.19 (95% CI 1.16 to 1.23). Conclusion: The prevalence of hypertension in children aged 5 to 12 years in lower northern Thailand was high. Utilizing the simplified BP of equal or greater than 120/80 mmHg cut-off could be a valuable screening tool for primary healthcare providers in early detecting pediatric hypertension.