Pediatric hypertension prevalence with 1 vs. 2 vs. 3 within-visit blood pressure readings (NHANES 2013-2020)

To compare hypertension prevalence using 'initial' blood pressure (BP), 'subsequent' BP (averaged second and third readings) and 'total' BP (averaged three readings), we included 8-17-year-old youth with three BP readings from NHANES 2013-2020. From 2013-2016, BP was obtained using auscultation (manual protocol, MP) and subsequently, using oscillometry (automated protocol, AP). We excluded subjects with 'zero' diastolic blood pressure (DBP). In 5656 subjects, clinical hypertension (high systolic blood pressure [SBP] and/or DBP) prevalence was highest with 'initial' BP (350/5 642, 6.2% [95% CI 5.6-6.9%]), lower with 'subsequent' BP (289/5 642, 5.1% [4.6-5.7%], p < 0.001), and lowest with 'total' BP (251/5 642, 4.4% [3.9-5.0%], p < 0.001). Both MP and AP groups maintained this trend with a significantly lower hypertension prevalence with 'total' vs. 'subsequent' BP. An exception to the trend occurred in the AP group for three conditions: diastolic hypertension, hypertension in high BMI and Hispanic subjects. Diastolic hypertension prevalence with 'subsequent' DBP (86/2 285, 3.8% [3.1-4.6%]) exceeded that with 'initial' DBP (83/2 285, 3.6% [2.9-4.5%]) and was lowest with 'total' DBP (59/2 285, 2.6% [2.0-3.3%]). Diastolic hypertension prevalence was higher (126/5 642, 2.2% [1.9 - 2.7%]) with the 2016 European guidelines (same as 'subsequent' DBP) than with 'total' DBP (94/5 642, 1.7% [1.4 - 2.0%]). Our findings support the inclusion of the first BP reading in BP categorization, as 'total BP' leads to lower hypertension classification than 'subsequent' BP.