Poor Accuracy of Triage Blood Pressure Measurements in a Pediatric Obesity Hypertension Clinic

Accurate triage blood pressure (BP) measurements are essential for clinical decision making. We investigated the agreement and diagnostic accuracy of usual triage vs. standardized BP measurements in an obesity-related hypertension clinic. This was a retrospective study of paired triage and standardized BP measurements from patients 4-21 years old. Triage BPs are measured by a medical assistant or nurse, often by automated device. Triplicate manual BP measurements are obtained by the clinic physician. Bland-Altman analyses determined mean differences between paired triage and mean standardized BPs. GEE- based multivariable relative risk (RR) regression determined the RR of triage BP overestimation by [≥]5mmHg. Overall agreement, sensitivity, specificity, positive predictive value, and negative predictive value of usual triage BP measurements identifying hypertensive BP were determined. 130 participants with 347 clinic encounters were included. Mean age was 13.3 years (standard deviation 3.94), 76% were Black race, 58% were male. Overall mean systolic and diastolic BP difference was 8.7 mmHg (95% limits on agreement: -16.66, 34.07) and 4.1 mmHg (95% limits on agreement: -18.56, 26.68), respectively. Triage systolic BP was more likely overestimated by [≥]5mmHg when a large adult (RR=1.49; 95% confidence interval: 1.00, 2.21) or thigh cuff (RR=1.94; 95% confidence interval: 1.08, 3.51) was required vs. when a child/adult cuff was required. Overall agreement in identifying hypertensive BP was 57.6%. Sensitivity (52.6%), specificity (63.4%), positive predictive value (60.8%), and negative predictive value (55.3%) were low across all cuff sizes. There was poor agreement between usual triage and standardized BP measurements, with potential for significant clinical implications. Clinical Trial RegistrationReNEW Clinic Cohort Study (ReNEW), NCT03816462, https://clinicaltrials.gov/ct2/show/NCT03816462