Accuracy and Performance of Triage Blood Pressure Measurements in A Real-World Clinic Setting

Objectives: To investigate the agreement and accuracy of triage blood pressure (BP) in a real-world clinic setting, compared with the reference standard. Study design: Paired triage and standardized BP measurements from patients 4 through 21 years old evaluated in an obesity-related hypertension clinic were obtained via chart-review. Triage BPs were measured by a medical assistant or nurse, often by automated device. Triplicate manual BPs were 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 ≥ 5 mmHg. Overall agreement, sensitivity, specificity, positive predictive value, and negative predictive value of triage BP measurements identifying hypertensive BP were determined. Results: One hundred thirty participants with 347 clinic encounters were included. Mean age was 13.3 years (SD 3.94), 76% were Black, and 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 ≥ 5 mmHg when a large adult (RR = 1.49; 95% CI: 1.00, 2.21) or thigh cuff (RR = 1.94; 95% CI: 1.08, 3.51) was required compared with 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 cuffs. Conclusions: There was poor agreement between usual triage and standardized BP measurements, with potential for significant clinical implications. Clinical Trial Registration: ReNEW Clinic Cohort Study (ReNEW), NCT03816462, https://clinicaltrials.gov/ct2/show/NCT03816462.