Using simplified blood pressure tables to avoid underdiagnosing childhood hypertension

BACKGROUND: Recent studies have revealed that hypertension remains underdiagnosed in a significant number of children despite their recorded office blood pressure (OBP) exceeding the recommended fourth report OBP thresholds. Simplified OBP thresholds have been proposed to reduce this underdiagnosis of hypertension in children. In clinical practice, OBP screened as elevated according to the fourth report OBP thresholds are referred for ambulatory blood pressure (ABP) monitoring to rule out 'white coat' hypertension. OBJECTIVES: The present study tested the usefulness of simplified OBP thresholds to screen abnormal OBP for ABP monitoring referral. METHODS: A total of 155 subjects were retrospectively analyzed with paired OBP and ABP recordings obtained from an outpatient referral clinic. OBP recordings were classified as abnormal according to the simplified and fourth report OBP thresholds. ABP measurements were classified as abnormal according to the ABP reference tables. RESULTS: Simplified blood pressure (BP) tables correctly identified all OBP classified as abnormal according to fourth report BP thresholds (kappa [kappa] 0.72 [95% CI 0.61 to 0.83]) for systolic OBP; kappa 0.92 [95% CI 0.86 to 0.99] for diastolic OBP). OBP classified as abnormal by the simplified BP thresholds and by the fourth report BP thresholds performed similarly for correctly identifying abnormal ABP measurements as per ABP references (overlapping 95% CIs of the sensitivity, specificity and predictive values and likelihood ratios). CONCLUSIONS: Simplified BP tables, proposed to reduce the underdiagnosis of hypertension in children, can serve as a useful screening tool to decide a referral for ABP monitoring. Future prospective studies are needed to establish these findings.