Persistent Hypertension in Children and Adolescents: A 6-Year Cohort Study.

OBJECTIVES: To determine the natural history of pediatric hypertension. METHODS: We conducted a 72-month retrospective cohort study among 165 primary care sites. Blood pressure measurements from two consecutive 36 month periods were compared. RESULTS: Among 398 079 primary care pediatric patients ages 3 to 18, 89 347 had >= 3 blood pressure levels recorded during a 36-month period, and 43 825 children had >= 3 blood pressure levels for 2 consecutive 36-month periods. Among these 43 825 children, 4.3% (1881) met criteria for hypertension (3.5% [1515] stage 1, 0.8% [366] stage 2) and 4.9% (2144) met criteria for elevated blood pressure in the first 36 months. During the second 36 months, 50% (933) of hypertensive patients had no abnormal blood pressure levels, 22% (406) had elevated blood pressure levels or <3 hypertensive blood pressure levels, and 29% (542) had >= 3 hypertensive blood pressure levels. Of 2144 patients with elevated blood pressure in the first 36 months, 70% (1492) had no abnormal blood pressure levels, 18% (378) had persistent elevated blood pressure levels, and 13% (274) developed hypertension in the second 36-months. Among the 7775 patients with abnormal blood pressure levels in the first 36-months, only 52% (4025) had >= 3 blood pressure levels recorded during the second 36-months. CONCLUSIONS: In a primary care cohort, most children initially meeting criteria for hypertension or elevated blood pressure had subsequent normal blood pressure levels or did not receive recommended follow-up measurements. These results highlight the need for more nuanced initial blood pressure assessment and systems to promote follow-up of abnormal results.