<p><strong>OBJECTIVES: </strong>To determine the natural history of pediatric hypertension.</p>

<p><strong>METHODS: </strong>We conducted a 72-month retrospective cohort study among 165 primary care sites. Blood pressure measurements from two consecutive 36 month periods were compared.</p>

<p><strong>RESULTS: </strong>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 &lt;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.</p>

<p><strong>CONCLUSIONS: </strong>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.</p>

<p><strong>BACKGROUND AND OBJECTIVES: </strong>Pediatric hypertension predisposes children to adult hypertension and early markers of cardiovascular disease. No large-scale studies have examined diagnosis and initial medication management of pediatric hypertension and prehypertension. The objective of this study was to evaluate diagnosis and initial medication management of pediatric hypertension and prehypertension in primary care.</p>

<p><strong>METHODS: </strong>Retrospective cohort study aggregating electronic health record data on &gt;1.2 million pediatric patients from 196 ambulatory clinics across 27 states. Demographic, diagnosis, blood pressure (BP), height, weight, and medication prescription data extracted. Main outcome measures include proportion of pediatric patients with ≥3 visits with abnormal BPs, documented hypertension and prehypertension diagnoses, and prescribed antihypertensive medications. Marginal standardization via logistic regression produced adjusted diagnosis rates.</p>

<p><strong>RESULTS: </strong>Three hundred ninety-eight thousand seventy-nine patients, ages 3 to 18, had ≥3 visits with BP measurements (48.9% girls, 58.6% &lt;10 years old). Of these, 3.3% met criteria for hypertension and 10.1% for prehypertension. Among practices with ≥50 eligible patients, 2813 of 12 138 patients with hypertension (23.2%; 95% confidence interval, 18.2%-28.2%) and 3990 of 38 874 prehypertensive patients (10.2%; 95% confidence interval, 8.2%-12.2%) were diagnosed. Age, weight, height, sex, and number and magnitude of abnormal BPs were associated with diagnosis rates. Of 2813 diagnosed, persistently hypertensive patients, 158 (5.6%) were prescribed antihypertensive medication within 12 months of diagnosis (angiotensin-converting enzyme inhibitors/angiotensin receptive blockers [35%], diuretics [22%], calcium channel blockers [17%], and β-blockers [10%]).</p>

<p><strong>CONCLUSIONS: </strong>Hypertension and prehypertension were infrequently diagnosed among pediatric patients. Guidelines for diagnosis and initial medication management of abnormal BP in pediatric patients are not routinely followed.</p>

<p>The United States lacks a system to use routinely collected electronic health record (EHR) clinical data to conduct comparative effectiveness research (CER) on pediatric drug therapeutics and other child health topics. This Special Article describes the creation and details of a network of EHR networks devised to use clinical data in EHRs for conducting CER, led by the American Academy of Pediatrics Pediatric Research in Office Settings (PROS). To achieve this goal, PROS has linked data from its own EHR-based "ePROS" network with data from independent practices and health systems across the United States. Beginning with 4 of proof-of-concept retrospective CER studies on psychotropic and asthma medication use and side effects with a planned full-scale prospective CER study on treatment of pediatric hypertension, the Comparative Effectiveness Research Through Collaborative Electronic Reporting (CER(2)) collaborators are developing a platform to advance the methodology of pediatric pharmacoepidemiology. CER(2) will provide a resource for future CER studies in pediatric drug therapeutics and other child health topics. This article outlines the vision for and present composition of this network, governance, and challenges and opportunities for using the network to advance child health and health care. The goal of this network is to engage child health researchers from around the United States in participating in collaborative research using the CER(2) database.</p>