Hypertension underdiagnosed in children and adolescents

22 August 2007

MedWire News: Hypertension and prehypertension are frequently undiagnosed in children and adolescents, US researchers highlight.

“If abnormal blood pressure (BP) is not identified by a patient’s pediatric clinician, it may be years before the abnormal blood pressure is detected, leading to end-organ damage,” say David Kaelber (Harvard Medical School, Boston, Massachusetts) and colleagues.

“Because effective treatments for abnormal blood pressure exist, these long-term sequelae can be avoided with early diagnosis.”

Pediatric hypertension is increasing in prevalence due to the pediatric obesity epidemic, but the diagnosis is complicated because BP values vary with age, gender, and height, Kaelber and team explain in the Journal of the American Medical Association.

They examined the frequency of undiagnosed hypertension and prehypertension in a cohort of 14,187 children and adolescents, aged 3 to 18 years, who attended outpatient clinics from 1999 to 2006.

The team identified 507 (3.6%) children with hypertension, of whom 131 (26%) had a diagnosis of hypertension or elevated BP documented in their electronic medical records.

Factors increasing the chances of a patient being correctly diagnosed with hypertension included a 1-year increase in age over age 3 years (odds ratio [OR]=1.09), more than three elevated BP readings (OR=1.77), increase of 1% in height-for-age percentile (OR=1.02), having an obesity-related diagnosis (OR=2.61), and number of BP readings in the stage 2 hypertension range (OR=1.68).

Of the 485 (3.4%) children and adolescents with prehypertension, 55 (11%) had an appropriate diagnosis documented in their electronic medical records.

Patients with more than three elevated BP readings, at an OR of 3.07, and older children, at an OR of 1.21 for each 1-year increase in age over age 3 years, were more likely to be diagnosed with prehypertension than other children.

Kaelber et al conclude: “Our study documents the underdiagnosis of pediatric hypertension and prehypertension in a large pediatric population during an extended period of time.” ‘

They suggest that “the relatively poor identification of abnormal blood pressure could be remedied by a clinical decision support algorithm built into an electronic medical record that would automatically review current and prior blood pressures, ages, heights, and sex to determine if abnormal blood pressure criteria had been met.”

JAMA 2007; 298: 874-879