Update on Blood Pressure Screening for Children

There is not enough evidence to assess the benefit or harm of routine blood pressure screening in children who do not have symptoms of high blood pressure or an underlying health problem that could cause hypertension, according to an update from the U S Preventive Services Task Force (USPSTF).

The recommendation, “Screening for Primary Hypertension in Children and Adolescents: U.S. Preventive Services Task Force Recommendation Statement,” updates a previous statement from the USPSTF from 2003, which reached a similar conclusion.

The USPSTF reviewed the evidence on screening and diagnostic accuracy of screening tests for blood pressure in children and adolescents, the effectiveness and harms of treatment of screen-detected primary childhood hypertension, and the association of hypertension with markers of cardiovascular disease (CVD) in childhood and adulthood.

The prevalence of hypertension in children and adolescents in the United States has been reported at 1% to 5%, the USPSTF noted. Primary hypertension in children and adolescents is associated with elevated body mass index (BMI) and other risk factors (low birthweight, male sex, ethnicity, and family history of hypertension). The prevalence has increased over the past several decades, probably because of the increase in childhood overweight and obesity. The prevalence of hypertension among obese children in the United States is estimated at 11%.

The USPSTF review found inadequate or no direct evidence about the following:

• The diagnostic accuracy of screening for elevated blood pressure with sphygmomanometry in the clinical setting. Such screening may be reasonably sensitive for identifying children and adolescents with hypertension, but false-positive results may occur with normalization of subsequent blood pressure measurements.

• Whether routine blood pressure measurement accurately identifies children and adolescents who are at increased risk for CVD in adulthood and whether routine blood pressure measurement accurately identifies children and adolescents who are at increased risk for adult hypertension or other intermediate measures of adult CVD.

• Whether treatment of elevated blood pressure in children or adolescents results in sustained decreases in blood pressure in childhood.

• What health outcomes are associated with interventions to treat primary hypertension in childhood or adolescence.

• The potential harms of screening for primary hypertension in children and adolescents and of pharmacological or nonpharmacological treatment of elevated blood pressure in childhood or adolescence.

The USPSTF review advised that when deciding whether to screen children and adolescents for hypertension, clinicians consider the following factors:

• Potential preventable burden. The increasing prevalence of hypertension in children and adolescents, possibly driven by childhood obesity, suggests that identification and treatment of hypertension is likely to become a significant health care issue. The goal may be viewed within a larger framework of adult CV risk reduction.

• Potential harms. With evidence suggesting that false-positive results may occur with clinic-based screening for hypertension, unnecessary secondary evaluations or treatments may be common. Pharmacological interventions have been shown to be well-tolerated over relatively short periods. Treatment of hypertension in childhood and adolescence with pharmacological agents is done for a much longer period, and adverse effects of such pharmacotherapy may occur.

• Current practice. Current screening practice for elevated blood pressure typically involves measurement of blood pressure in office-based health care settings as part of well-child or sports preparticipation examinations. National High Blood Pressure Education Program (NHBPEP) percentile charts help interpret systolic blood pressure and diastolic blood pressure measurements and categorize them as "normal," "prehypertension," or "hypertension" on the basis of the child’s age, height, and sex for each year of the child's life from age 3 to 18 years.

• Screening tests. The consensus-based guidelines of the NHBPEP and National Heart, Lung, and Blood Institute define hypertension in children on the basis of percentiles according to age, height, and sex. The NHBPEP provides guidance on optimal blood pressure measurement techniques, such as appropriate cuff size and type of sphygmomanometer. Blood pressure should be measured in a controlled environment after 5 minutes of rest, with the patient seated and the right arm supported at heart level.

• Treatment. Stage 1 hypertension in children is treated with lifestyle and pharmacological interventions. Medications are not recommended as first-line therapy. Lifestyle interventions include weight reduction in children who are overweight or obese, increased physical activity, and restricted sodium intake, as well as education and counseling. The NHBPEP recommends medication for children with stage 2 hypertension and those with hypertension that is unresponsive to lifestyle modification.

• Screening intervals. Several organizations recommend routine screening of blood pressure at well-child visits starting at age 3 years, based on consensus.

The USPSTF noted that evidence is needed to ascertain the effectiveness and comparative effectiveness of pharmacological and lifestyle interventions to achieve sustained reductions in blood pressure and longer-term modification of adult hypertension and CV risk in children with primary hypertension.

The review also noted that clinical decisions involve more considerations than evidence alone and suggested that clinicians should understand the evidence but individualize decision making to specific patients and situations.

The USPSTF recommendation will appear in the November 2013 issue of Pediatrics and is published online in Pediatrics October 7, as well as in the Annals of Internal Medicine.