The Preventive Services Task Force effect
One notable recent development in the field of pediatric hypertension was the 2013 statement by the U.S. Preventive Services Task Force that reinforced a similar conclusion the group had reached a decade before, in 2003. In 2013, the USPSTF said that following a review of the evidence “the USPSTF concludes that the current evidence is insufficient to assess the balance of benefits and harms of screening for primary hypertension in asymptomatic children and adolescents to prevent subsequent cardiovascular disease in childhood or adulthood. (I statement)” (Pediatrics. 2013 Nov;132[5]:907-14).
The USPSTF’s 2013 reassertion of this position triggered several strong reactions from pediatric hypertension specialists, who critiqued the Task Force’s analysis as being overly restrictive. Among those weighing with comments that highlighted the flaws in the Task Force’s reasoning were Dr. Falkner, Dr. Brady, and Dr. Steinberger. Earlier in 2013, before the Task Force statement, Dr. Daniels wrote a commentary with similar arguments in favor of routine blood pressure measurements in response to a published assessment of pediatric blood pressure screening that largely presaged what the USPSTF said.
In brief, the USPSTF analysis “was flawed by an overly-narrow selection of evidence,” Dr. Steinberger said recently. “Short-term and observational studies were not considered. We think that in the absence of perfect data the practitioner must use common sense when superior evidence does not exist. The question of whether hypertension in adults can be prevented or modified by early intervention will never be answered unless we continue to measure blood pressure in children.”
“One of the problems with the USPSTF statement was the questions they addressed: Is blood pressure in children and adolescents clearly associated with hard cardiovascular disease outcomes in adults? That is a very tough question to answer. It would need studies that are 30, 40 years in duration, and is almost unanswerable,” said Dr. Daniels in an interview. “I think the USPSTF paid less attention to the fact that clearly a certain percentage of children and adolescents with hypertension already have developed left ventricular hypertrophy, increased carotid intimal-medial thickness and vascular stiffness. This shows that higher blood pressure in the short term is having several adverse effects on the cardiovascular system. If you insist on seeing a connection between pediatric blood pressure and adult outcomes there will always be insufficient evidence.”
Although, as Dr. Steinberger pointed out, the International Childhood Cardiovascular Cohort Consortium has been putting together long-term follow-up data from seven observational cohorts established in several different world regions. Collectively these seven cohorts include more than 340,000 people who have now been followed for about 40 years. This analysis may soon yield more definitive insight into the long-term consequences of childhood hypertension, Dr. Steinberger said.
Another relevant issue is that prevention of adult cardiovascular disease “is not why children are screened for hypertension, or at least not the primary reason,” Dr. Falkner said. “They are screened to find high blood pressure with an underlying cause, like coarctation of the aorta, which is only picked up by first noting a high blood pressure. Several other cardiovascular and renal disorders that can exist in childhood can also cause high blood pressure and measuring blood pressure is the only way to find them. It would be a tragedy to miss coarctation of the aorta by not measuring blood pressure.”
The family practice position
Despite rejection of the USPSTF analysis by many pediatric hypertension specialists, the USPSTF position has been officially embraced by the family practice community. The American Academy of Family Practice has adopted the USPSTF position as its own, although family practice physicians are also quick to point out that the USPSTF conclusion does not say that pediatric blood pressures should not be measured.
“An I level from the USPSTF doesn’t mean that screening is harmful or shouldn’t be done, just that more research is needed to fully evaluate if blood pressure screening in childhood has long-term health impacts,” said Margaret A. Riley, MD, a family practice physician at the University of Michigan in Ann Arbor with an interest in pediatric hypertension.
“I think the I rating has had little impact on practice. Measuring blood pressure is a routine and standard part of office practice. If the USPSTF had given blood pressure screening a D rating, causing more harm than good, that would be different. In my practice I screen blood pressure at every visit or at least once a year,” Dr. Riley said in an interview.
That’s the same approach taken by Wanda D. Filer, MD, a family practice physician in York, Pa. and president of the American Academy of Family Physicians. “This does not mean you don’t screen blood pressure, and it doesn’t mean you should screen. It says that data are not there either way. In my office we check everyone age 3 and up, and I think a lot of family practice physicians do that routinely.