Thursday, August 25, 2016

A family medicine perspective on cholesterol screening in children

The publication of the U.S. Preventive Services Task Force's updated guidance on screening for lipid disorders in children and adolescents has re-ignited an ongoing debate about the effectiveness (or lack thereof) of pediatric guidelines recommending universal screening for high cholesterol. As it did when it last reviewed this topic in 2007, the USPSTF concluded that there remains insufficient evidence to assess the balance of benefits and harms of this preventive service. Published reactions to this statement were mixed. Labeling lipid screening in children "low-value care," Dr. Thomas Newman and colleagues argued that any potential benefits of screening would likely be outweighed by harms and costs:

Recent analyses suggest possible benefit of statin treatment among selected adults whose 10-year risk of cardiovascular disease (CVD) events is less than the 7.5% value recommended by the American College of Cardiology and American Heart Association, ... although this remains controversial. No models suggest treatment at CVD risk levels anywhere near those seen in children. Because the absolute risk of CVD events in childhood is close to zero, screening and treatment in childhood will likely to lead to costs and harms without quantifiable benefit.

On the other hand, Dr. Stephen Daniels countered that requiring improvements in clinical outcomes such as cardiovascular events to recommend cholesterol screening was inconsistent with the USPSTF's previous recommendation to screen for obesity in children, which focused primarily on evidence for weight reduction:

In its analysis, the USPSTF noted that obesity is a common and serious health problem with long-term adverse consequences for which behavioral change therapy is available and successful. Why should we screen for obesity but have insufficient information to reach a conclusion for screening for heterozygous FH [familial hypercholesterolemia] when there seem to be important parallels in these clinical entities?

Both Dr. Newman and Dr. Daniels raise good points, and although Dr. Newman is himself a pediatrician, their opposing views represent the different perspectives of internists (adult physicians) and pediatricians. Much preventive decision-making in adults, from breast cancer to cardiovascular risk reduction, is driven by 5 to 10-year time frames. To the internist, if a child with high cholesterol at age 13 has a virtually zero risk of having a heart attack by age 23, why bother to screen? To the pediatrician, screening is justified because many childhood conditions have lifelong consequences, and it doesn't make sense to turn a blind eye when an intervention is available. Not every overweight child is destined to become an obese adult, but many will. Kids who don't know they have high cholesterol levels are probably less likely to behave in ways that lower those levels (even though good nutrition and physical activity should be emphasized at all well-child visits), and may end up with two-plus additional decades of atherosclerotic damage by the time they are diagnosed as thirty-something adults.

As a family physician who cares for patients across the entire lifespan, from newborns to nonagenarians (and centenarians, when I eventually see one in the office or hospital), I am sympathetic to both perspectives. I don't screen the vast majority of my child and adolescent patients for high cholesterol, and I do not prescribe cholesterol-lowering medications to children. My threshold for testing a child's cholesterol levels is based on my assessment that an abnormal result would alter my approach or the behavior of my patient and/or his or her parents. For example: the overweight child whose parents aren't particularly motivated by body mass index but who might be moved by a blood test. Or the normal-weight adolescent whose diet consists mostly of fast food and doesn't do any physical activity more vigorous than texting. I am all for debating the evidence, while recognizing that medicine remains an art.