Screening for hypercholesterolemia - new guideline recommends screening of all children and drug therapy for those older than seven. Wise?

Pediatricians and family physicians alarmed by the growing prevalence of obesity in children in their waiting rooms and increasingly frustrated by their lack of success in encouraging parents to try to get their child(ren) to lose weight and exercise more may welcome the recommendations of the Committee on Nutrition of the American Academy of Pediatrics.<1> The recommendations reverse previous guideline recommendation for obese children and now recommend cholesterol screening and treatment. Now they can do something. But should they follow the guidelines?

The new guidelines recommend screening for hypercholesterolemia in all children beginning at 2 years of age and (presumably)repeated annually. The screening is two-pronged beginning with an individual assessment of risk based on family history and the child’s current obesity and presence of other risk factors for cardiovascular disease (CVD). Then, those 8 years of age or over are treated with diet plus pharmacotherapy depending on the levels of hyperlipidemia.

Alas there are no clinical trials of drugs for hyperlipidemia in children and hence no evidence that drug therapy will reduce the child’s risk of cardiovascular disease later in life. Nor are there even medium term studies of risk of taking these drugs in children. There is some evidence that children with a homozygous defect in their metabolism of cholesterol (familial hypercholesterolemia) do respond to drugs commonly used to treat hypercholesterolemia in adults and that this may result in some improvement in the health of their arteries by slowing the normal growth of lipid and plaque changes that occur in these high risk children. Although in the short course of these studies the usual side-effects seen with these drugs in adults were also seen in children it will take much longer term studies to assess risk in growing children.

What’s wrong with the recommendation that children be screened for hyperlipidemia?

Screening is the deliberate selection of “healthy individuals for the purpose of separating them into groups with high and low probabilities of a given disorder”<2>, in this case all children over the age of two. The purpose is to identify those at risk and to treat them at an earlier point in time to prevent later disease. In screening there is “the implicit promise that those who volunteer to be screened will benefit.” <2>

This is a bold promise in any screening question but it is an audacious promise to children with hypercholesterolemia. There is but fragmentary and tangential evidence of benefit. Granted the evidence needed to make the promise will be difficult to attain, requiring large clinical trials lasting for decades and demanding that children and their parents administer daily doses of cholesterol lowering drugs (or placebos).

There is even no evidence (and probably no expectation) that even a fraction of children and their parents will take cholesterol lowering drugs for even a few months for a few years. We can expect considerable non-compliance, especially as children leave the parental grasp.

The Academy guidelines do not consider the costs of their recommendations - costs to individuals and to society. There are approximately 72 million children (under the age of 18) in the U.S of whom 10.6 million have no health insurance and would likely have no way to pay for screening and the decades of cholesterol lowering drugs. Health insurance companies in the US and technology assessment agencies in Canada and other countries should proceed cautiously when assessing this new offering by the American Academy of Pediatrics. Money might be more wisely spent elsewhere.

The screening for hypercholesterolemia recommendations of American Academy of Pediatrics meet few of the criteria for an acceptable screening intervention. <2,4> . Failure to meet the promise of an efficacious treatment, failure to assess harm, failure to assess and evaluate cost and opportunity cost ought to render this set of recommendations inoperable.

The algorithm, however, might be useful to pediatricians and family physicians faced with individual obese children with multiple risk factors for cardiovascular disease. They may opt to evaluate the lipid status of these patients and to consider lipid lowering agents after assessing the receptivity of parents and children to life-long therapy and the probabilities of reasonable compliance. But this is not screening, it is clinical practice, or as Sackett and Holland have it, “case finding”.

References:
1. Daniels SR, Greer FR, and the Committee on Nutrition. Lipid screening and cardiovascular health in childhood. Pediatrics 2008;122:198-208
2. Sackett DL, Holland WW. Controversy in the detection of disease. Lancet 1975
3. Census Brief. Children without health insurance. CENBR/98-1 March 1998
4. UK National Screening Committee. Criteria for appraising the viability, effectiveness and appropriateness of a screening program.