Two commentaries published in JAMA offer skeptical perspectives on the roles of direct-to-consumer (DTC) cardiac tests and vitamin D in cardiovascular health.
In the first commentary, Kimberly Lovett and Bryan Liang write that DTC screening tests “likely pose more risk than benefit to patients,” and point out that for companies selling these tests there is no requirement “for full disclosure in advertising, informed consent, pretest evaluation, or posttest counseling.” Some screening tests, including tests for carotid artery stenosis, PAD, AF, and AAA, are not recommended for most people by organizations like the USPSTF and the ACC/AHA. Other tests, like CRP, lipid tests, and coronary calcium, have received limited endorsements, but only in carefully selected patients, the authors write.
They recommend that FDA should regulate consumer screening tests, that the companies provide pretest consultation with a qualified professional, and that DTC tests should be included in the FDA Medwatch database.
In the second commentary, Sue Shapses and JoAnn Manson, who served on the Institute of Medicine committee on vitamin D, explain why the role of vitamin D in heart disease, stroke, hypertension, and diabetes played only “an inconsequential role in determining the population needs for vitamin D” in the recent IOM report.
Shapses and Manson acknowledge the “biological plausibility for a role of vitamin D in the prevention of cardiovascular disease and diabetes” but, citing deficiencies in both observational and randomized evidence, they conclude that “the evidence from available research is inconsistent, inconclusive as to causality, and not sufficient to inform nutritional requirements.” Several ongoing randomized trials may provide better evidence within 5 to 6 years, they write.
Comment: I particularly enjoyed the following paragraph in the commentary by Lovett and Liang. It perfectly captures the insidious and devious nature of disease-mongering:
These DTC companies market primarily by targeting consumer fear about undetected disease and acquiring symptomatic, sometimes fatal, disease. One company, for example, offers an online 8-question carotid artery stenosis (CAS) risk assessment; if any question is answered as yes, the next Web page informs consumers that they are at risk and should consider screening. If all questions are answered no, the next page states, “Good news—your responses indicate that you are currently not at high risk for carotid artery disease. But remember that many people with this condition do not experience symptoms, so you may want to consider being screened anyway.”
Are there actually DTC’s for Vitamin D? I suppose there are for calcium plus D supplements, but I can’t recall one for D alone.
Neither are exactly pricely and thus require magic potion branding and the alluring lady in white.