–Cardiologists discuss the screening controversy in 140 characters or less.
My recent post on the debate over cholesterol screening in children provoked a fascinating discussion on Twitter, including comments from several highly knowledgeable experts and clinicians.
The discussion started when James Stein, a preventive cardiologist at the University of Wisconsin), tweeted: Lipid screening in kids. Perfect example of need for shared decision making, not doctor paternalism.
Population Strategy
Elizabeth Matsui, a pediatrician at Johns Hopkins, added: seems like pop-level strategies focusing on physical activity & healthy diet make most sense
The debate began in earnest when Sek Kathiresan, a cardiologist and genetics researcher at the Broad Institute, at first agreed with Matsui, but then appeared to defend screening: absolutely re diet and exercise counseling for all. shouldn’t preclude finding outliers highest risk for premature death.
Matsui defended a population strategy over screening and treatment of individuals: until we can predict 4 indiv, seems targeting risk factors 4 unhealthy pop’n makes sense. Wld b interesting study
How big would a trial need to be?
Ethan Weiss, a UCSF cardiologist and researcher, said he was trying to wrap my head around the feasibility of such a study …can you guys estimate the number of pts and years f/u needed to do an outcomes based trial of +/- screening? (Kathiresan’s answer: gazillion)
Stein defended the idea of a trial: Not that difficult. Large simple trial w/extended f/up. Air pollution, poverty, gun violence more important. Not too hard if impt. Lg simple trial, big data, natural experiments. $ + time better spent on poverty, air, guns. Responding to the point that the trial would be too expensive he added: I can’t estimate it, but if too massive & expensive it can’t be that impt. If impt, then we do it simply & wait. (Editor’s note: I think this would be a good subject for a very large randomized registry study using EHR records.)
Kathiresan mocked the absurdity of the USPSTF papers, which reported the results of the systematic review of the evidence about screening: Let’s do systematic review on clinical ?; find no studies on ?; Let’s write paper. Bizarre! …Have never before seen a peer-reviewed paper where the results section is blank.
Stein disagreed: NOT bizarre. Important to be humble about what we do and don’t know, what we think we know, potential to be wrong. …Not a parody – it’s impt. All this chol screening talk distracts + wastes money.
The LDL Hypothesis
Pablo Corral, an internist and lipidologist, defended screening based on the prevalence of familial hypercholesterolemia (FH): FH prevalence 1/200-250. Most common inherited disease …congenital hypothyroidism 1/3000-5000, routine screening. FH 1/200-300. Stein responded: Its a matter of risks, not prevalence. You are missing the point.
Weiss defended screening with a restatement of the LDL hypothesis: I think it’s important! There is good evidence that CV risk increases linearly w/lifetime exposure to LDL
Stein: This is too important to just assume risk of screening outweighs potential benefit… No doubt childhood LDL-C important. Screening and treatment are harder issues.
Weiss made the point that the absence of evidence in favor of screening does not mean that screening is harmful: I want answers too, but we should not assume screening harms just because robust evidence does not show it helps
Kathiresan pointed out the overwhelming evidence in support of statins in older populations: In light of all of this, should we perform a CVOT in every remaining age stratum? Stein responded: You know better. It’s an issue of the magnitude of benefits, harms, duration of exposure, and competing risks. Kathiresan: much of this is already known for statins. Stein: Not in kids & young adults + much of the data based on RRRs, not ARRs. Why the aversion to shared-decision making?
Common Sense Medicine or Opinion-Based Medicine?
Kathiresan said the decision to screen is common sense: In absence of CVOT and screen/no-screen RCT evidence in every age strata, we will need to use common sense. Stein: Common sense = opinion; honest to share w/patients & get their input. What seems obvious often turns out incorrect.
Kathiresan: not just opinion. It’s a recommendation based on synthesis of available evidence.
Stein: AKA, your opinion.
Kathiresan: well then, all of medicine is just opinion.
Weiss: and hence the gravitational pull toward absolute nihilism
Stein: Not true. I just am making a case for humility & respecting competing interests beyond lowering LDL-C.
Finally, the first author of the USPSTF report, Kirsten Bibbins-Domingo said this discussion was exactly what the authors hoped to provoke: gr8 discussion- this + research is what we hope to prompt with “I” statement.
Related Reading:
- Controversy Over Cholesterol Testing for Children
- WSJ Article Fails To Raise Key Questions About Cardiovascular Risk In Children
- Guest Post: Children Should Have Their Cholesterol Checked
- Guest Post– Universal Screening for Dyslipidemia In Children: A Debate With Equipoise, But Tarnished By Industry Influence
- Part 1: The National Lipid Association and the FH Guidelines
- Industry PR Efforts Influence Debate On Cholesterol Screening Guidelines For Children
- Experts Disagree About Cholesterol Screening In Kids
I’d love to know whether Gerd Gigerenzer has an opinion on this. His book on risk is one of the best things I’ve read in a couple of decades.
https://www.amazon.co.uk/Reckoning-Risk-Learning-Live-Uncertainty/dp/0140297863