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Overdiagnosed babies, NNTs, and the war on statin science

Welcome to the RightCare Weekly, a newsletter that will help you stay on top of all the important news in the ongoing quest to move the U.S. health care system toward the right care. We’ll bring you the most important stories, news articles, and opinion pieces of the week, along with our interpretation of why they’re important and what they mean for patients, doctors, and communities.

  • Earlier this week, Aaron E. Carroll of The Incidental Economist wrote at The Upshot on how definitions of disease have broadened, leading more and more people to be diagnosed with conditions that don’t necessarily cause real problems. The article is an important example of the broader concept of overdiagnosis: by turning normal variation in physiology into medical conditions, we end up “spending billions of dollars on treatments that might not, or don’t, work. We’re making people worry when they don’t have to. And we may be causing actual health problems in the process.” 

Carroll uses the example of the the huge increase in diagnoses of gastroesophogeal reflux disease (GERD) in babies to illustrate the point. Even though spitting up is normal – 50% of healthy infants  spit up more than twice per day, and 95% stop completely without any medical intervention. Some parents and doctors take extensive efforts to prevent infants from spitting up, including special chairs, changes in diet, and prescription drugs. None of these methods has been successful or necessary. The article also notes research showing that giving the babies’ conditions a specific medical name, GERD, made parents more likely to want treatment – even if they knew it was likely to be ineffective.

  • Last week we wrote about a study published in JAMA  exploring the effects of a moderate-intensity physical activity program on seniors’ mobility and independence. The Incidental Economist points out an important nuance in interpreting the study: while there was a statistically significant effect to the exercise program, the number needed to treat (or NNT, meaning the number of people who would need to receive this treatment for one person to benefit) is twenty. This means that nineteen out of twenty seniors who participate in the program won’t have different mobility outcomes because they participated – they’ll still be disabled if they would have without the program, or wouldn’t have had a mobility disability either way. It’s not a disparagement of  the JAMA study, or of the intervention they studied, but it’s an important reminder that many treatments, even ones that seem logical and non-invasive, have to reach a lot of people to have large beneficial effects.

For more on the NNT, see this excellent post by Austin Frakt, also at The Incidental Economist, and theNNT.com.

That would ordinarily have been the end of the fracas over those particular papers, but despite the correction, proponents of statins are calling for a full retraction of the two critical papers. Dr. Newman argues that in this case, it looks like the debate over a specific factual issue in those two papers has turned into an effort to obscure the debate over whether statins are worth it for low-risk patients: “Bottom line: The headline should be that the bestselling pills of all time don’t save lives or reduce major illness for most who take them. But that has been obscured by a war on science.

While the app and the ability to connect to medical records may be useful, it also has potential to create more worry and unnecessary medical intervention. Depending on what information the app collects and how it presents the data to users, it’s easy to imagine situations where the app’s findings lead to yet more overdiagnosis (for example, of harmless variation in heart rhythms). The issue isn’t that people can’t be trusted with their information, it’s that much of the medical data that can be collected is highly uncertain, and presenting it as important may lead people to worry or seek treatment unnecessarily.

The RightCare Weekly is made possible through the generous support of the Robert Wood Johnson Foundation.