Toddler Obesity Plummeting? Headlines 5, Science 0

A toddler obesity statistic from last week’s CDC report in the Journal of the American Medical Association was fished out of the depths of the report and elevated to headline status, generating many millions of media impressions. Here’s a sampling:

  • NY Times: Obesity Rate for Young Children Plummets 43%
  • Wall Street Journal: US Childhood Obesity Rates Fall 40% in Decade
  • Daily Mail: Childhood Obesity Rate Cut Nearly in Half Over Past Decade
  • USA Today: Child Obesity Rates Drop 43% in Past Decade
  • Washington Post: These 6 Reasons Explain Why Childhood Obesity Has Fallen So Much

All these celebratory headlines provided a great setup for the fourth birthday party of the First Lady’s Let’s Move campaign the very next day. The only casualty was the science.

The real conclusion of the paper that spawned all these headlines was that “there have been no significant changes in obesity prevalence in youth or adults between 2003-2004 and 2011-2012. Obesity prevalence remains high.”

The authors went to some length to put the subgroup analyses into perspective, saying:

Because these age subgroup analyses and tests for significance did not adjust for multiple comparisons, these results should be interpreted with caution…When multiple statistical tests are undertaken, by chance some tests will be statistically significant (eg, 5%of the time using α of .05).

In other words, the authors knew and cautioned readers that they did enough subgroup analyses so that those findings were wobbly at best and perhaps just a fluke. The headlines and the celebrations reflected none of the “caution” advised by the scientists. But they did fit the health policy agenda for the week.

“Get your facts first, then you can distort them as you please.” — Mark Twain

Click here to read more in Slate and here for a concise analysis by Asheley Cockrell Skinner at UNC Chapel Hill.

Toddler Toes, photograph © Paul Hocksenar / flickr

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