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About That Finding…

Medical studies that show large effects often don't hold up under further scrutiny, a new paper published in the Journal of the American Medical Association says. Stanford University's John Ioannidis and his colleagues analyzed clinical trial data from the Cochrane Database of Systematic Reviews and found that "when additional evidence is obtained, most of the very large treatment effects become much smaller and many lose their nominal significance," the authors write.

Ioannidis and his colleagues add that while there are some truly large, well-established effect sizes seen in medical studies, they are quite rare and don't usually affect mortality.

When a new study shows such a large effect, Ioannidis tells the Los Angeles Times that "one should be cautious and wait for a better trial."

The Scan

Transcriptomic, Epigenetic Study Appears to Explain Anti-Viral Effects of TB Vaccine

Researchers report in Science Advances on an interferon signature and long-term shifts in monocyte cell DNA methylation in Bacille Calmette-Guérin-vaccinated infant samples.

DNA Storage Method Taps Into Gene Editing Technology

With a dual-plasmid system informed by gene editing, researchers re-wrote DNA sequences in E. coli to store Charles Dickens prose over hundreds of generations, as they recount in Science Advances.

Researchers Model Microbiome Dynamics in Effort to Understand Chronic Human Conditions

Investigators demonstrate in PLOS Computational Biology a computational method for following microbiome dynamics in the absence of longitudinally collected samples.

New Study Highlights Role of Genetics in ADHD

Researchers report in Nature Genetics on differences in genetic architecture between ADHD affecting children versus ADHD that persists into adulthood or is diagnosed in adults.