Beware of Striking Medical Studies

A large-scale statistical analysis shows that medical studies revealing “very large effects” seldom stand up when other researchers try to replicate them.

By | October 25, 2012

Wikimedia, BmramonClinical trials that find very large effects for medical treatments tend not to hold up under further scrutiny, according a study published this week (October 24) in the Journal of the American Medical Association. The authors say the findings should be a reminder to be cautious about exciting early studies.

Analyzing data from 230,000 clinical trials across various disciplines, a team led by Stanford University epidemiologist John Ioannadis found that researchers rarely succeed in replicating study results that claimed a “very large effect.” “The effects largely go away; they become much smaller,” Ioannidis told the Los Angeles Times. “It's likely that most interventions that are effective have modest effects.”

The analysis also revealed that studies reporting outstanding results tended to have used fewer than 100 subjects, so the effects are more likely to be influenced by chance. Moreover, “very large effect” studies usually measure intermediate effects, such as whether statins reduce LDL cholesterol in the blood, rather than more meaningful outcomes like the incidence of disease or death.

The authors suggest that the results should reiterate to patients, physicians, and policymakers that drugs or devices that get glowing reports in small, early-stage trials should be treated with caution—rather than rushed through for approval.

Gordon Guyatt, a clinical epidemiologist at McMaster University in Hamilton, Canada, who was not involved in the study, agreed. People tend to “get excited, and misguidedly so” by these “very large effect” results, he told the LA Times.

(Hat tip to GenomeWeb)

Add a Comment

Avatar of: You

You

Processing...
Processing...

Sign In with your LabX Media Group Passport to leave a comment

Not a member? Register Now!

LabX Media Group Passport Logo

Popular Now

  1. Monsanto Buys Rights to CRISPR
    The Nutshell Monsanto Buys Rights to CRISPR

    The US agribusiness secures a global, nonexclusive licensing agreement from the Broad Institute to use the gene-editing technology for agricultural applications.

  2. How Plants Evolved Different Ways to Make Caffeine
  3. ESP on Trial
    Foundations ESP on Trial

    In the 1930s, parapsychologist Joseph Banks Rhine aimed to use scientific methods to confirm the existence of extrasensory perception, but faced criticisms of dubious analyses and irreproducible results.

  4. Another DNA Vaccine for Zika Shows Promise
RayBiotech