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Likelihood of Null Effects of Large NHLBI Clinical Trials Has Increased over Time, 2015, Kaplan & Irvin

Discussion in 'Research methodology news and research' started by LarsSG, Aug 2, 2022.

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  1. LarsSG

    LarsSG Senior Member (Voting Rights)

    Messages:
    370
    This study has a quite striking chart showing how requiring pre-registration of primary outcomes appears to have significantly reduced the likelihood of positive trial findings in this area:

    upload_2022-8-2_9-17-59.png

    Abstract
    Background
    We explore whether the number of null results in large National Heart Lung, and Blood Institute (NHLBI) funded trials has increased over time.

    Methods
    We identified all large NHLBI supported RCTs between 1970 and 2012 evaluating drugs or dietary supplements for the treatment or prevention of cardiovascular disease. Trials were included if direct costs >$500,000/year, participants were adult humans, and the primary outcome was cardiovascular risk, disease or death. The 55 trials meeting these criteria were coded for whether they were published prior to or after the year 2000, whether they registered in clinicaltrials.gov prior to publication, used active or placebo comparator, and whether or not the trial had industry co-sponsorship. We tabulated whether the study reported a positive, negative, or null result on the primary outcome variable and for total mortality.

    Results
    17 of 30 studies (57%) published prior to 2000 showed a significant benefit of intervention on the primary outcome in comparison to only 2 among the 25 (8%) trials published after 2000 (χ2=12.2,df= 1, p=0.0005). There has been no change in the proportion of trials that compared treatment to placebo versus active comparator. Industry co-sponsorship was unrelated to the probability of reporting a significant benefit. Pre-registration in clinical trials.gov was strongly associated with the trend toward null findings.

    Conclusions
    The number NHLBI trials reporting positive results declined after the year 2000. Prospective declaration of outcomes in RCTs, and the adoption of transparent reporting standards, as required by clinicaltrials.gov, may have contributed to the trend toward null findings.

    Full text
     
    LarsSG, Aug 2, 2022
    #1
    inox, Lilas, Hutan and 10 others like this.
  2. alktipping

    alktipping Senior Member (Voting Rights)

    Messages:
    1,294
    from my point of view null findings prove that in these instances this system is working as intended .
     
    alktipping, Aug 2, 2022
    #2
    inox, Lilas, Hutan and 2 others like this.
  3. Hutan

    Hutan Moderator Staff Member

    Messages:
    29,374
    Location:
    Aotearoa New Zealand
    Nice find, LarsSG.

    I think all patient charities should be demanding that all clinical trials for ME/CFS and Long Covid are pre-registered. They can start by ensuring that's the case with any studies that they fund or promote. They can lobby government agencies to adopt this as standard, both for studies funded by governments and any studies carried out by organisations receiving government funding such as universities. They can lobby high profile ME/CFS researchers to ensure all of their clinical trials are pre-registered.

    See here for example:
    The Institute for Neuro-immmune Medicine (Nancy Klimas is the director) of Nova Southeastern University is doing a study of a branded probiotic to treat ME/CFS. It has not been pre-registered.
    US: The Use of Directed Probiotics in ME/CFS
    It's not good enough. Pre-registration must be a necessary part of doing clinical trials. We've tolerated sloppy and biased research for long enough.

    I wonder if there are existing laws or guidelines about this.
     
    Hutan, Aug 3, 2022
    #3
    alktipping, Sean, cassava7 and 6 others like this.

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