Ecoclimber
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Hirst JA, Howick J, Aronson JK, Roberts N, Perera R, Koshiaris C, Heneghan C.The Need for Randomization in Animal Trials: An Overview of Systematic Reviews.PLoS One. 2014;9(6):e98856.
BACKGROUND AND OBJECTIVES:
Randomization, allocation concealment, and blind outcome assessment have been shown to reduce bias in human studies. Authors from the Collaborative Approach to Meta Analysis and Review of Animal Data from Experimental Studies (CAMARADES) collaboration recently found that these features protect against bias in animal stroke studies. We extended the scope the work from CAMARADES to include investigations of treatments for any condition.
METHODS:
We conducted an overview of systematic reviews. We searched Medline and Embase for systematic reviews of animal studies testing any intervention (against any control) and we included any disease area and outcome. We included reviews comparing randomized versus not randomized (but otherwise controlled), concealed versus unconcealed treatment allocation, or blinded versus unblinded outcome assessment.
RESULTS:
Thirty-one systematic reviews met our inclusion criteria: 20 investigated treatments for experimental stroke, 4 reviews investigated treatments for spinal cord diseases, while 1 review each investigated treatments for bone cancer, intracerebral hemorrhage, glioma, multiple sclerosis, Parkinson's disease, and treatments used in emergency medicine. In our sample 29% of studies reported randomization, 15% of studies reported allocation concealment, and 35% of studies reported blinded outcome assessment. We pooled the results in a meta-analysis, and in our primary analysis found that failure to randomize significantly increased effect sizes, whereas allocation concealment and blinding did not. In our secondary analyses we found that randomization, allocation concealment, and blinding reduced effect sizes, especially where outcomes were subjective.
CONCLUSIONS:
Our study demonstrates the need for randomization, allocation concealment, and blind outcome assessment in animal research across a wide range of outcomes and disease areas. Since human studies are often justified based on results from animal studies, our results suggest that unduly biased animal studies should not be allowed to constitute part of the rationale for human trials.
From Mouse Doctor:
If animal studies are not run like clinical trials in humans, they tend to over estimate the treatment effect, whether it is MS related research or other not.. Randomisation means randomly associating people or animals into treatments in trials. With humans they are genetically different different ages, sexes etc, etc and live and eat differently from one another and randomisation will take account of this.
In animal studies this appears to make a difference, which is interesting as the animals are often genetically identical and come from the same place and eat the same stuff and live in the same space and their cages may only be a few centimetres from each other. Do people subliminally pick on the animal that is different, or do they load studies with ropey-looking animals on their way to disease whilst leaving the healthly looking ones for drug.
Animals studies clearly lack on quality of reporting and may be poor experimental design. Before a company ploughs a few million into developing drugs they tend to repeat experiments independently and so the dogey stuff that litters the literature may fall by the way-side.
Researchers need to up their game
I concur. Permission to repost
BACKGROUND AND OBJECTIVES:
Randomization, allocation concealment, and blind outcome assessment have been shown to reduce bias in human studies. Authors from the Collaborative Approach to Meta Analysis and Review of Animal Data from Experimental Studies (CAMARADES) collaboration recently found that these features protect against bias in animal stroke studies. We extended the scope the work from CAMARADES to include investigations of treatments for any condition.
METHODS:
We conducted an overview of systematic reviews. We searched Medline and Embase for systematic reviews of animal studies testing any intervention (against any control) and we included any disease area and outcome. We included reviews comparing randomized versus not randomized (but otherwise controlled), concealed versus unconcealed treatment allocation, or blinded versus unblinded outcome assessment.
RESULTS:
Thirty-one systematic reviews met our inclusion criteria: 20 investigated treatments for experimental stroke, 4 reviews investigated treatments for spinal cord diseases, while 1 review each investigated treatments for bone cancer, intracerebral hemorrhage, glioma, multiple sclerosis, Parkinson's disease, and treatments used in emergency medicine. In our sample 29% of studies reported randomization, 15% of studies reported allocation concealment, and 35% of studies reported blinded outcome assessment. We pooled the results in a meta-analysis, and in our primary analysis found that failure to randomize significantly increased effect sizes, whereas allocation concealment and blinding did not. In our secondary analyses we found that randomization, allocation concealment, and blinding reduced effect sizes, especially where outcomes were subjective.
CONCLUSIONS:
Our study demonstrates the need for randomization, allocation concealment, and blind outcome assessment in animal research across a wide range of outcomes and disease areas. Since human studies are often justified based on results from animal studies, our results suggest that unduly biased animal studies should not be allowed to constitute part of the rationale for human trials.
From Mouse Doctor:
If animal studies are not run like clinical trials in humans, they tend to over estimate the treatment effect, whether it is MS related research or other not.. Randomisation means randomly associating people or animals into treatments in trials. With humans they are genetically different different ages, sexes etc, etc and live and eat differently from one another and randomisation will take account of this.
In animal studies this appears to make a difference, which is interesting as the animals are often genetically identical and come from the same place and eat the same stuff and live in the same space and their cages may only be a few centimetres from each other. Do people subliminally pick on the animal that is different, or do they load studies with ropey-looking animals on their way to disease whilst leaving the healthly looking ones for drug.
Animals studies clearly lack on quality of reporting and may be poor experimental design. Before a company ploughs a few million into developing drugs they tend to repeat experiments independently and so the dogey stuff that litters the literature may fall by the way-side.
Researchers need to up their game
I concur. Permission to repost