“Where Is the Evidence That Animal Research Benefits Humans?”, 2004-02-28 (; similar):
Much animal research into potential treatments for humans is wasted because it is poorly conducted and not evaluated through systematic reviews.
…We searched MEDLINE to identify published systematic reviews of animal experiments (see
bmj.comfor the search strategy). The search identified 277 possible papers, of which 22 were reports of systematic reviews. We are also aware of one recently published study and two unpublished studies, bringing the total to 25. Three further studies are in progress (M Macleod, personal communication). Seven of the 25 papers were systematic reviews of animal studies that had been conducted to find out how the animal research had informed the clinical research. Two of these reported on the same group of studies, giving six reviews in this category. A further 10 papers were systematic reviews of animal studies conducted to assess the evidence for proceeding to clinical trials or to establish an evidence base. 8 systematically reviewed both the animal and human studies in a particular field, again before clinical trials had taken place. We focus on the 6 studies in the first category because these shed the most light on the contribution that animal research makes to clinical medicine.…The clinical trials of nimodipine and low level laser therapy were conducted concurrently with the animal studies, while the clinical trials of fluid resuscitation, thrombolytic therapy, and endothelin receptor blockade went ahead despite evidence of harm from the animal studies. This suggests that the animal data were regarded as irrelevant, calling into question why the studies were done in the first place and seriously undermining the principle that animal experiments are necessary to inform clinical medicine.
Furthermore, many of the existing animal experiments were poorly designed…Although randomization and blinding are accepted as standard in clinical trials, no such standards exist for animal studies. Bebarta et al found that animal studies that did not report randomization and blinding were more likely to report a treatment effect than studies that used these methods. The box summarises further potential methodological problems.
…Summary points:
The value of animal research into potential human treatments needs urgent rigorous evaluation
Systematic reviews can provide important insights into the validity of animal research
The few existing reviews have highlighted deficiencies such as animal and clinical trials being conducted simultaneously
Many animal studies were of poor methodological quality
Systematic reviews should become routine to ensure the best use of existing animal data as well as improve the estimates of effect from animal experiments