Just How Useful Are Animal Studies To Human Health?

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Just How Useful Are Animal Studies To Human Health?

http://www.sciencedaily.com/releases/2006/12/061215090857.htm

Animal studies are of limited usefulness to human health because

they are of poor quality and their results often conflict with human

trials, argue researchers in a study online in the British Medical

Journal.

Before clinical trials are carried out, the safety and effectiveness

of new drugs are usually tested in animal models. Some believe,

however, that the results from animal trials are not applicable to

humans because of biological differences between the species.

So researchers compared treatment effects in animal models with

human clinical trials.

They used systematic reviews (impartial summaries of evidence from

many different studies) of human and animal trials to analyse the

effects of six drugs for conditions such as head injury, stroke and

osteoporosis.

Agreement between human and animal studies varied. For example,

corticosteroids did not show any benefit for treating head injury in

clinical trials but did show a benefit in animal models. Results

also differed for the drug tirilazad to treat stroke - data from

animal studies suggested a benefit but the clinical trials showed no

benefit and possible harm.

Some results did agree. For instance, bisphosphonates increased bone

mineral density in both clinical trials and animal studies, while

corticosteroids reduced neonatal respiratory distress syndrome in

animal studies and in clinical trials, although the data were

sparse.

Animal studies are generally of poor quality and lack agreement with

clinical trials, which limits their usefulness to human health, say

the authors. This discordance may be due to bias, random error, or

the failure of animal models to adequately represent clinical

disease.

Systematic reviews could help translate research findings from

animals to humans. They could also promote closer collaboration

between the research communities and encourage an interative

approach to improving the relevance of animal models to clinical

trial design, they conclude.