Many of the studies that use animals to model human diseases are too small and too prone to bias to be trusted, says Malcolm Macleod, author of the article titled "Why animal research needs to improve".
"...The most reliable animal studies are those that: use randomization to eliminate systematic differences between treatment groups; induce the condition under investigation without knowledge of whether or not the animal will get the drug of interest; and assess the outcome in a blinded fashion. Studies that do not report these measures are much more likely to overstate the efficacy of interventions. Unfortunately, at best one in three publications follows these basic protections against bias. This suggests that authors, reviewers and editors accord them little importance..."
To read more from the article, follow the "read source" link above.