Reinhardt, V., Reinhardt, A. 2000. Blood collection procedure of laboratory primates: A neglected variable in biomedical research. Journal of Applied Animal Welfare Science 3(4), 321-333.

A survey of 75 biomedical articles dealing with stress-dependent blood parameters in caged primates revealed that the conditions under which blood collection occurred were in most cases [72%] described either not at all or so haphazardly that it would be impossible to determine if humane handling procedures were used and basic principles of scientific methodology applied. These findings were unexpected because not only is there ample scientific evidence that stress-sensitive research data are influenced by traditional blood sampling procedures, but also that those data-biasing effects can be avoided. If dependent variables of the blood collection procedure are not controlled, data variability will increase thereby automatically also increasing the number of animals needed for statistical analysis. For ethical and scientific reasons, it was recommended that editors of biomedical journals should require that authors provide sufficient information of the blood collection - and when applicable also of the sedative injection - procedure to assure that the experiment was done with the smallest number of animals possible to achieve statistical significance, and that the investigation can be replicated reliably in another laboratory and the research data interpreted with reasonable accuracy.