Reduction

Russell & Burch book cover

Michael Balls

Reduction should be the easiest of the Three Rs to achieve,
but it will not happen without a revolution in education
and training on the design and analysis of animal experiments

I have read The Principles of Humane Experimental Technique1 many times, but I have to confess that I have always had difficulty in understanding much of Russell and Burch’s chapter on Reduction. They saw this R as “one of the most obviously, immediately, and universally advantageous in terms of efficiency” of all the modes of progress. It is, they suggested, “desirable in any procedure, however humane, which employs large numbers of animals in one laboratory”, and is achievable “by the right choice of strategies in the planning and performance of whole lines of research”.

The main issue, as discussed “in a searching essay” by Charles Hume,2 founder of UFAW and initiator of the Three Rs project, is “choosing between trial and error on a grand scale and deductively inspired research”. The first approach has been used to test “a constant and huge stream of chemical substances” randomly directed at major medical targets, such as cancer. The second “may take the form of testing deductions from well and consciously formulated hypotheses, or it may involve working from hunches”.
Russell and Burch suggested two main conclusions: that, “wherever it is possible directly to compare guided and random research, the former is seen to be the most efficient”; and that, where trial and error methods are used, “it is desirable in terms of humanity, cost, and effort, for the trial and error to be applied to replacement methods or subjects”.

That is all very sound and reasonable, but it is the following 26 pages of the book chapter which are somewhat overwhelming. This is where Russell focused intensely on his particular interest in the problem of variance and how it could be tackled, stating that “Relative accuracy depends on the size of the sample, the extent to which individuals of the species vary [e.g. in response to a drug] and the efficiency and design of [the] experiment”, and that the key to reducing the effects of this variance is “the ingenious design of experiments”.

Statistical advice is important at the outset, since “every time any particle of statistical method is properly used, fewer animals are employed than would otherwise have been necessary”. However, the nature and quality of such advice are variable, leading to controversies, some of which are still unresolved today. One example is toxicity testing, where Hume said that “the fallacy consists in supposing that, in order to obtain a broad inductive basis, a heterogeneous stock [of animals] should be used”.

This, he said, is like estimating the value of a pocketful of coins “by counting the coins as coins, without sorting them according to their different values”. The proper procedure is “to use several different homogeneous samples”, and “to allow for the variance between samples”. This particular controversy continues today, as Michael Festing3 pointed out in an issue of ATLA on Reduction, in a special volume to mark FRAME’s 40th anniversary.

It is particularly disappointing that, while the numbers of procedures applied to laboratory animals fell steadily during the 1980s and 1990s, they have increased year on year since then. This was almost exclusively attributed to the breeding and use of genetically-modified animals and animals with harmful genetic defects, but in the UK in 2011, the larger increase was on procedures on normal animals, and especially for fundamental research on cancer, immunology and physiology.4

Another cause of the failure to achieve reduction is that scientists are not sufficiently well trained in how to perform experiments and how to analyse the data they obtain from them. Of course, this problem is not confined to experiments on animals, but applies to other kinds of experiment as well. Russell and Burch were aware of this problem, when, referring to the choice of strategies in planning and performing experiments, they said that “most of us settle early in our research career on some strategy that appears to suit our temperament, and are liable never to raise the question again”. That is nothing short of shocking, as it takes into account neither the scientific demands of the purpose of the experiment, nor, in the case of animal experimentation, the costs to the animals involved. I remember being deeply disturbed, many years ago, on learning that rhesus monkeys were kept in primate chairs with head restraint for up to six hours a day, five days a week, with electrodes implanted into their brains. They would have been there for longer, but the scientists involved didn’t like working in the evenings or at weekends.

The lack of adequate education and training in the design and analysis of experiments has long been a matter of concern to a small number of people and organisations. FRAME has been successfully running courses for some time,5 but the numbers of participants involved can only be small in relation to the total number of animal users.

Michael Festing, who I have always regarded as the natural successor to William Russell on these issues, has contributed an excellent and challenging comment to this issue of PiLAS.6 He emphasises that animal experiments should not only be well designed, but also repeatable, if the use of the animals is to be justifiable and the results are to lead to reliable improvements in human health. Unfortunately, this is often not possible, as illustrated by three reviews he cites which show the magnitude of the problem in research on oncology, amyotrophic lateral sclerosis and drug development.

The solution to the problem lies partly with those who fund research and the editors of the journals that publish its outcomes, but it is primarily the responsibility of the research scientists themselves and those in their institutions who evaluate their progress as professionals. The laws and regulations which apply to the use of animals for scientific purposes also have an important role to play, as has been recognised in various countries in the past, including The Netherlands and the UK. In the EU, it can be expected that Directive 2010/63/EU,7 which came into force at the beginning of 2013, will have a significant impact in the 27 Member States, as it specifically refers to education and training in Article 23, Competence of personnel:

2. The staff shall be adequately educated and trained before they perform any of the following functions: (a) carrying out procedures on animals; (b) designing procedures and projects; (c) taking care of animals; or (d) killing animals.

Persons carrying out the functions referred to in point (b) shall have received instruction in a scientific discipline relevant to the work beingundertaken and shall have species-specific knowledge. Staff carrying out functions referred to in points (a), (c) or (d) shall be supervised in the performance of their tasks until they have demonstrated the requisite competence. Member States shall ensure, through authorisation or by other means, that the requirements laid down in this paragraph are fulfilled.

3. Member States shall publish [on the basis of the elements set out in Annex V] minimum requirements with regard to education and training and the requirements for obtaining, maintaining and demonstrating requisite competence for the functions set out in paragraph 2.

The Directive also requires that Member States shall ensure that the number of animals used in projects is reduced to a minimum without compromising the objectives of the project. If this requirement is strictly enforced and competently and sincerely adhered to, the steady upward trend in the numbers of animals used should be reversed and the number of procedures conducted progressively reduced, at least in the EU, in line with Russell and Burch’s central Three Rs thesis that “the humanest possible treatment of laboratory animals, far from being an obstacle, is actually a prerequisite for successful animal experiments”.

References and Note
1 Russell, W.M.S. & Burch, R.L. (1959). The Principles of Humane Experimental Technique, xiv + 238pp. London, UK: Methuen.
2 Hume, C.W. (1957). The strategy and tactics of experimentation. The Lancet, 23 November, 1049–1052.
3 Festing, M. (2009). Fifty years after Russell and Burch, toxicologists continue to ignore variation in their test animals. ATLA 37, 1–5.
4 Hudson-Shore, M. (2012). Statistics of Scientific Procedures on Living Animals 2011: Another increase in animal experimentation, but is there a shift in emphasis? ATLA 40, 211–219.
5 Hudson, M. & Howard, B. (2009). The FRAME Reduction Steering Committee: Reflections on a decade devoted to reducing animal use in biomedical science. ATLA 37, 23–26.
6 Festing, M. (2013). We are not born knowing how to design and analyse scientific experiments. ATLA 41, P19–P21.
7 Anon. (2010). Directive 2010/63/EU of the European Parliament and of the Council of 22 September 2010 on the protection of animals used for scientific purposes. Official Journal of the European Union L276, 20.10.2010, 33–79.

The Principles of Humane Experimental Technique is now out of print, but the full text can be found at http://altweb.jhsph.edu/pubs/books/humane_exp/het -toc. An abridged version, The Three Rs and the Humanity Criterion, by Michael Balls (2009), can be obtained from FRAME.

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