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THE Government has made much of the importance of scientific advice and an evidence-based approach to policy making, and rightly so. However, difficulties can arise when, as is often the case, the science is less than clear cut, or scientists disagree about the findings. History is littered with examples, but the problem has again come to the fore in a high-level spat over the conclusions that can be drawn from the randomised badger culling trial.
The Independent Scientific Group on Cattle tb (isg), which was set up by the Government in 1998 to oversee the trial, reported on the results in June this year and, while noting that badgers were ‘clearly a source of cattle tb’, was fairly unequivocal in its conclusions. Badger culling, it said, could not meaningfully contribute to the control of bovine tb in cattle in Britain. However, rigorous application of heightened control measures directly targeting cattle would reverse the year-on-year increase in the incidence of cattle tb and halt the geographical spread of the disease (see VR, June 23, 2007, vol 160, pp 853, 854-856).
The isg may have been clear about the results but the situation was complicated last month by the publication of a report from the Government's chief scientific adviser, Sir David King, who, having considered the report with a group of five experts, had essentially drawn the opposite conclusion (see VR, October 27, 2007, vol 161, p 574). The chief scientific adviser had been asked to comment on the report by the then Secretary of State at defra, Mr David Miliband, and had submitted his observations to defra in July. Among his conclusions was that ‘reducing the density of badgers in those areas of Britain where there is a significant level of tb in cattle reduces the incidence of tb in cattle in the same area’ and that ‘removal of badgers should take place alongside the continued application of controls in cattle’. In a debate which has been dogged by controversy from the start, the chief scientific adviser's intervention has been welcomed by those who believe that culling badgers will help control bovine tb in cattle, and greeted with dismay by those who do not. The bva, which has argued for some time that the problem of bovine tb in cattle cannot properly be addressed without also addressing the problem in wildlife, has welcomed his report.
The House of Commons Environment, Food and Rural Affairs Committee (efracom) is currently taking evidence in relation to the isg's report and, giving evidence last week, both Sir David King and Professor John Bourne, the isg's chairman, robustly defended their positions. Meanwhile, in a letter in this issue of The Veterinary Record, Professor Bourne responds to questions about the culling trial that have been raised in this journal (see p 633). Once again, there is a danger of the debate becoming polarised, among scientists as well as others, which is not helpful for those seeking practical solutions to what is a real and worsening problem.
Part of the difficulty here is that the uncertainties and long-term nature of science can be hard to reconcile with the short-term realities of politics. As Sir David King remarked in his report, ‘While [the] evidence may not be as conclusive as one might like, further trials are unlikely to significantly improve the certainty in the evidence base. Strong action needs to be taken now to reverse the upward trend of this important disease. Decisions therefore need to be taken on badger removal in the light of the existing scientific evidence, in spite of its uncertainties.’
The importance — and difficulties — of incorporating science into political decision making were highlighted last November in an excellent report from the House of Commons Science and Technology Committee (see VR, November 25, 2006, vol 159, p 725). The Science and Technology Committee's report made clear that there was considerable scope for strengthening the arrangements for ensuring an effective scientific advisory system in government departments, citing defra as ‘an exemplar of good practice’ in this area. Like earlier reports, such as the report of the bse Inquiry in 2000 or the reports of the inquiries into the 2001 foot-and-mouth disease outbreak, it also drew attention to the need for more transparency in decision making: given that science is rarely black and white, there is a continuing need to separate facts from opinion, and to make clear where the science stops and policies begin.
It is not clear at this stage what the efracom will make of the scientific arguments about bovine tb, or the extent to which its conclusions might influence government policy. What is clear, however, is that, after a wait of nearly 10 years, it is time ministers came to a decision.