A guest post from加里·比洛塔（Gary Bilotta），布莱顿大学的高级讲师，他在其中讨论了他的recent articlepublished in the journal环境证据。

从badge和牛结核病，农药和传粉媒介到页岩气和污染，环境政策可以吸引所有方面的公众和专家的广泛关注。即使专家也对环境主题有自己的看法，决策者也需要将这些观点考虑在内。政策实施是多维的，正确包括选举，道德，文化，实践，法律和经济考虑与科学证据一起。但是，如果决策者希望发现有关给定主题的证据基础，他们必须尝试探讨个人偏见。他们还必须尝试确定科学证据本身的偏见，作为评估证据质量的一部分。

Though assessments of study quality can be made informally using expert judgement, we know that experts in a particular area frequently have pre-formed opinions that can bias their assessments (Burgman等。, 2011;Oxman and Guyatt，1993）。为了减少审阅者偏见的潜力，并确保证据综合的发现是透明且可重复的，例如Cochrane Collaboration, the坎贝尔合作，和Collaboration for Environmental Evidence,建议正式的质量评价工具,recognising that the merits of a formal approach outweigh the drawbacks. Could similar assessment tools be used for environmental policy-making?

大约有300个正式的学习质量评估工具是在文献中确定。它们旨在提供一种使用逐项标准，在质量清单的情况下，或在尺度上进行定量的情况，可以客观地评估研究的整体质量。

In the healthcare field, a meta-analysis of 17 trials comparing the effectiveness of low-molecular-weight heparin (LMWH) with standard heparin for two treatments for prevention of post-operative thrombosis, trials that were identified as ‘high quality’ by some of the 25 quality scales interrogated, indicated that LWMH was not superior to standard heparin, but trials identified as ‘high quality’ by other scales led to theopposite conclusions。It is therefore very important to consider carefully, the choice of quality assessment tool to be used in evidence syntheses.

在我的文章中，由Defra的首席科学顾问Ian Boyd教授和伦敦大学学院的Alice Milner博士合着，本周在环境证据, we argue that quality assessment tools should have demonstrable link with what they purport to measure, facilitate inter-reviewer agreement, be applicable across study designs, and be quick and easy to use.

The Cochrane Collaboration, who are internationally renowned for their systematic reviews in healthcare, recently developed an approach to quality assessment that satisfies these four criteria. Before 2008, the Cochrane Collaboration used a variety of quality assessment tools, mainlychecklists in their systematic reviews。Acknowledging inconsistency in using different tools to assess the same studies, and越来越多的批评of many of these tools , in 2005 the Cochrane Collaboration’s Methods Groups, including statisticians, epidemiologists, and review authors, embarked on developing a new evidence-based strategy for assessing the quality of studies. The resultant approach is now used by the WHO among twenty other organisations internationally.

Our article investigates the extent to which this best practice approach could be useful for assessing the quality of evidence from environmental science. We believe that the feasibility of this has been demonstrated in a number of existing systematic reviews on environmental topics published by the Collaboration for Environmental Evidence. It is not difficult to imagine that the approach could be adapted and applied routinely, as part of the quality assessment of environmental science studies cited in evidence syntheses, and we propose a pilot version of the modified approach for this purpose.

‘Learning by doing’ with the pilot versions of these tools is exactly how healthcare refined its own tools. Better formal quality assessment will improve how science is used to inform policy decisions, helping policy-makers to navigate personal biases while identifying biases and weaknesses in primary studies that affect their reliability. Better formal quality assessment should also improve the quality of policy-orientated environmental science in the future.