Ramachandran Gurumurthy, Banerjee Sudipto, Vincent James H
Division of Environmental and Occupational Health, School of Public Health, University of Minnesota, Minneapolis, MN 55455, USA.
Ann Occup Hyg. 2003 Aug;47(6):461-75. doi: 10.1093/annhyg/meg066.
In many situations characterized by sparse data, occupational hygienists have used subjective judgments that are claimed to be derived from their experience and knowledge. While this practice is widespread, there has been no systematic study of 'expert judgment' or the 'art' of occupational hygiene. Indeed, there is a need to address the question of whether there is such a thing as 'expert opinion' in occupational hygiene that is broadly shared by practicing professionals. This research, employing 11 experts who estimate an exposure parameter (the percentages of four nickel species) in 12 workplaces in a nickel primary production industry, provides a large dataset from which useful inferences can be drawn about the quality of expert judgments and the variability among the experts. A well-designed questionnaire that provided succinct information about the processes and baseline data served to calibrate the experts. The Bayesian framework has been used in this work to develop posterior means and standard deviations of the percentages of the four nickel species in the 12 workplaces of interest in the company. These estimates of the nickel speciation are at least as precise as--and most of the time more precise than--those provided by the sparse measurement data. There was a very high degree of agreement among the experts. A majority of the experts agreed among themselves 92% of the time, while almost two-thirds agreed 73% of the time. This, coupled with the fact that the experts came from varied backgrounds, seems to suggest that there is indeed some broad body of specialized knowledge that the experts are drawing on to reach similar judgments. It also seems that one type of expert is not necessarily any better than any other kind, and expertise does not necessarily require intimate familiarity with the workplace. In this example, the expert judgment exercise has indeed enhanced the quality of our knowledge of the exposure 'fingerprints' for the nickel industry workplaces studied and the combination of expert judgment and sparse data is better than the sparse data alone. For occupational hygiene exposure assessment, our experience suggests that such expert judgment methods can provide a cost-effective means to improve and refine information about workplace hazards. However, more study is warranted for situations where the domain of the quantity of interest has a much wider range of values, e.g. actual exposure values.
在许多以数据稀疏为特征的情况下，职业卫生学家会运用主观判断，这些判断据称源于他们的经验和知识。尽管这种做法很普遍，但尚未有对“专家判断”或职业卫生“技艺”的系统研究。事实上，有必要探讨在职业卫生领域是否存在被执业专业人员广泛认同的“专家意见”这一问题。本研究邀请了11位专家对镍初级生产行业的12个工作场所中的一个暴露参数（四种镍物种的百分比）进行估算，从而提供了一个大型数据集，据此可以就专家判断的质量以及专家之间的变异性得出有用的推论。一份精心设计的问卷提供了有关流程和基线数据的简洁信息，用于校准专家。本研究采用贝叶斯框架来得出该公司12个相关工作场所中四种镍物种百分比的后验均值和标准差。这些镍形态的估算至少与稀疏测量数据提供的估算一样精确，而且在大多数情况下比其更精确。专家之间达成了高度一致。大多数专家在92%的时间里彼此达成一致，而近三分之二的专家在73%的时间里达成一致。这一点，再加上专家来自不同背景这一事实，似乎表明确实存在某种广泛的专业知识体系，专家们据此得出类似的判断。似乎一种类型的专家并不一定比其他类型的专家更出色，而且专业知识并不一定要求对工作场所非常熟悉。在这个例子中，专家判断活动确实提高了我们对所研究的镍行业工作场所暴露“指纹”的了解质量，并且专家判断与稀疏数据的结合比单独的稀疏数据更好。对于职业卫生暴露评估，我们的经验表明，这种专家判断方法可以提供一种经济有效的手段来改进和完善有关工作场所危害的信息。然而，对于感兴趣的数量范围更广的情况，例如实际暴露值，还需要进行更多研究。
