Friesen Melissa C, Davies Hugh W, Ostry Aleck, Teschke Kay, Demers Paul A
School of Occupational and Environmental Hygiene, University of British Columbia, Vancouver, Canada V6T 1Z3.
Int Arch Occup Environ Health. 2008 Jul;81(7):837-44. doi: 10.1007/s00420-007-0274-0. Epub 2007 Oct 31.
Expert-judgment has frequently been used to assess quantitative exposure for epidemiologic studies, but accuracy varies widely dependent on the type of exposure and the availability of measurements to anchor estimates. There is limited empirical evidence of the sensitivity of exposure-response relationships to expert- versus measurement-based exposure assessment strategies. We examined the sensitivity of the exposure-response relationship between occupational noise exposure and acute myocardial infarction (AMI) mortality using both expert- and measurement-based occupational noise estimates in a retrospective cohort study of sawmill workers (n = 27,499).
Expert-based noise estimates were evaluated by four industry experts who rated 54 sawmill jobs on a four-point scale. Measurement-based noise estimates were derived from statistical models that accounted for job, mill, and time period differences. The model-based estimates were adjusted to account for the use of hearing protective devices (HPD). We examined the shape, goodness of fit, precision, and expected versus observed attenuation of the exposure-response relationships between cumulative noise exposure and AMI mortality (910 deaths).
The correlations between the expert-based and the measurement-based unadjusted and HPD-adjusted cumulative noise estimates were 0.81 and 0.57, respectively. The HPD-adjusted model-based estimates provided the most precise exposure-response relationship; no associations were observed with the unadjusted or expert-based noise estimates. In a subgroup with minimal HPD use (n = 8,700, 520 deaths), the expert- and model-based noise estimates resulted in similar relative risks; the model-based approach was 12% more precise.
The measurement-based approach was more precise, as expected, but experts were reasonably able to rank occupational noise exposures. The experts' assessment was, however, unable to account for HPD use, which made a substantial contribution to exposure misclassification in this study. The experts' noise estimates would be more useful for risk assessment if they were calibrated against units of noise exposure.
专家判断经常被用于评估流行病学研究中的定量暴露，但准确性因暴露类型和用于锚定估计值的测量数据的可用性不同而有很大差异。关于暴露-反应关系对基于专家和基于测量的暴露评估策略的敏感性，实证证据有限。在一项对锯木厂工人（n = 27,499）的回顾性队列研究中，我们使用基于专家和基于测量的职业噪声估计值，研究了职业噪声暴露与急性心肌梗死（AMI）死亡率之间暴露-反应关系的敏感性。
四位行业专家对54个锯木厂工作岗位进行了四点量表评分，以此评估基于专家的噪声估计值。基于测量的噪声估计值来自于统计模型，该模型考虑了工作岗位、工厂和时间段差异。基于模型的估计值进行了调整，以考虑听力保护装置（HPD）的使用情况。我们研究了累积噪声暴露与AMI死亡率（910例死亡）之间暴露-反应关系的形状、拟合优度、精度以及预期与观察到的衰减情况。
基于专家的未调整和经HPD调整的累积噪声估计值与基于测量的估计值之间的相关性分别为0.81和0.57。经HPD调整的基于模型的估计值提供了最精确的暴露-反应关系；未调整的或基于专家的噪声估计值未观察到关联。在HPD使用最少的亚组（n = 8,700，520例死亡）中，基于专家和基于模型的噪声估计值导致了相似的相对风险；基于模型的方法精度高12%。
正如预期的那样，基于测量的方法更精确，但专家能够合理地对职业噪声暴露进行排序。然而，专家的评估无法考虑HPD的使用情况，这在本研究中对暴露错误分类有很大影响。如果根据噪声暴露单位对专家的噪声估计值进行校准，它们对风险评估将更有用。
