Berhane Kiros, Hauptmann Michael, Langholz Bryan
Department of Preventive Medicine, Keck School of Medicine, University of Southern California, 1540 Alcazar St. CHP-220, Los Angeles, CA 90089-9011, USA.
Stat Med. 2008 Nov 20;27(26):5484-96. doi: 10.1002/sim.3354.
An adequate depiction of exposure-time-response relationships is important in assessing public health implications of an occupational or environmental exposure. Recent advances have focused on flexible modeling of the overall shape of latency. Methods are needed to allow for varying shapes of latency under different exposure profiles. A tensor product spline model is proposed for describing exposure-response relationships for protracted time-dependent occupational exposure histories in epidemiologic studies. The methods use flexible multi-dimensional techniques to jointly model age, latency and exposure-response effects. In analyzing data from the Colorado Plateau Uranium Miners cohort, a model that allows for varying exposure-dependent latency shapes is found to be superior to models that only allowed for an overall latency curve. Specifically, the model suggests that, at low exposure levels risk increased at short latencies followed by a slow decline for longer latency periods. On the other hand, risk was higher but did not change much by latency for higher exposure levels. The proposed methodology has the advantage of allowing for latency functions that vary by exposure levels and, conversely, exposure-response relationships that are influenced by the latency structure.
充分描述暴露时间反应关系对于评估职业或环境暴露对公众健康的影响至关重要。最近的进展集中在对潜伏期总体形状的灵活建模上。需要一些方法来考虑不同暴露情况潜伏期的不同形状。本文提出了一种张量积样条模型，用于描述流行病学研究中长期时间依赖性职业暴露史的暴露反应关系。这些方法使用灵活的多维技术，来共同模拟年龄、潜伏期和暴露反应效应。在分析科罗拉多高原铀矿矿工队列的数据时，发现一个允许不同暴露依赖潜伏期形状的模型优于仅允许总体潜伏期曲线的模型。具体而言，该模型表明，在低暴露水平下，风险在短潜伏期时增加，随后在较长潜伏期内缓慢下降。另一方面，在高暴露水平下，风险更高，但随潜伏期变化不大。所提出的方法具有允许潜伏期函数随暴露水平变化的优点，反之亦然，暴露反应关系受潜伏期结构影响。
