Trends in silicosis prevalence and the healthy worker effect among gold miners in South Africa: a prevalence study with follow up of employment status.
Trends in silicosis prevalence and the healthy worker effect among gold miners in South Africa: a prevalence study with follow up of employment status.
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DOI：
10.1186/s12889-015-2566-8
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发表时间：
2015-12-18
影响因子：
4.5
通讯作者：
Churchyard G
中科院分区：
文献类型：
--
作者：
Knight D;Ehrlich R;Fielding K;Jeffery H;Grant A;Churchyard G
鉴于矽肺和结核病之间的密切联系，了解南非金矿业矽肺流行病的流行病学是至关重要的，目前的举措，以控制矽肺和结核病在这一人群中，全球受影响最严重的之一。该研究的目的是将2004-2009年期间南非工作黑金矿工中硅肺患病率与之前的研究（包括尸检系列）进行比较，并分析硅肺和/或结核对退出就业的影响。由一名有经验的读片员（I）读取一组金矿工人的常规胸片，以检查是否有矽肺，并由一名受过B超训练的读片员（II）重新读取一部分胸片。使用了两种方法来呈现读数。此外，以矽肺基线状态和既往或活动性结核病作为预测因素，生存分析检查了2006-2011年期间因任何原因退出劳动力的概率。读片员I读取了11557张胸片，读片员II重新读取了841张。总体而言，矽肺患病率（ILO ≥1/0：5.7和6.2%，取决于阅片者方法）与1984年一项大型研究中发现的年龄校正患病率（5.0%）相似。当比较仅限于先前在2000年研究的单个矿井时，表明其中一种阅读方法的患病率下降（ILO ≥1/1）（持续时间调整后为20.5%，当前研究为13.0%）。这些发现与这一时期硅肺尸检患病率长期上升的趋势不一致。总体而言，相对于两种疾病均未患病的矿工，基线矽肺患者在随访期间退出工作的调整后风险比为1.54 [95%置信区间（CI）1.17，2.04]，结核病患者为1.71（95% CI 1.51，1.94），合并疾病患者为1.53（95% CI 1.20，1.96）。这项研究发现，a）1984年至2004年至2009年期间，南非金矿业黑人矿工的总体矽肺患病率没有显著下降，B）最近一个矿井的患病率可能有所下降。在没有证据表明1980年代至2000年代期间可吸入二氧化硅浓度下降的情况下，发现的趋势可能是由于健康工人的幸存者效应，这种效应可能正在加速。本文的在线版本（doi：10.1186/s12889-015-2566-8）包含补充材料，可供授权用户使用。
Given the intimate association between silicosis and tuberculosis, understanding the epidemiology of the South African gold mining industry silicosis epidemic is essential to current initiatives to control both silicosis and tuberculosis in this population, one of the most heavily affected globally. The study’s objectives were to compare the prevalence of silicosis among working black gold miners in South Africa during 2004–2009 to that of previous studies, including autopsy series, and to analyse the influence of silicosis and/or tuberculosis on exiting employment. Routine chest radiographs from a cohort of gold miners were read for silicosis by an experienced reader (I), and a subset re-read by a B-trained reader (II). Two methods of presenting the readings were used. Additionally, with baseline status of silicosis and previous or active tuberculosis as predictors, survival analysis examined the probability of exiting the workforce for any reason during 2006–2011. Reader I read 11 557 chest radiographs and reader II re-read 841. Overall, silicosis prevalence (ILO ≥1/0: 5.7 and 6.2 % depending on reader method) was similar to the age adjusted prevalence found in a large study in 1984 (5.0 %). When comparison was restricted to a single mine shaft previously studied in 2000, a decline in prevalence (ILO ≥1/1) was suggested for one of the reading methods (duration adjusted 20.5 % vs. 13.0 % in the current study). These findings are discordant with a long-term rising autopsy prevalence of silicosis over this period. Overall, relative to miners with neither disease, the adjusted hazard ratio for exiting employment during the follow-up period was 1.54 for baseline silicosis [95 % confidence interval (CI) 1.17, 2.04], 1.71 for tuberculosis (95 % CI 1.51, 1.94) and 1.53 for combined disease (95 % CI 1.20, 1.96). This study found, a) there was no significant decline in overall silicosis prevalence among working black miners in the South African gold mining industry between 1984 and 2004–2009, and b) a possible decline at one mine shaft more recently. In the absence of evidence of declining respirable silica concentrations between the 1980s and 2000s, the trends found are plausibly due to a healthy worker survivor effect, which may be accelerating. The online version of this article (doi:10.1186/s12889-015-2566-8) contains supplementary material, which is available to authorized users.