Sadhra Steven, Kurmi Om P, Sadhra Sandeep S, Lam Kin Bong Hubert, Ayres Jon G
Institute of Occupational and Environmental Medicine, University of Birmingham, Edgbaston, Birmingham.
Nuffield Department of Population Health, Clinical Trial Service Unit and Epidemiological Studies Unit, University of Oxford, Oxford, UK.
Int J Chron Obstruct Pulmon Dis. 2017 Feb 22;12:725-734. doi: 10.2147/COPD.S125980. eCollection 2017.
The association between occupational exposure and COPD reported previously has mostly been derived from studies relying on self-reported exposure to vapors, gases, dust, or fumes (VGDF), which could be subjective and prone to biases. The aim of this study was to assess the strength of association between exposure and COPD from studies that derived exposure by job exposure matrices (JEMs).
A systematic search of JEM-based occupational COPD studies published between 1980 and 2015 was conducted in PubMed and EMBASE, followed by meta-analysis. Meta-analysis was performed using a random-effects model, with results presented as a pooled effect estimate with 95% confidence intervals (CIs). The quality of study (risk of bias and confounding) was assessed by 13 RTI questionnaires. Heterogeneity between studies and its possible sources were assessed by Egger test and meta-regression, respectively.
In all, 61 studies were identified and 29 were included in the meta-analysis. Based on JEM-based studies, there was 22% (pooled odds ratio =1.22; 95% CI 1.18-1.27) increased risk of COPD among those exposed to airborne pollutants arising from occupation. Comparatively, higher risk estimates were obtained for general populations JEMs (based on expert consensus) than workplace-based JEM were derived using measured exposure data (1.26; 1.20-1.33 vs 1.14; 1.10-1.19). Higher risk estimates were also obtained for self-reported exposure to VGDF than JEMs-based exposure to VGDF (1.91; 1.72-2.13 vs 1.10; 1.06-1.24). Dusts, particularly biological dusts (1.33; 1.17-1.51), had the highest risk estimates for COPD. Although the majority of occupational COPD studies focus on dusty environments, no difference in risk estimates was found for the common forms of occupational airborne pollutants.
Our findings highlight the need to interpret previous studies with caution as self-reported exposure to VGDF may have overestimated the risk of occupational COPD.
先前报道的职业暴露与慢性阻塞性肺疾病（COPD）之间的关联大多来自依赖自我报告的蒸气、气体、粉尘或烟雾（VGDF）暴露的研究，这可能具有主观性且容易产生偏差。本研究的目的是评估通过工作暴露矩阵（JEMs）得出暴露情况的研究中暴露与COPD之间的关联强度。
在PubMed和EMBASE中对1980年至2015年间发表的基于JEM的职业性COPD研究进行系统检索，随后进行荟萃分析。使用随机效应模型进行荟萃分析，结果以合并效应估计值及95%置信区间（CIs）表示。通过13份RTI问卷评估研究质量（偏倚风险和混杂因素）。分别通过Egger检验和荟萃回归评估研究之间的异质性及其可能来源。
总共识别出61项研究，其中29项纳入荟萃分析。基于JEM的研究表明，职业性接触空气传播污染物的人群患COPD的风险增加22%（合并比值比=1.22；95%CI 1.18 - 1.27）。相比之下，基于专家共识的一般人群JEMs（1.26；1.20 - 1.33）的风险估计值高于基于实测暴露数据的工作场所JEMs（1.14；1.10 - 1.19）。自我报告的VGDF暴露的风险估计值也高于基于JEMs的VGDF暴露（1.91；1.72 - 2.13 vs 1.10；1.06 - 1.24）。粉尘，尤其是生物性粉尘（1.33；1.17 - 1.51），患COPD的风险估计值最高。尽管大多数职业性COPD研究关注多尘环境，但对于常见形式的职业性空气传播污染物，风险估计值未发现差异。
我们的研究结果强调，由于自我报告的VGDF暴露可能高估了职业性COPD的风险，因此需要谨慎解读先前的研究。
