Glazner J E, Borgerding J, Bondy J, Lowery J T, Lezotte D C, Kreiss K
Department of Preventive Medicine and Biometrics, University of Colorado School of Medicine, Denver, USA.
Am J Ind Med. 1999 Feb;35(2):175-85. doi: 10.1002/(sici)1097-0274(199902)35:2<175::aid-ajim9>3.0.co;2-p.
We sought to explain the variation in injury rates found for categories of companies and contracts involved in the construction of the Denver International Airport (DIA) by surveying contractors about company and contract-level safety practices.
We conducted 213 telephone interviews (83% response) with representatives of contracts with payrolls of more than $250,000. We investigated the bivariate relationship between safety actions reported in the survey and injury occurrence by calculating the aggregate injury rates (lost work-time (LWT) rates and non-LWT rates) for the group of respondent contracts reporting always taking the action and for the group not always taking the action. Using Poisson regression, we examined the association between contract injury rates and contract safety practices while controlling for variables previously shown to affect contract-level injury rates.
In Poisson regression, two actions, 1) disciplinary action always resulting when safety rules were violated and 2) always considering experience modification ratings when selecting subcontractors, were associated with lower LWT injury rates. Three actions or contract characteristics resulted in lower non-LWT rates: management always establishing goals for safety for supervisors, conducting drug testing at times other than badging or after an accident, and completing the DIA contract on budget, rather than over budget. Reportedly consistent use of a number of accepted safety practices was associated with significantly higher injury rates in bivariate and multivariate analyses.
The pattern of counterintuitive results found in this study suggests that questions reflecting agreed-upon safety practices, when asked of the person responsible for all on-site construction activities, are likely to elicit normative responses. Objective validation of reported safety practices is critical to evaluating their efficacy in reducing injury rates, along with measures of both time at risk and outcome and control for prevailing risk of the work performed.
我们试图通过就公司和合同层面的安全实践对承包商进行调查，来解释在丹佛国际机场（DIA）建设中涉及的公司类别和合同的受伤率差异。
我们对工资总额超过25万美元的合同代表进行了213次电话访谈（回复率83%）。我们通过计算报告总是采取该行动的受访合同组和不总是采取该行动的合同组的总受伤率（误工时间（LWT）率和非LWT率），研究了调查中报告的安全行动与受伤发生之间的双变量关系。使用泊松回归，我们在控制先前显示会影响合同层面受伤率的变量的同时，研究了合同受伤率与合同安全实践之间的关联。
在泊松回归中，有两项行动，1）每当违反安全规则时总是采取纪律处分，以及2）在选择分包商时总是考虑经验修正率，与较低的LWT受伤率相关。有三项行动或合同特征导致较低的非LWT率：管理层总是为监管人员设定安全目标，在除徽章佩戴时或事故后之外的其他时间进行药物检测，以及按预算而非超预算完成DIA合同。在双变量和多变量分析中，据报道一些公认的安全实践的持续使用与显著更高的受伤率相关。
本研究中发现的违反直觉的结果模式表明，当向负责所有现场施工活动的人员询问反映公认安全实践的问题时，可能会引发规范性回答。对报告的安全实践进行客观验证对于评估其在降低受伤率方面的功效至关重要，同时还需要对危险时间和结果进行测量，并控制所执行工作的主要风险。
