What can be said about effect of an intervention without a control group? The lack of evaluative evidence is a long-standing problem for regulatory policies against work-related health and safety risks. The European Union Occupational Safety and Health Framework has been in operation for three decades and covers more than 200 million workers, but the most recent evaluation was inconclusive about the benefits generated by this framework. A theory-based evaluation focusing on mechanisms in combination with a design capturing within-intervention variations offers a way forward. The idea is to measure the prevalence of most likely mechanisms and their correlation with outcomes. This approach is illustrated in a large-N evaluation of the use of workplace assessments in the public sector in Denmark. The strengths and weakness of the workplace assessment legislation are assessed. It is shown how findings based on the presented approach contribute to the public debate about workplace assessments.

没有对照组的干预效果如何？缺乏评估证据是针对与工作有关的健康和安全风险的监管政策的长期问题。欧盟职业安全与卫生框架已经运行了三十年，覆盖了2亿多工人，但是最近的评估对于该框架产生的收益尚无定论。基于理论的评估着重于机制，并结合了捕获干预内变化的设计，这提供了前进的道路。这个想法是要衡量最可能的机制的流行及其与结果的相关性。此方法以大号N表示丹麦公共部门对工作场所评估的使用情况评估。评估工作场所评估法规的优缺点。它显示了基于提出的方法的发现如何促进有关工作场所评估的公众辩论。