A n occupational health and safety (OHS) management system is designed to protect the health of workers by the following means: designating roles and responsibilities related to OHS; setting organizational targets and objectives related to OHS; planning and establishing the maintenance of hazard controls; and monitoring, reviewing and improving the system's implementation and effectiveness. Federal and provincial legislation (e.g., the Occupational Health and Safety Act in Ontario) specifies simple management systems applicable to all workplaces. Exemplary organizations also seek compliance with voluntary standards and guidelines 1-3 that are more comprehensive. Auditing is a means of directly and comprehensively monitoring the implementation and effectiveness of a firm's OHS management system. 4 The auditing process typically involves the following: 5 gathering evidence about the management system through interviews, documentation reviews and work site observations, guided by an audit instrument; evaluating the gathered evidence; and providing a summary of the evaluative findings. Auditing is an important component of an OHS management system, 1-3 and up to 95% of Fortune 2000 companies perform audits. 6 While less prevalent in smaller firms, audits are recognized as nevertheless relevant. 7 Depending on the type of application in which a particular OHS management audit is involved, researchers and practitioners might want to consider its measurement properties (i.e., reliability, validity, etc.). In some cases, measurement properties are relatively less important. For example, simple audits are sometimes used to assess the management and programmatic needs of organizations that are just starting to develop their OHS management systems. 8 Similarly, there are firms in which management systems are more developed but in which audits are used periodically only to ensure that there are no major gaps in the management system. In these two situations, only a blunt measurement instrument is needed, though one would want some assurance of its content validity: one would want to be confident that the key elements of an OHS management system, appropriate for the organization, are adequately represented in the content of the audit instrument, otherwise it cannot serve its function of identifying gaps. In contrast to the previous examples, additional measurement properties (e.g., interauditor reliability, predictive validity, responsiveness) might also be quite important when audits are used in performance measurement applications. These include benchmarking, determining whether a particular standard has been met or monitoring progress over time. Measurement properties may be additionally important in such applications when the results of audits determine organi
