When conducting a controlled trial is not feasible, observational cohort studies are considered to be the next best option by those in the epidemiological field. To answer questions about OHSMSs, one would follow a large sample of workplaces (the cohort) over time, measuring the introduction or upgrading of OHSMSs and then measuring outcomes of interest at the workplace-level. Sampling workers within those workplaces would allow a more precise estimate of effects on employees. However, such research designs are very expensive and complex to implement, and as such, are used rarely. One example is the Statistics Canada Workplace and Employee Survey, but to date it has been used primarily to answer questions about organizational factors and productivity.
To answer a question about the relative effectiveness of mandatory and voluntary OHSMS initiatives, one would no doubt need to use research designs other than controlled trials, and would likely need to have jurisdiction as the unit of analysis. Such a study would ideally identify and measure other variables at the jurisdiction-level that could bear upon outcomes. Frick et al. (2000, p. 13) indicated what these might be when they listed the contextual factors that are important when establishing an OHSMS strategy (i.e., industrial relations institutions and traditions, labour market arrangements, policies of governance and general production structure). It would be difficult to sufficiently capture all the important variables at the level of country. One alternative might be analyses of jurisdictions that are smaller than countries, so that some of the social and cultural variables will have less variance across the units of analysis. An example of such a study is the one by Smitha et al. (2001), which compared various voluntary OHS initiatives in the United States, using state as the unit of analysis.
There was a dearth of literature on the topic of facilitators/barriers to OHSMSs. If the subject was mentioned at all, the discussion was brief and any related data was not systematically analyzed. Yet, the context in which these systems are implemented and the characteristics of each particular OHSMS may have an important bearing on success or failure. There is a need for more qualitative research that would explore people’s perceptions and experiences of OHSMSs. Such research would enhance understanding of these systems and their contexts. It could identify factors determining the successful implementation and working of OHSMSs.
This review could not address the initial question regarding cost- effectiveness, since no studies contained information on thee cost of an OHSMS intervention. This is an important gap. Clearly decisions about whether to adopt an OHSMS at the workplace- or societal-level would be more informed if research that considered cost-effectiveness was available. In two of the three studies that provided evidence on economic outcomes, the evaluation methods used were primitive.
Effectiveness of Occupational Health & Safety Management Systems: A Systematic Review