International Review of Surveillance and Control of Workplace Exposures: NOHSAC Technical Report 5
5. Implications For Practice and Implementation
The formal literature review and the survey work found a large number of surveillance systems, addressing a broad cross-section of hazards and disease outcomes. The use of more than one monitoring system per country seems to be common to gather the information that enables the construction of work and health country profile reports. These systems are variously categorised and defined. In an attempt to simplify the definition of system types and identification of specific systems and to address some apparent confusion in regard to the term “exposure surveillance”, it is suggested that the terms “worker health surveillance” and “work environment surveillance” are used to distinguish between disease and outcome-focused systems and exposure-focused systems respectively.
The greatest amount of work in regard to surveillance system definition, analysis and development has been undertaken in Europe, and work by Rantanen et al, Smulders and the European Foundation for the Improvement of Living and Working Conditions offers a significant resource on which to draw during analysis and development of work environment surveillance in New Zealand and Australia.
From the literature, four categories of work environment surveillance system have been proposed, these being i) integrated systems, ii) working conditions surveys, iii) workplace observations and OHS services data and iv) registers. Each of these categories has been defined in section 3.6, and the systems within each category have application in different contexts and thus have relative merits. Characteristics of successful systems are detailed in section 2.4.1.
Of the systems that fall within the four categories defined, the fullest review possible has been undertaken, given the information available and constraints imposed by the project timeframes. It is difficult to obtain a sense of and subsequently describe the subtleties and nuances of the systems reviewed without spending time immersed in the respective systems. Similarly, it is difficult to assess the adaptability or suitability of one or more types of system to the Australian and New Zealand contexts, without experiencing the operation of the total socioeconomic, legislative and political structures and the interaction of their associated key elements in the originating country. Therefore, a birds-eye view rather than a three-dimensional view of the elements could be presented.
In addition, the review and evaluation of the systems has been retrospective and, in many cases, some years after the implementation of the systems in their countries of origin. The review reflects the current state of operation, therefore the nuances associated with establishment and commissioning of the systems, information which would be highly valuable for Australia and New Zealand in adopting and adapting systems, may have been lost over time, particularly where the people originally involved have moved on.
Exposure databases, such as the German MEGA, the Finnish FINJEM, the Singaporean Noise and Chemicals Exposure and British NEDB systems, which feature as one element in an integrated approach, are obviously attractive, as observational surveys, containing many quantitative measurements of exposure collected by agency hygienists, external surveyors or a combination of these. The databases represent a significant resource on which to draw for the purposes of policy setting, exposure standard setting, trend monitoring and evaluation of interventions. They do, however, require a commitment of significant resources to access workplaces and collect data in sufficient volumes across a sufficiently broad population to be of value. On-going maintenance of the database similarly requires significant resources. Success is heavily dependent upon the long-term commitment to availability of resources and industrial and socio-political structures that support the approach. The extent to which the system is embedded in and coincident with other data collection systems in the country of operation influences their success.
Interview surveys and other questionnaire-based surveys on working conditions are increasingly carried out in many countries and featured significantly in the review of the 24 surveillance systems. They provide valuable information on the prevalence of perceived exposure to some physical agents, ergonomic factors, physiological factors, psychosocial factors, life-style factors, on work ability, and on the occurrence of work-related symptoms. They appear to offer flexibility in terms of the hazards they address, the target population and the periodicity of application. While they demand less on-going commitment of resources, they collect qualitative data rather than quantitative and thus have less validity and reliability. The range of hazards about which exposure data may be gathered is limited, for example, collection of data regarding exposure to carcinogens is unlikely to be successful.
Workforce surveys are, however, attracting increasing interest in Europe, and indeed, the European Foundation for the Improvement of Living and Working Conditions is positively promoting the approach within that region. Emerging from discussions during the survey component of this project is an initiative in Europe to establish a Risk Observatory, which will undertake a major review of workforce and company surveys completed in Europe every five years, and bring together a picture of the current situation in regard to exposures and identify trends and emerging risks. It will attempt to link these findings to worker health surveillance data, physical environment, ergonomics and design data and, especially, work and work organisation data. It is anticipated that 3–4 reports will be generated annually. Funds of approximately 500,000 Euros have been committed to establish the Risk Observatory, which launched its internet site at the end of 2005. Six people are allocated to the operation of the programme with funding increasing once the programme is launched.
Registers offer an approach that yield higher reliability and validity than surveys where national data are comprehensive, and they may provide a solution to the problem created where other data sources are unreliable. However, they are dependent on the availability of financial resources and experts who can provide subjective input.
The review of the 24 work environment surveillance systems found them at various stages of development and levels of activity. All had been initiated by some trigger such as legislation or identification of a priority hazard requiring attention. Significantly, a number were stimulated by recognition of the effects of the rapidly changing nature of work and the need to establish an evidence base in regard to exposures. While not explicit in the drivers for the establishment of most systems, hazard control was cited as an aim by a number of systems. However, given the role of exposure assessment as a means to an end rather than an end in itself, it was somewhat surprising that influencing hazard control did not feature more significantly as an overarching aim.
The systems reviewed predominantly focused on larger target populations, this being influenced to some degree by the processes for short-listing the 24 systems as described. However, a range of parameters such as occupation, industry or hazard are used to target specific populations. What parameters are used depends on the aim of the system. While workforce surveys appear to offer the greatest flexibility and can encompass wide ranges of occupations, industries and hazards, they are not appropriate for all contexts or hazards, given that, in some cases, the hazard may not be recognisable by respondents.
While it would appear that the intended users of the systems are diverse, there did not appear to be any strategy for targeting specific user groups at system inception. Potential users of systems include policy-makers, OHS professionals, epidemiologists, researchers, lawyers, trade unions and journalists. Individual companies may benefit from systems that capture company-specific data, these largely being workplace observation-based systems. However, industry sectors can derive benefit from information that is either captured and/or sorted to facilitate access to relevant datasets. Information is made available to users by reports and via datasets, generally via the internet. Ethical issues do not seem to arise in general as a result of available data being anonymous. The currency of datasets varies according the availability of resources to support regular additions of data and its maintenance.
While a number of systems cite transferability of data and the facilitation of comparisons between countries in the aims, this has not generally been successful as a result of differences in definitions, industries and social structures.
Regardless of the type of surveillance system in operation, the enablers and barriers seem to be common. Factors cited as enablers included legislative and socio-political frameworks that support or even require data collection. Structures within OHS agencies that support robust teams that can collect data or at least review samples of data are similarly significant. A high degree of usage lends weight to the justification of resources allocation, and enthusiastic individual advocates are significant. Barriers that were cited were generally in regard to the availability of resources as well as an inability to demonstrate the impact of a system.
Based on these findings and their interpretation, supported by anecdotal information collected during conversations and other exchanges with informants, Table 20 is an attempt to overlay the categories of systems identified over the matrix of OASCC and NOHSAC hazard categories, surveillance methods and priority diseases and injuries.
The table suggests what may be the best approach for the surveillance of exposures in relation to priority outcomes reviewed within literature and through survey work. The best system in each case is suggested as the system that is potentially most effective for work environment surveillance data to be collected about the hazard categories and injury or disease outcomes in question. These types of systems may or may not be the most applicable systems for the Australian and New Zealand environments.
Also presented is an indication of what may potentially be the most applicable system for the surveillance of exposures in relation to priority outcomes in Australia and New Zealand. The indication of the most applicable system has been derived through consideration of the best system and other good systems, and viewing each of those through broad social, political, economic and legislative lenses associated with both the country of origin and Australian and New Zealand situations.
It has been suggested earlier in the report, based on the Smulders study, that the use of more than one monitoring system seems to be needed to gather the information necessary for work and health country profiles. It is clear, then, that the best system for any country to adopt is an integrated system, which provides a means of combining various methods for surveillance of both the work environment and worker health into one system. Links within this system permit timely identification of opportunities for risk control that can track through monitoring of the outcome data for the country. This system is a complex and highly resource-intensive method of surveillance, and the difficulties of implementing such a system appear to be evidenced through the limited number of systems of this type identified around the world.
The other best alternative for work environment surveillance appears to be a system based on workplace observations, particularly for the reasons described by Boiano & Hull and Rantanen et al, i.e. the reproducibility of quantifiable results, the systematic nature of the methodology based on representative samples and the reliability associated with experts visiting workplaces and objectively assessing the situation. However, these systems are also limited by the features inherent in such an approach, that is, the slow and expensive nature of data collection and analysis, access to workplaces and the need for uniform coding of data. The use of these databases is further limited by a lack of consensus regarding core information, accurate and standardised definitions for core information and effective coding.
The success of the systems within the countries in which the best systems originate is heavily dependent on cultural, legal and industrial structures, which enhance their operation. Australia and New Zealand are quite different to these countries of origin; politically, legally and in terms of industrial structures. In addition, these two countries have smaller, geographically more widespread populations with fewer resources. Both countries are experiencing changes to the labour market resulting in increasing numbers of smaller businesses that stretch the ability of experts and regulators to conduct comprehensive workplace visits.
The table below, contrasting the best as well as potentially the most applicable systems, is presented for consideration and to stimulate further discussion.
In regard to chemical hazards leading to respiratory disease, it would appear that integrated systems and registers would offer the most comprehensive resource. With the continued growth of respiratory disease health surveillance systems in the UK and development of similar outcomes-based indicator systems in New Zealand and Australia, integrated systems are particularly attractive. However, the resource demands of such systems and the relatively small population base may be limiting, and thus it is suggested that questionnaire-based approaches, using instruments already developed in Europe, may be appropriate.
Conversely, in regard to occupational carcinogens, questionnaire-based approaches are unlikely to be successful, given the likely failure of respondents to recognise such hazards. Thus for carcinogens, registers are likely to be the most useful and appropriate systems.
The Nordic Skin Questionnaire and the inclusion of skin hazards exposure-related questions in European workforce surveys suggest that a similar approach may be both preferred and potentially most applicable in New Zealand and Australia.
In regard to noise exposure and musculoskeletal disorders, workplace observations for the purposes of quantitative assessment are attractive. However, given the resource demands and the potential for assessment of these hazards by qualitative indicators that may be included in questionnaires, this approach is suggested as potentially most appropriate.
In regard to biological hazards, the most appropriate approach is particularly heavily influenced by the nature of the biological agent and the route of transmission (for example, comparing legionella pneumophila infection via air conditioning systems versus HIV transmission via needlestick). However, once again, the nature of the more common exposures and the constraints imposed by resources and population sizes suggests that questionnaire-based systems may potentially be appropriate.
The success elsewhere of questionnaire-based surveys for assessment of psychosocial risk similarly lends weight to the suggestion that questionnaire-based surveys may be appropriate in regard to assessment of exposures.