Topic 4: Disease surveillance
The scope of this chapter is disease surveillance.
Health surveillance includes the ongoing, systematic collection, analysis and interpretation of data to track disease or exposure over time. Surveillance allows for assessing the magnitude of the disease or exposure, identifying high-risk groups, and targeting prevention efforts. The ongoing collection of data also allows for detecting trends over time. Information gathered during surveillance can inform the design and implementation of prevention strategies for various worker groups and contexts. This review is focused on disease surveillance.
There are different types of information that may contribute to a disease surveillance system:
- population-based administrative databases
- reporting systems and registries
- clinical databases
- case reports/case series
Depending on the type of information used, surveillance in and of itself may not prove causation. It can, however, help identify associations between different exposures and outcomes.
Ontario legislative and regulatory requirements
Ontario has no legislative or regulatory requirements under Occupational Health and Safety legislation.
Consultation and review summary
There are two main sources of surveillance information currently in Ontario that inform occupational disease surveillance.
One is the OCRC Occupational Disease Surveillance System, which uses administrative data from the WSIB and ICES to examine occupational cancers and other occupational diseases.
The other is the patch test databases that inform contact dermatitis and particularly workplace allergens causing disease. Clinicians may also present and publish cases of occupational disease where they have identified new causative agents or agents used in new settings.
A reporting system for occupational asthma was tested in Ontario (see under research). Examples of ongoing reporting systems are those in the United Kingdom (for example Epiderm, SWORD (Surveillance of Work-related and Occupational Respiratory Disease) and THOR (The Health and Occupation Research Network).
Note a comprehensive summary of CREOD research is provided on the CREOD website.
A reporting system for occupational asthma was developed and implemented in Ontario as part of the Asthma Action Plan funded by the Ministry of Health but did not receive ongoing support. A recent study using WSIB researcher and ICES data found that not all individuals with work-related asthma may have an asthma diagnosis in provincial administrative databases.
Patch test databases (both Ontario and North America based) provide current information on exposures in the workplace causing allergic contact dermatitis. The results can be used in a surveillance system to track trends in disease and causative exposures over time and by sector and job.
Reports and reviews
Expert Advisory Panel on OHS (Dean) Report – (2010)
The recommendations provided applied across the system, not just to OD. However, important directions in R#6 and R#7 reference the need to improve data and performance measurement.
Recommendation 6 states “the new prevention organization, in conjunction with the Ministry of Labour and stakeholders, should develop a common database that can be used for planning and evaluation purposes. The system partners, in collaboration with stakeholders, should: develop a common vision of success, and the data needed to determine it, review the occupational health and safety data currently collected, to improve its reliability and validity for the purpose of performance measurement, identify additional information on workers and employers that could be collected and shared, subject to any legislative limitations or restrictions, and review, and where appropriate, consolidate existing leading-indicator initiatives under the new prevention organization.”
Recommendation 7 states “the new prevention organization should establish a business centre to carry out the following functions: standardize, manage and disseminate OHS data, retain and share information on system partner interactions with employers, provide analytical expertise regarding provincial OHS data and manage and authorize stakeholder and public access to data.”
Mining health, safety and prevention review (2015)
This review noted the need for the health and safety system to share information on emerging trends and incidents causing serious injury.
Occupational Disease Advisory Panel – Use of scientific evidence and legal principles in compensation for occupational diseases
This report noted:
- That “Diagnoses can be misclassified or grouped along lines set out by classification schemes that are ill-suited to the purposes of research.” (P15)
- That medical records need only be held for seven years.
Using scientific evidence and principles to help determine the work-relatedness of cancer (Demers)
This report provided recommendations for the development of surveillance systems (pg. ix) and the better exchange of information between MLITSD and WSIB (pg. ix).
Stakeholder focus groups
- There are many challenges with surveillance today, including inconsistent data capture, the relevance of latency data, link with screening missing.
- It is unclear what is being done with reported information — who gathers and how, who analyzes, who decides how to use.
- There is a need for a surveillance system that is independently managed to build trust in the collection and use of data.
- A provincial surveillance organization is required.
- First, they must decide how data should be shared, who has access to the data, and who decides what data needs to be acted upon and how.
- Differences of opinion on where to house the surveillance system.
- Need to bring together MOH, MLITSD, MOE to share data together.
- Look at best practices around the world (for example Finland or Scandinavia).
- What data is included is very important.
- Get clear on the purpose of the surveillance system to know what to collect and how.
- Data is needed for hazard risk assessments and to inform training and prevention priorities.
- It is time to move from lagging indicators to leading indicators.
- Be aware of the limits of epidemiological data.
- Look at actual cases today and what is happening in the workplace, and what exposures exist.
- Work to include occupational and exposure history in health records.
- Need for increased resourcing to build a quality surveillance system.
- To develop quality outputs on trends and to inform priorities.
- To help target proactively going into hazardous workplace settings, including the underground non-union sector, to gather exposure information.
- Need to incentivize employers to participate in surveillance and cluster management.
- Look at the WSIB Excellence Program for ideas on incenting workplaces to participate.
- Identify value add (for example access to healthcare providers or support for cluster investigations).
Summary review findings
- There is agreement on the need for an OD surveillance system in Ontario.
- There is currently no clear accountability for provincial surveillance for occupational disease.
- There are differences of opinion on the purpose of a surveillance system and what data is required.
- There are some components of a possible disease surveillance system already in place (for example Occupational Cancer Research Centre ODSS, patch test databases)
- There is a broader need for and use of data for reporting, recognition and compensation, and the building of a surveillance system needs to identify all the data pieces and get them to usable states so that they work together in a meaningful way.
- Realtime useable data to inform prevention and identify emerging new risks and/or clusters.
- Capacity to detect trends over time and help measure the impact of prevention efforts.
- The system is well understood (purpose/mandate), and data sources and use are trusted.
Short term recommendations
There are many different reasons for surveillance and many different systems possible. Unless there is clarity and agreement about the purpose, methods and outcomes of the system, it will not function effectively, and much investment may be made for little reward. In addition, while our scope is disease surveillance, consideration for exposure surveillance must be part of this process.
4.1 MLITSD lead an OHS stakeholder meeting/process to agree on the purpose of an Ontario disease surveillance system and from where it will operate.
- Consider pros and cons and then prioritize the following intended end uses of the system: Examples of intended use include:
- inform prevention today (for example identify diseases occurring today because of current workplace exposures)
- evaluate effectiveness of previous prevention interventions, including exposure reduction
- inform compensation policy and practice
- Following the decision on purpose above, determine the best operating entity for Ontario based on prior reviews’ recommendations. Options include:
- operating within the MLITSD
- establishing as an independent entity commissioned by the MLITSD
- establishing as an entity independent of the government
- For all options, ensure to leverage linkages with the provincial public health surveillance system and consider other government plans to improve data and performance management across mandates.
Longer term recommendations
4.2 MLITSD commission an expert task force of OHS system data users and experts in disease surveillance methodology to develop the business plan for establishing a disease surveillance system for Ontario.
- Establish an expert task force membership to include OHS system data users/decision makers, experts in clinical and population epidemiology, Ontario Ministry of Health and Public Health Ontario experts with experience in surveillance systems and possible international experts to work through the pros and cons of various possible surveillance systems to provide a recommendation about the type of surveillance required to address the purpose determined in recommendation 1.
- Once the method(s) of surveillance are established, develop:
- operational guiding principles to build trust and resilience (sustainability) from the start
- data needs and sources, including connection to the provincial health information system
- methods for securing, storing and analysing data
- methods/process for providing information to decision-makers and sharing with the public
- organizational plan to execute including a resourcing plan