Volume 19, No.4 - 2000

 [Table of Contents] 

Interest in the surveillance of health-related events is growing rapidly. Surveillance systems in several provinces are undergoing further development, and there are collaborative efforts to enhance surveillance for specific disease groups (such as cancer, cardiovascular disease, diabetes and HIV/AIDS) at the national level. The National Health Surveillance Infostructure (NHSI) is a suite of seven pilot surveillance projects funded by Health Canada and conducted in partnership with stakeholders across Canada.

Developments in surveillance are taking place against a background of greatly increased activity in all aspects of health information, involving all provinces and, at the national level, the Canadian Centre for Health Information (CIHI), Statistics Canada and Health Canada. Interest on the part of the Conference of Deputy Ministers of Health in exploring a more co-ordinated approach to surveillance has led to "A Discussion Paper on an Integrated National Health Surveillance Network for Canada," written by the Federal/Provincial/Territorial Surveillance Integration Design Team. This was released in September 1998 and has been the subject of consultations across Canada.^a

The features that distinguish surveillance from other forms of health investigation are that data are collected routinely, frequently or continuously, and they are generated from the entire population or, less frequently, from a representative sample. The process of surveillance includes not only data collection, but also integration, analysis and interpretation to produce a "surveillance product" for a specific public health purpose or policy objective, as well as the dissemination of that product to those who need to know. Surveillance does not itself constitute investigation, research, risk management or evaluation, although it makes a significant contribution of information that is essential to all of these. Surveillance may, for example, generate hypotheses, which may later be tested by other methods.

The most familiar purpose for surveillance is the identification, as rapidly as possible, of unusual events, outbreaks of disease and emerging health issues. It is worth noting that, although high quality surveillance data are always desirable, for these "early warning" purposes, a balance must be struck between timeliness and high levels of validity.

Another significant role for surveillance is to inform decisions governing the management of risks to health. This may involve public health programs, regulatory action or public policy responses, all of which are exercises in evidence-based decision making, with surveillance being one important source of evidence.

The Discussion Paper recommends several approaches.

• Improved electronic means of accessing currently collected data, together with inventories of existing databases and information on format, quality, security and contact persons

• Integration of information, whether this means taking data from different geographic areas, assembling multiple databases relevant to a health issue or integrating databases at the individual file level

• Using new technology to reduce response times and to facilitate real-time access to data

• Developing and adopting standards-for the classification of diseases, exposures and other health events, database elements, and for informatics

• Developing and sharing innovative electronic means of accessing, integrating, analyzing, presenting and disseminating information

• Developing policies to balance collective interests and the protection of personal privacy

• Strengthening the human resources and skills available across Canada

Partners in the proposed network will include federal and provincial governments, regional and local health authorities, academics, non-governmental organizations (NGOs) and others.

Achieving this vision will require the development of an infostructure, including a means of joint decision making in those areas where the partners have agreed to collaborate; agreements on the ownership, transmission, privacy, security, accessibility and release of data; and funding.

The paper by Choi published in this issue of Chronic Diseases in Canada is intended to stimulate debate on the future of health surveillance. It is instructive to consider the similarities and differences between Choi's vision of surveillance in the 21st century and that of the Design Team. There is agreement on the range of uses for surveillance data, the importance of data quality and the emphasis on making better use of existing data sources. Rather than developing a system from the ground up to provide comprehensive surveillance at the national level, the Design Team proposes to strengthen existing surveillance functions and to build on the current federal, provincial, regional/local and NGO activities. An incremental approach, which facilitates accessibility, sharing and integration of data through a distributed network, standards and metadata, is a practical and realistic means of strengthening surveillance in Canada and moving the surveillance agenda forward.

In an era of increasing interest in evidence-based decision making, the quality and completeness of the information available to decision makers must be improved. As Choi points out, surveillance has a place alongside analytical epidemiology in informing decisions about health. Surveillance contributes speed, frequent or continuous data collection and the ability to ascertain incidence and prevalence in entire populations; analytic studies can provide more information about causation. Both have an important role to play in shaping the decisions that will be taken in future to protect the health of Canadians.

^a For further information, please see the Web site <http://www.hc-sc.gc.ca/hpb/transitn/surveile.html>.

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Author References
David Mowat, Director, Surveillance Transition, Health Protection Branch Transition, Health Canada, Tunney's Pasture, AL: 0701B, Ottawa, Ontario  K1A 0L2