CANADIAN TASK FORCE ON PREVENTIVE HEALTH CARE

The Canadian Task Force on Preventive Health Care (the Periodic Health Examination) was established in September 1976 under the title the Canadian Task Force on Periodic Health Examination by the Conference of Deputy Ministers of Health of the ten Canadian Provinces. Its stated mandate was: "To determine how the periodic health examination might enhance and protect the health of Canadians and to recommend a plan for a lifetime program of periodic health assessments for all persons living in Canada." Under the founding chairmanship of Dr. Walter O. Spitzer, the membership included epidemiologists, health care researchers, primary caregivers, and specialists. Dr. Spitzer chaired the task force from 1976 to 1984. From 1984 to 1994, the group was chaired by Dr. Richard B. Goldbloom. At the beginning of the twenty-first century the chair was Dr. John Feightner.

Between 1976 and 1978, the task force developed a methodology for evaluating the scientific evidence for and against the effectiveness of any preventive intervention. The characteristic that distinguished the Canadian Task Force methodology from traditional approaches to decision making on preventive issues was that evidence took precedence over consensus. This methodology has become an international standard for evaluating preventive interventions. It included the following hierarchy for evaluating the quality of evidence for effectiveness of any preventive intervention.

QUALITY OF EVIDENCE

• Evidence obtained from at least one properly randomized controlled trial.
• Evidence obtained from well-designed controlled trials without randomization.
• Evidence obtained from well-designed cohort or case control analytic studies, preferably from more than one center or research group.
• Evidence obtained from comparisons between times or places with or without the intervention. Rheumatic results in uncontrolled experiments (such as the results of treatment with penicillin in the 1940s) could also be included in this category.
• Opinions of respected authorities based on clinical experience, descriptive studies, or reports of export committees.

Coupled with the development of the above system for grading the strength of scientific evidence, the task force developed a bidirectional classification of its recommendations, as follows:

1. Good evidence to support the recommendation that the condition be specifically considered in a periodic health examination.
2. Fair evidence to support the recommendation that the condition be specifically considered in a periodic health examination.
3. Poor evidence regarding the inclusion or exclusion of the condition in a periodic health examination but recommendations may be made on other grounds.
4. Fair evidence to support the recommendation that the condition be excluded from consideration in a periodic health examination.
5. Good evidence to support the recommendation that the condition be excluded from consideration in a periodic health examination.

The first task force report, published in 1979, reviewed the scientific evidence for preventability of seventy-eight conditions. This report included a recommendation that the undefined "annual checkup" should be abandoned and replaced by a series of age-specific "health protection packages" that could be implemented in the course of medical visits for other purposes.

The durability of the Canadian Task Force methodology was confirmed in 1984 when the United States Preventive Services Task Force was established. The U.S. group adopted the Canadian methodology essentially unchanged. Subsequently, the Canadian and U.S. task forces worked in close collaboration over many years, each group borrowing freely from the work of the other to avoid unnecessary duplication of effort. As a result, the Canadian Guide to Clinical Preventive Health Care, published in 1994, contains a number of chapters prepared by members of the U.S. Task Force and adapted to the Canadian context. Likewise, the U.S. Guide to Clinical Preventive Services includes a similar number of chapters that originated with the Canadian Task Force.

Since its initial 1979 report, the Canadian Task Force has published forty-four additional reports in the Canadian Medical Association Journal, evaluating the preventability of conditions not considered previously and revising earlier reports in the light of new evidence. Following a hiatus from 1995 to 1997, the Canadian Task Force was reactivated in 1997 and meets regularly. All existing task force reviews have been converted to structured abstract format and posted to the Canadian Medical Association's Clinical Practice Guideline online database (http://www.cma.ca/cpgs/). The task force officially launched its worldwide web site in March 1999 (http://www.ctfphc.org). This web site averaged 3,835 hits per day in 1999. The feasibility of providing consumers versions of task force materials via this web site was being explored. In 1999 the name of the task force was officially changed to Canadian Task Force on Preventive Health Care. The Canadian Task Force continues to maintain a close working liaison with the U.S. Preventive Services Task Force.

Richard B. Goldbloom

(see also Prevention; Preventive Health Behavior )

Web Sites of Interest

Information on the Canadian Task Force on Preventive Health Care is available at http://www.ctfphc.org.