ctfphc&methods

CTFPHC History/Methodology

About CTFPHC
Canadian Task Force Methodology

Brief
Detailed

"Preventive Guidelines: Their Role in Clinical Prevention and Health Promotion" (provides a brief description of primary and secondary clinical prevention as well as some of the issues surrounding care delivery and practice guideline development)

About CTFPHC

Purpose
Key Definitions
History
International Profile
Sponsorship
Membership

Purpose

The purpose of the Canadian Task Force on Preventive Health Care is:

"to determine how the periodic health examination might enhance or protect the health of Canadians and to recommend a plan for a lifetime program of periodic health assessments for persons living in Canada"

Key Definitions

the periodic health examination (PHE): a group of activities, encompassing both primary and secondary prevention, designed either to determine a person's risk of developing disease or to identify early, asymptomatic disease
primary prevention: aims to prevent the occurrence of disease through immunization, by reducing exposure to risk factors or by modifying behaviours
secondary prevention: aims to identify asymptomatic individuals with early stage disease when such early identification promises significantly better response to treatment than in those who first present with symptoms

CTFPHC History

The Canadian Task Force on Preventive Health Care was established in September, 1976 by the Conference of Deputy Ministers of Health of the ten Canadian provinces. The first 2 years were spent developing a methodology for weighing scientific evidence to make recommendations for or against including preventive maneuvers in the PHE of asymptomatic people.

The Task Force recognized then, as it does now, that in clinical practice, caregivers dealing with individual patients must make binary decisions -- "do it" or "don’t do it". It also recognizes, however, that for many preventive interventions, the scientific evidence does not lend itself to such simple two-dimensional alternatives. The particular characteristic that distinguishes the Task Force methodology from traditional approaches to decision-making on prevention issues is that evidence takes precedence over consensus.

The first Task Force report, published in 1979, reviewed the scientific evidence for the preventability of 78 conditions and arrived at an important central recommendation, namely that the undefined "annual check-up" should be abandoned and replaced with a series of age-specific "health protection packages" implemented during the course of medical visits for other purposes.

From 1979 to 1994, the Task Force published 9 updates evaluating the preventability of 19 conditions not considered previously, and revising 28 earlier reports in the light of new evidence. In 1994, we published our landmark compilation of recommendations for 81 conditions, called The Canadian Guide to Clinical Preventive Health Care. This 1009-page volume, affectionately known as "the red brick", has become a standard reference tool for Canadian primary care clinicians.

The Task Force continues to publish its evidence reviews and recommendation, in English and French, in major Canadian journals including the Canadian Medical Association Journal, Canadian Family Physician and Le Médecin du Québec. All CTFPHC reports are also available on this website.

International Profile of the CTFPHC

In the 1980s the Canadian Task Force methodology was adopted, with minimal modification, by the United States Preventive Services Task Force. It has now been applied successfully by the two Task Forces to evaluate the preventability of over 200 conditions and has achieved international recognition as a basis for developing guidelines for clinical practice and public health policy. The Canadian and U.S. Task Forces continue to enjoy a close, constructive collaboration.

Canadian, along with U.S. Preventive Services, Task Force recommendations are currently being used by the U.S. Department of Health and Human Services' "Put Prevention into Practice" initiative to create a resource for clinicians to use when considering preventive care.

In 1995, the French version of the "red brick" won the prestigious Prix Prescrire, awarded annually by the Paris-based journal to a medical/pharmaceutical publication.

Task Force work continues to be cited internationally.

CTF Sponsorship

The Canadian Task Force is funded by Health Canada and is hosted by The University of Western Ontario in London, Ontario.

CTFPHC Membership

Since its inception in 1976, the Task Force has maintained a membership composed of epidemiologists, health care researchers and clinicians, both primary care providers and specialists. Dr. Walter Spitzer chaired the Task Force from 1976 to 1988, and was succeeded by Dr. Richard Goldbloom (1988-1994). Dr. John Feightner has been our Chair since November, 1994. Current members can be found by clicking here.

Canadian Task Force Methodology (click here for detailed version)

CTFPHC Methods
Table 1. Recommendations Grades for Specific Clinical Preventive Actions
Table 2. Levels of Evidence - Research Design Rating
Table 3. Levels of Evidence - Quality (Internal Validity) Rating
Challenges
Decision Making When Evidence is Unclear

CTFPHC Methods

The Task Force strives to provide a bridge between research findings and clinical preventive practice. When research does not provide clear guidance, this lack of evidence is articulated. A major objective is to help physicians choose tests, immunizations, counselling strategies and other preventive interventions of proven utility and avoid those that lack demonstrated value.

We use a standardized methodology, employing explicit analytic criteria, for evaluating the effectiveness of preventive health care interventions. Key features are to:

make recommendations of graded strength, based on the quality of published medical evidence
for a discussion of these recommendation grades, please link to the 2003 article in the Canadian Medical Association Journal here.
place greatest weight on the features of study design and analysis that tend to eliminate or minimize biased results

Table 1, Table 2 and Table 3 provide a summary of the CTFPHC's grades of recommendations, quality of evidence, and analytic criteria.

Table 1. Recommendations Grades for Specific Clinical Preventive Actions

A	The CTF concludes that there is good evidence to recommend the clinical preventive action.
B	The CTF concludes that there is fair evidence to recommend the clinical preventive action.
C	The CTF concludes that the existing evidence is conflicting and does not allow making a recommendation for or against use of the clinical preventive action, however other factors may influence decision-making.
D	The CTF concludes that there is fair evidence to recommend against the clinical preventive action.
E	The CTF concludes that there is good evidence to recommend against the clinical preventive action.
I	The CTF concludes that there is insufficient evidence (in quantity and/or quality) to make a recommendation, however other factors may influence decision-making.
The CTF recognizes that in many cases patient specific factors need to be considered and discussed, such as the value the patient places on the clinical preventive action; its possible positive and negative outcomes; and the context and /or personal circumstances of the patient (medical and other). In certain circumstances where the evidence is complex, conflicting or insufficient, a more detailed discussion may be required.

Table 2. Levels of Evidence - Research Design Rating

I	Evidence from randomized controlled trial(s)
II-1	Evidence from controlled trial(s) without randomization
II-2	Evidence from cohort or case-control analytic studies, preferably from more than one centre or research group
II-3	Evidence from comparisons between times or places with or without the intervention; dramatic results in uncontrolled experiments could be included here
III	Opinions of respected authorities, based on clinical experience; descriptive studies or reports of expert committees

Table 3. Levels of Evidence - Quality (Internal Validity) Rating (see Harris et al., 2001)

Good	A study (including meta-analyses or systematic reviews) that meets all design-specific criteria* well.
Fair	A study (including meta-analyses or systematic reviews) that does not meet (or it is not clear that it meets) at least one design-specific criterion* but has no known "fatal flaw".
Poor	A study (including meta-analyses or systematic reviews) that has at least one design-specific* "fatal flaw", or an accumulation of lesser flaws to the extent that the results of the study are not deemed able to inform recommendations.
*General design-specific criteria are outlined in Harris et al., 2001.

Some Challenges for Evidence-based Prevention

The CTFPHC has identified that a number of important issues arise during and following the development of clinical preventive guidelines:

there are a relatively large number of "C" and "I" Recommendations (due to insufficient, inconclusive, or conflicting evidence), leaving clinicians to make decisions on other grounds -- this may be frustrating
we need to consider all varieties of benefit and harm associated with any preventive maneuver, including improved quality or length of life, anxiety relieved or money saved, cost, "labelling" and anxiety, including that induced by earlier diagnosis
a "C" or "I" Recommendation can serve as a caution to those who have to decide which preventive measures justify public funding
many preventive interventions that have the potential to improve health lie outside the context of the clinician-patient encounter - the prevention of poverty, of violence and of pollution are striking examples
while cost of care is an inescapable and serious consideration, economic analysis of clinical preventive actions is complex and not yet fully developed. It is not yet a major focus of Task Force evaluations
choices may have to be made, on both monetary and ethical grounds, between preventive interventions for unrelated conditions

Decision Making When Evidence is Unclear ("C" Recommendations)

Guiding Factors for Decision-Making:

increase patient involvement in decision-making
minimize harm
advocate major change only on strong proof of need
avoid unnecessary labelling
avoid expensive manoeuvres of unclear benefit
focus on conditions with a high burden of illness
be attentive to special needs of high risk groups

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