Evidence, not ideology, must guide preventive health care policy recommendations

Key points

• The Canadian Task Force on Preventive Health Care has historically led the way globally in the development of evidence-based guidelines.

• Concerns were raised in recent years about the work of the task force amid perceptions that its methods may be too rigid.

• A recent review of the task force found that such work is more necessary than ever, but approaches do need to be modernized.

• Any new iteration of the task force needs sustainable governance and funding, updated methodologies, and an inclusive and transparent approach.

United States Secretary of Health Robert F. Kennedy Jr. recently dismissed all members of the Advisory Committee on Immunization Practices, a respected body of technical experts whose recommendations shape vaccination guidelines used by physicians across the US.¹ The secretary stated that this was done to restore public trust and ensure that “unbiased science guides” recommendations. However, as replacements, he appointed individuals with limited immunization expertise, some of whom are known for vaccine skepticism.²

Canada has taken a different path in response to concerns raised about a guideline committee: an expert panel was convened in response to criticism of the Canadian Task Force on Preventive Health Care and the evolving demands on its mandate.³ I had the privilege of chairing the panel. Minister of Health Marjorie Michel released the panel’s report, Modernizing Preventive Health Care Guideline Development in Canada: A Way Forward, in June 2025.⁴

The US and Canada offer a study in contrasting responses to a broader, global erosion of trust in science and expertise — particularly when it comes to public health. Breakdown of public trust in science has been evident for some time, but the COVID-19 pandemic greatly accelerated it, and a rise in the public’s use of social media has magnified it further by allowing the unchecked spread of misinformation and disinformation.⁵ Whereas the US has chosen to politicize and destabilize its evidence-based advisory process, Canada has chosen to modernize it.

The review panel I chaired worked over several months to review previous evaluation reports, assess best practices globally, and consult broadly. Our review affirmed that we need expert bodies like the task force, now more than ever, to produce evidence-based guidance for the public, health care practitioners, and health systems.

Canada led the way in 1976 with establishment of the Canadian Task Force on the Periodic Health Examination (as it was then known).⁶ The group pioneered methodology for evaluating and grading scientific evidence to make recommendations for preventive services in healthy people. CMAJ provided space for the publication of the guidelines, an important support for their dissemination in the pre-Internet era. The initial report of the task force reviewed the prevention of 78 conditions and debunked the notion that healthy adults needed an annual physical, recommending instead age-specific preventive interventions.⁷

At the time, decisions in medicine were largely based on “expert” opinion. Those with stature, influence, and authority could drive care and policy in entire populations, with the potential to lead to substantial harm.

The task force pioneered the now-standard methods of evaluating clinical interventions not by tradition or authority but according to rigorous scientific evidence. The evidence-based medicine movement, whose development was led by clinicians at McMaster University, transformed preventive medicine globally and is among the most important achievements in health care worldwide.⁸

The task force has reinvented itself before. Twenty-five years ago it faced being shut down, drawing international attention,⁹ as well as an obituary in these pages.¹⁰ Fortunately, funding was restored a few years later and the group was reconstituted, but without the direct connection to the Conference of Deputy Ministers of Health that the original task force had.¹¹ This resulted in the Canadian Task Force on Preventive Health Care, as it was renamed, having a weaker relationship to provincial and territorial health systems which, at that time, were developing their organized cancer screening programs. Funding flowed through the Public Health Agency of Canada to a host university for administration purposes. Subgrants were provided to evidence synthesis centres and a group to support knowledge translation. But most of the work was done by volunteer health professionals.

In recent years, the task force repeatedly came under criticism, particularly with respect to guidelines for mammography screening.³ It has been criticized as slow, heavily reliant on evidence from randomized controlled trials, rigid in implementing conflict-of-interest rules to the exclusion of those with expertise in certain areas, and lacking in transparency and accountability.

Although the review committee I chaired found that there was some basis for such concerns, fundamentally, a broader set of considerations point to a need to modernize the task force. We recommended that the mandate and role of the task force be updated to reflect the changing nature of preventive practices, the expanding engagement of patients in shared decision-making (coupled with increasingly diverse sources of information and misinformation), the changing modes of provision of primary care (including the many Canadians without access to primary care at all), and the growing complexity of organized prevention programs in many jurisdictions.⁴

Methods for summarizing and updating evidence are evolving rapidly, particularly with new technology. New tools can help update and disseminate guidelines more quickly. And national coordination can reduce duplication and confusion. Importantly, ensuring that guidelines meet the needs of the entire Canadian population is critical. A strict evidence-based approach that relies on studies restricted to certain populations means that the guidelines may not be relevant for all populations or settings. An equity and inclusion lens must be applied in developing and implementing guidelines.⁴

Transparency and governance are critical. Processes for appointing members are necessary, as are strong processes to address conflict of interest, while ensuring the voices of those with relevant expertise are heard. It is essential that the work of the task force is protected from undue interference from external bodies, including governments.¹²

Any new iteration of the task force must be funded, supported, and governed to meet the urgency and scale of its work. For decades, this important body has delivered high-impact work on a shoestring budget, relying on the time and expertise of many volunteers.⁴

How Robert F. Kennedy Jr.’s replacements on the Advisory Committee on Immunization Practices will build confidence in the recommendations of that body, which is what the secretary appears to have intended, will be an interesting experiment to watch. However, Canada has the opportunity to reclaim global leadership in preventive health. A modernized Canadian body that makes national preventive care recommendations will not just improve care — it will be a statement of Canadian values. As others retreat from science, Canada can lead with integrity, inclusiveness, and evidence, with a strong, independent body that is well resourced to produce high-quality guidance.