The CTFPHC Newsletter Issue 8

The CTFPHC Newsletter Issue 8

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The Canadian Task Force on Preventive Health Care (CTFPHC) is composed of experts who develop recommendations for clinical preventive services delivered by Canadian primary care practitioners. The CTFPHC is responsible for prioritizing the topics that will be reviewed and works with the Prevention Guidelines Division of the Public Health Agency of Canada to define the analytic framework and scope of each topic. In the preparation of evidence reviews and the development of recommendations for each topic, the CTFPHC collaborates with two evidence review and synthesis centres and the Prevention Guidelines Division. The CTFPHC also leads knowledge translation (KT) and dissemination activities to promote guideline reach and uptake.


Message From the Chair

Greetings! In this issue, I am pleased to announce the release of our newest clinical practice guideline. In February 2016, the CMAJ published the CTFPHC’s Recommendations on Screening for Colorectal Cancer in Primary Care. For more information about the colorectal cancer guideline, systematic review, and associated KT tools, please visit the CTFPHC colorectal cancer guideline page.

I am also happy to share a piece written by former CTFPHC member Dr. Neil Bell on interpreting the CTFPHC’s 1000-people tools.

As always, we appreciate your interest in the CTFPHC and we encourage you to stay up to date on our work by visiting our website at

Marcello Tonelli, MD SM


Release of the CTFPHC’s Colorectal Cancer Screening Guideline

The CMAJ published the CTFPHC’s tenth guideline in February

  1. This latest guideline addresses screening for colorectal cancer (CRC) in adults aged 50–74 years old.

CRC is the second-most common cause of cancer mortality in men and the third-most common cause in women. Although the burden of CRC varies across Canada, it is estimated that 25,000 Canadians were diagnosed with CRC in 2015 and 9,300 died from the disease. The incidence and mortality of CRC are low until middle age and increase rapidly thereafter.

The CTFPHC’s CRC guideline presents recommendations for screening for CRC in adults 50 years and over who are not at high risk for CRC. The recommendations do not apply to those with previous CRC or polyps, inflammatory bowel disease, signs or symptoms of CRC, hereditary syndromes predisposing them to CRC or a family history of CRC.

Evidence shows that screening for CRC with gFOBT or flexible sigmoidoscopy reduces the incidence of late-stage CRC and CRC mortality. Because FIT has a greater sensitivity than gFOBT and similar specificity, the reported mortality benefits of gFOBT for people aged 50-74 years can be extended to FIT. Given that these benefits outweigh the harms of screening with FOBT or flexible sigmoidoscopy, the CTFPHC recommends screening for CRC with gFOBT or FIT every two years or flexible sigmoidoscopy every 10 years in adults aged 50-74.

Because the incidence of CRC is higher in adults aged 60-74 years than in adults aged 50-59 years, the recommendation to screen individuals aged 60-74 years is a strong recommendation whereas the recommendation to screen individuals aged 50-59 is a weak recommendation. The strong recommendation to screen individuals aged 60-74 years with gFOBT, FIT, or flexible sigmoidoscopy indicates that primary care practitioners should offer the service to all individuals in this age group. The weak recommendation to screen individuals aged 50-59 years with gFOBT, FIT, or flexible sigmoidoscopy indicates that a more nuanced discussion about harms and benefits will be required in this population.

The recommended age to stop screening is 75 years based on reduced life expectancy in older age groups and the lack of evidence that screening reduces mortality in this age group. However, adults over 74 years of age who are healthy (with longer life expectancy) and are less concerned with the lack of reported benefit or the potential harms of screening may prefer to be screened. For this reason, the CTFPHC has made a weak recommendation to not screen patients over the age of 74 for CRC.

Although screening with colonoscopy may provide some clinical benefits, there is limited evidence of its efficacy compared to other screening tests. In addition, waiting lists for colonoscopy in Canada have increased over time and this test requires greater resources than other screening tests do. As a result, the CTFPHC has made a weak recommendation against using colonoscopy as a primary screening test for CRC.

We encourage primary care providers to discuss the most appropriate choice of test with patients of any age group who are interested in screening.



To accompany its screening for CRC guideline, the CTFPHC developed a patient FAQ sheet and a recommendation table for clinicians. The FAQ sheet provides answers to common questions that patients may have about screening for CRC. The recommendation table provides guidance for primary care practitioners on different screening tests, screening intervals, and recommended ages to start and stop screening. Copies of the patient FAQ and the clinician recommendation table are available to download for free on the CRC guideline page on the CTFPHC website. As always, the CTFPHC encourages members of the public to discuss screening for CRC with their primary care practitioner, who is aware of their health background and family history.


The 1000-Person Knowledge Translation Tool – An Increasingly Popular Way to Understand CTFPHC Screening Recommendations

Neil Bell, MD

An important role of the CTFPHC is to develop effective KT strategies that make the guideline recommendations more accessible and understandable to potential users. Part of the CTFPHC’s KT strategy for each guideline includes developing KT tools that provide patients and clinicians with a better understanding of the potential benefits and harms associated with the preventive screening recommendations in the CTFPHC guidelines.

Some of the most popular and rapidly adopted KT tools developed by the CTFPHC are the 1000-person diagrams, which visually illustrate and explain the key benefits and harms associated with a particular preventive health care screening strategy. The tools consist of an infographic of 1000 people that highlights the relative proportion of people (i.e., the number out of 1000) who will experience various outcomes after getting screened. Common outcomes that may be highlighted in this tool include the proportion of individuals who would screen positive with a test, the proportion who would test true positive or false positive, the proportion who would be diagnosed with a condition or disease, and estimates of the proportion of people who would benefit from the screening test compared to those not screened. The tool also often illustrates the number of people who would be overdiagnosed. Overdiagnosis is the diagnosis of disease that would not cause the patient any harm and for which treatment would not provide any benefit. In addition, the tool includes information about the harms associated with follow-up testing that is needed to confirm a diagnosis and the harms associated with any treatment strategies. To date, the CTFPHC has developed 1000-people tools for its guidelines on prostate cancer screening and its recent lung cancer screening guideline. The CTFPHC also developed a similar tool for its breast cancer screening guideline.

In addition to the infographic, the 1000-people KT tools include information about the patient population to which the guidelines apply and a description of the intervention and screening strategies. The tools may also include information about alternative diagnostic approaches for the disease or condition covered by the guideline. Furthermore, they reference the evidence source on which the information contained in the tool is based.

Clinicians have found that the 1000-people tools are useful for supporting evidence-based discussions with patients during office visits. The tools can be provided to patients to either review in the office or take home for further consideration. The tools can also provide a quick update to clinicians on the key harms and benefits associated with a screening strategy, be included in electronic medical records, and assist in medical education.

The 1000-people tools are developed in conjunction with the guideline recommendation by members of the CTFPHC guideline working group, CTFPHC scientific staff, and the staff from the Knowledge Translation Program in the Li Ka Shing Knowledge Institute at St Michael’s Hospital in Toronto. They are published with CTFPHC guidelines where appropriate and can be downloaded from the CTFPHC website in either colour or black and white. Additional information on the 1000-person tools can be obtained from the CTFPHC.


GRADE: Question and Answer

The CTFPHC develops its guidelines using the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) method. This is an internationally recognized method for evaluating systematic review evidence to develop clinical practice guidelines. In each issue of the CTFPHC newsletter, we will discuss one frequently asked question regarding the use of GRADE.

Question: Why does the CTFPHC use GRADE?

Answer: The CTFPHC uses GRADE because it is a systematic approach that overcomes the shortcomings of other grading systems and provides a common language for guideline developers to use when describing recommendations. The GRADE system offers guideline developers a transparent, systematic approach to reviewing research evidence in health care and to developing guideline recommendations for policy and practice. It provides a framework for explicitly considering the quality of evidence, trade-offs between the harms and benefits, the values and preferences of patients, and the net balance of cost and health benefits.


Opportunities for Engagement

Patient Engagement in Guideline Development
The CTFPHC now engages patients in its guideline development process. Specifically, the CTFPHC recruits patients to provide input at up to two stages of the process: (1) when outcomes are selected for inclusion in the systematic review protocol that informs the guideline and (2) when the guideline recommendations are developed. The CTFPHC uses feedback provided by patients to guide the search for evidence on the harms and benefits of preventive health care interventions and to develop KT tools to accompany the guidelines.

The CTFPHC recently engaged patients in Stage 2 for its guideline on tobacco smoking prevention and cessation in children and youth. We will soon be engaging patients in Stage 2 for the CTFPHC’s guideline on screening for hepatitis C.

Usability Testing of Practitioner and Patient Tools
The CTFPHC produces practitioner and patient tools to support each of its guidelines. To ensure that the content, layout, navigation, and aesthetics of these tools are appropriate and useful for practice, we conduct usability testing with practitioners. If you are interested in reviewing and providing feedback on one of our upcoming guideline tools, please email Kavitha Thiyagarajah, research assistant, at for more information. Note that we offer $100 compensation for a one-hour telephone interview.


Guidelines in Progress

  • Screening for developmental delay
  • Screening for hepatitis C
  • Screening for abdominal aortic aneurysm
  • Tobacco smoking prevention and cessation in children and adolescents


Topic Suggestions

Is there a preventive health topic that you would like to see the CTFPHC develop a clinical practice guideline for? Let us know what you are passionate about! We accept topic suggestions on a rolling basis and would love to hear from you. To submit a suggestion, please email us at with the subject line “Topic Suggestions”.


Suggestions for the next newsletter

Is there a subject that you would like to see addressed in the next issue of the CTFPHC newsletter? Let us know what you’d like to see covered! We accept suggestions on a rolling basis. To submit a suggestion, please email Kavitha Thiyagarajah, research assistant, at with the subject line “Newsletter Suggestions”.