Canadian Preventative Screening Guidelines

Abdominal Aortic Aneurysm (AAA)

• 2017 CTFPHC Guideline:
• The CTFPHC recommends one-time screening with ultrasound for abdominal aortic aneurysm for men aged 65 to 80. (Weak recommendation; moderate quality of evidence).

• 2019 USPSTF Guideline:
• The USPSTF recommends one-time screening for abdominal aortic aneurysm (AAA) by ultrasonography in men aged 65 to 75 who have ever smoked.
• NNS = 625, 3 will need surgery (5.5% mortality from surgery)

Alcohol Use

• 2018 USPSTF Guideline:
• We recommend screening for unhealthy alcohol use in primary care settings in adults 18 years or older, including pregnant women, and providing persons engaged in risky or hazardous drinking with brief behavioral counseling interventions to reduce unhealthy alcohol use. (B recommendation).

Breast Cancer

• 2018 CTFPHC Guideline:
• For women aged 40-49 years, we recommend not screening with mammography; the decision to undergo screening is conditional on the relative value a woman places on possible benefits and harms from screening. (Conditional recommendation; low-certainty evidence).
• For women aged 50-74 years, we recommend screening with mammography every two to three years; the decision to undergo screening is conditional on the relative value that a woman places on possible benefits and harms from screening. (Conditional recommendation; very low-certainty evidence).
• We recommend not using magnetic resonance imaging (MRI), tomosynthesis or ultrasound to screen for breast cancer in women not at increased risk. (Strong recommendation; no evidence)
• We recommend not performing clinical breast examinations to screen for breast cancer. (Conditional recommendation; no evidence)
• We recommend not advising women to practice breast self-examination to screen for breast cancer. (Conditional recommendation; low-certainty evidence)

Cervical Cancer

• 2013 CTFPHC Guideline:
• For women aged 25 to 69 we recommend routine screening for cervical cancer every 3 years.
• For women aged ≥70 who have been adequately screened (i.e. 3 successive negative Pap tests in the last 10 years), we recommend that routine screening may cease. For women aged 70 or over who have not been adequately screened we recommend continued screening until 3 negative test results have been obtained.

• 2018 USPSTF Guideline:
• The USPSTF recommends screening for cervical cancer every 3 years with cervical cytology alone in women aged 21 to 29 years. (A recommendation)
• The USPSTF recommends screening every 3 years with cervical cytology alone, every 5 years with hrHPV testing alone, or every 5 years with hrHPV testing in combination with cytology (cotesting) in women aged 30 to 65 years. (A recommendation)
• The USPSTF recommends against screening for cervical cancer in women younger than 21 years. (D recommendation)
• The USPSTF recommends against screening for cervical cancer in women older than 65 years who have had adequate prior screening and are not otherwise at high risk for cervical cancer. (D recommendation)
• The USPSTF recommends against screening for cervical cancer in women who have had a hysterectomy with removal of the cervix and do not have a history of a high-grade precancerous lesion or cervical cancer. (D recommendation)

• 2012 Saskatchewan Guideline:
• Screening should start at age 21 or 3 years after first sexual activity, whichever occurs later.
• Screen every 2 years until 3 consequtive normal results, then extend screening to every 3 years.
• Continue annual screening for women at risk:
  • ever had a biopsy confirmed high‐grade squamous intraepithelial lesion (HSIL) or adenocarcinoma in situ (AIS)
  • immunosuppressed and have ever been sexually active

• NNS = 1000 over 35 years to prevent one cervical cancer death (150 abnormal results, 80 referred for investigation, 50 have treatment)

Colon Cancer

• 2016 CTFPHC Guideline:
• We recommend screening adults aged 50 to 74 with FOBT (either gFOBT or FIT) every two years or flexible sigmoidoscopy every 10 years.
• We recommend not screening adults aged 75 years and over.
• We recommend not using colonoscopy as a screening test.
• Considerations:
  • No difference between annual or biennial FOB screening (Cochrane Review, 2008)
  • Colonoscopy has increased sensitivity, but at what cost (i.e. resource allocation)?
  • What does a FIT result say about my chances of having colon cancer? PPV = 6.8%, NPV = 99.9% (CMAJ 2011, Sept 20)
  • Colon cancer generally takes 10 years to develop: if less than 10 years' life expectancy, discuss with patient but likely don't screen.
• 2021 USPSTF Guideline:
• The USPSTF recommends screening for colorectal cancer in all adults aged 50 to 75 years (Grade A).
• The USPSTF recommends screening for colorectal cancer in all adults aged 45 to 49 years (Grade B).

Type 2 Diabetes

• 2015 USPSTF Guideline:
• The USPSTF recommends screening for abnormal blood glucose as part of cardiovascular risk assessment in adults aged 40 to 70 years who are overweight or obese.

• 2015 USPSTF Systematic Review:
• Screening for diabetes did not improve mortality rates after 10 years of follow-up. (not yet published as a recommendation)

• 2012 CTFPHC Guideline:
• Ask about symptoms of diabetes: unusual thirst, frequent urination, weight change (gain or loss), extreme fatigue or lack of energy, blurred vision, frequent and recurring infections, cuts and bruises that are slow to heal, and/or tingling or numbness in the hands or feet.
• FINDRISC Diabetes Risk Calculator to distinguish low-, moderate- and high-risk patients.
• Recommendation to not screen in low-risk, 3-5 yearly in moderate-risk and annually in high-risk patients.
• Major risk factors include: WC > 102cm, BMI > 30, age > 55, gestational diabetes, first- or second-degree relative.

Hepatitis C

• 2020 USPSTF Guideline:
• The USPSTF recommends screening for HCV infection in adults aged 18 to 79 years. (B recommendation)

HIV

• 2019 USPSTF Guideline:
• We recommend screening for HIV infection in adolescents and adults aged 15 to 65 years. Younger adolescents and older adults who are at increased risk of infection should also be screened. (A recommendation)
• We recommend screening for HIV infection in all pregnant persons, including those who present in labor or at delivery whose HIV status is unknown. (A recommendation)


• 2019 USPSTF Guidelines for PrEP:
• We recommend that clinicians offer preexposure prophylaxis (PrEP) with effective antiretroviral therapy to patients at high risk of HIV acquisition (A recommendation) (must be confirmed HIV negative prior to offering)

Hyperlipidemia (Dyslipidemia)

• 2015 CFP Simplified Lipid Guideline:
• In patients without CVD (primary prevention), we suggest non-fasting lipid testing as part of global CVD risk estimation in men at age ≥40 years and women at age ≥50 years (moderate-level evidence).
• Testing can be considered earlier for patients with known traditional CVD risk factors including, but not limited to, hypertension, family history of premature CVD, diabetes, and smoking (low-level evidence).
• Repeat screening: For patients not taking lipid-lowering therapy, we suggest lipid testing as part of global CVD risk estimation, performed no more than every 5 years (moderate-level evidence).
• Framingham Risk Calculator

• 2016 Canadian Cardiovascular Society Guideline:
• Screen every 5 years, starting at 40yo for both men and women. Screen yearly if FRS ≥ 5%, continue screening 5 yearly if FRS < 5%.
• Framingham Risk Calculator
• Modified Framingham Risk Score Calculator (as recommended by CCS)
• CVD Risk Equivalents that imply FRS > 20% and require treatment:
  • Clinical Atherosclerosis
  • Most diabetes, including age ≥ 40; age ≥ 30 and 15 years' duration; microvascular disease
  • AAA
  • CKD (eGFR ≤ 45 or ACR ≥ 30 or (eGFR ≤ 60 and ACR ≥ 3))

• 2016 USPSTF Guideline:
• Consider use of a low- or moderate-dose statin if ALL 3 conditions met:
• • patient is 40-75 years old,
  • has at least one CVD risk factor (i.e. dyslipidemia, diabetes, hypertension, smoking), and
  • has a calculated 10-year risk score of a CVD event of 10% or better (i.e. using Framingham).

Hypertension

• 2012 CTFPHC Guideline:
• We recommend blood pressure measurement at all appropriate primary care visits.


• 2020 Hypertension Canada Guideline:
• Health care professionals who have been specifically trained to measure BP accurately should assess BP in all adult patients at all appropriate visits to determine cardiovascular risk and monitor antihypertensive treatment (Grade D).
• BP should be measured regularly in children 3 years of age and older by a health care professional using standardized pediatric techniques (Grade D).

Intimate Partner Violence

• 2018 USPSTF Guideline:
• The USPSTF recommends that clinicians screen for IPV in women of reproductive age and provide or refer women who screen positive to ongoing support services. (B recommendation)

Lung Cancer

• 2016 CTFPHC Guideline:
• For adults aged 55-74 years with at least a 30 pack-year smoking history who currently smoke or quit less than 15 years ago, we recommend annual screening with low-dose CT (LDCT) up to three consecutive times. Screening should ONLY be carried out in health care settings with expertise in early diagnosis and treatment of lung cancer.

• 2021 USPSTF Guideline:
• The USPSTF recommends annual LDCT for all smokers aged 55 years to 80 years who have a 20 pack-year smoking history and currently smoke or have quit within the past 15 years. Screening should be discontinued once a person has not smoked for 15 years or develops a health problem that substantially limits life expectancy or the ability or willingness to have curative lung surgery. [pubmed].

• 18% of all lung cancers found are slow-growing and will not cause symptoms or harm during an average 6.4 years of follow-up. [aafp.org]

Osteoporosis

• 2018 USPSTF Guideline:
• The USPSTF recommends screening for osteoporosis with bone measurement testing to prevent osteoporotic fractures in women 65 years and older.
• The USPSTF recommends screening for osteoporosis with bone measurement testing to prevent osteoporotic fractures in postmenopausal women younger than 65 years who are at increased risk of osteoporosis, as determined by a formal clinical risk assessment tool.


• 2010 Osteoporosis Canada Guideline:
• From age 50, assess 10-year risk with: FRAX WHO Fracture Risk Assessment Tool for Canada +/- BMD measurement
• Indications for BMD measurement:
  • Age ≥ 65 yr
  • Clinical risk factors for fracture (menopausal women, men age 50–64 yr)
  • Fragility fracture after age 40 yr
  • Prolonged use of glucocorticoids (>3 months of prednisone 7.5mg OD)
  • Use of other high-risk medications
  • Parental hip fracture
  • Vertebral fracture or osteopenia identified on radiography
  • Current smoking
  • High alcohol intake
  • Low body weight (< 60 kg) or major weight loss (> 10% of body weight at age 25 yr)
  • Rheumatoid arthritis
• Treat those with a high 10-year risk (>20%), consider treatment for those who are moderate risk (>10%).
• Let fracture risk (not bone density) be the trigger for considering treatment.

Obstructive Sleep Apnea

• It is probably reasonable to screen for OSA using the very brief STOPBANG Questionnaire.
• Male patients over the age of 50 have 2 points on the questionnaire already, but broad population-based screening based on specific criteria such an age cut-off has yet to be studied (although the USPSTF has a research plan).

Prostate Cancer

• 2014 CTFPHC Guideline:
• Recommends against screening with PSA in men aged 55+. DRE is not recommended.


• 2018 USPSTF Guideline:
• Recommends counselling men, 55 to 69 years, on the risks and potential benefits of undergoing periodic PSA–based screening for prostate cancer. Clinicians should not screen men who, after adequate informed consent, do not express a preference for screening
• 2017 CUA Guideline:
• The CUA suggests offering PSA screening to men with a life expectancy greater than 10 years. The decision of whether or not to pursue PSA screening should be based on shared decision-making after the potential benefits and harms associated with screening have been discussed.
• For men electing to undergo PSA screening, we suggest that the intervals between testing should be individualized based on previous PSA levels:
  • a. For men with PSA <1 ng/ml, repeat PSA testing every four years
  • b. For men with PSA 1–3 ng/ml, repeat PSA testing every two years
  • c. For men with PSA >3 ng/ml, consider more frequent PSA testing intervals or adjunctive testing strategies


• Note: Canadian, American, and European guidelines all differ after looking at the same evidence — no strong consensus.
• Other guidelines / references:
  • Ontario Health Guidelines for Prostate Cancer Screening

Smoking Cessation

• 2021 USPSTF Guideline:
• Recommends that clinicians ask all adults about tobacco use, advise them to stop using tobacco, and provide behavioral interventions and FDA-approved pharmacotherapy for cessation to nonpregnant adults who use tobacco. (A recommendation).


• Recommends that clinicians ask all pregnant persons about tobacco use, advise them to stop using tobacco, and provide behavioral interventions for cessation to pregnant persons who use tobacco. (A recommendation).

STIs (Chlamydia & Gonorrhea)

• 2021 CTFPHC Guideline:
• We recommend opportunistic screening of sexually active individuals under 30 years of age who are not known to belong to a high-risk group, annually, for chlamydia and gonorrhea at primary care visits, using a self- or clinician-collected sample (conditional recommendation; very low-certainty evidence).