The Canadian Task Force on Preventive Health Care should not receive high ranking based on AGREEII or GRADE

Editor,

I read with interest, the article by Ren et al. Global guidelines for breast cancer screening: A systematic review [1].

It was a disappointment that the breast cancer screening guideline from the Canadian Task Force on Preventive Health Care (CTF) was ranked highly. Although ranking was according to 6 domains using AGREEII criteria, the authors would not be aware from just reading the guideline paper, that CTF did not follow the spirit/intent of AGREE [2], specifically with respect to Stakeholder Involvement or Rigour of Development and did not follow the GRADE system [3] for determining which evidence to consider.

AGREEII states that the “guideline development group includes individuals from all relevant professional groups.” There were no experts in breast cancer on the CTF panel. They further state that “views and preferences of the target population (patients, public, etc.) have been sought.” The CTF ignored input from advocates for breast density notification. AGREE states, “The guideline has been externally reviewed by experts prior to its publication.” Indeed, many experts did review and criticize the guideline, but their input was ignored by CTF.

GRADE states that although randomized clinical trials (RCTs) generally produce more reliable evidence than observational studies, they also specify that flawed RCTs may be downgraded, and observational studies may be upgraded when they are carefully performed and show large magnitude benefits. CTF included the Canadian National Breast Screening Studies (CNBSS) even though their results suggested compromised randomization [4] which has now been confirmed, and excluded the Pan-Canadian observational study [5], which showed 40% mortality reduction.