Canadian Medical Association

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DynaMed presents the top-ten EBM pearls of 2022 (in chronological order) selected from 2022 issues of the EMB Focus newsletter for their clinical impact and newsworthiness. 

1. What does it take to keep weight off? Apparently more than $665

Practice Point: Restricted calorie diets don’t work in the long term, not even with a $665 financial incentive.

EBM Pearl: A self-selected enrollment process recruits already motivated participants. This is a form of selection bias which overestimates benefit in favor of the intervention.

2. Unmasking COVID in children

Practice Point: Masking in schools may only offer a small magnitude of benefit, if any, and one that may be further diminished in a vaccinated population.

EBM Pearl: When evidence is limited, communication about clinical recommendations should be done with humility, acknowledging the limits of existing evidence and reliance on expert opinion where evidence does not exist.

3. Surviving overdiagnosis in breast cancer

Practice Point: One in seven women diagnosed with breast cancer through screening will be unnecessarily treated as a result of overdiagnosis.

EBM Pearl: Overdiagnosis is a form of lead-time bias which artificially inflates survival rates

4. Tracking fracking for birth outcomes

Practice Point: Close proximity to fracking wells and for longer periods of time seems like a bad thing for fetuses in-utero.

EBM Pearl: Observational cohorts and case studies are subject to a lot of confounding. This makes proving causality due to an environmental exposure especially difficult.

5. Intermittent fasting: metabolic hack or mind trick for weight loss?

Practice Point: The addition of time-restriction to calorie limits on eating may not result in additional weight loss, but either method might be a safe and sustainable way to lose about 15lbs in a year.

EBM Pearl: ‘Proving’ that an intervention works requires statistically different event rates between groups, which requires events to occur. This can be harder to do when you select a very healthy population to study.

6. Please take the sunshine away: Vitamin D Still doesn’t work for primary fracture prevention

Practice Point: Stop recommending vitamin D for primary prevention to the general population.

EBM Pearl: A secondary analysis of a large trial can provide extra information, but results won’t have the same level of certainty as the prespecified analysis.

7. Re-use old drugs [for COVID] quickly, while they still work!

Practice Point: Don’t use fluvoxamine, metformin or ivermectin for patients with COVID unless they have depression, diabetes or a parasite.

EBM Pearl: Science doesn't change its mind. New information brings us closer to the truth. (And DynaMed can help you keep up!)

8. The subtle sufficiency of “insufficient” recommendations

Practice Point: Interventions for screen-detected type 2 diabetes in children and adolescents have not (yet?) been shown to improve health outcomes. Current evidence is insufficient to recommend screening.

EBM Pearl: An “I” statement from the USPSTF does not stand for “I don’t know.” Take the time to critically consider more strongly worded recommendations from other groups when the USPSTF concludes that the evidence is insufficient.

9. Psilocybin may not be safe or offer a long-term benefit for treatment-resistant depression

Practice Point: A treatment that offers a small, short-term benefit but that comes with a significant risk of (self-)harm is unlikely to take flight.

EBM Pearl: Minimally important clinical difference (MCID) is an important factor for interpreting scaled outcomes like depression scores.

10. Big news: Lecanemab offers small benefit for Alzheimer’s dementia

Practice Point: While there are sure to be patients and families begging for this new Alzheimer’s treatment, temper expectations by explaining that the magnitude of benefit may be very small with a real risk of harm.

EBM Pearl: In this trial, the very small p value indicates consistency of effect, not a large magnitude of effect.


CMA members have access to DynaMed, a point-of-care reference tool valued at US$399 per year, as part of their membership.

Do you have a question on these or other clinical topics? Contact the Ask a Librarian team to request a literature search.


About the author(s)

Written by Katharine DeGeorge, MD, MS, Deputy Editor at DynaMed and Associate Professor of Family Medicine at the University of Virginia.

Edited by Alan Ehrlich, MD, Executive Editor at DynaMed and Associate Professor in Family Medicine at the University of Massachusetts Medical School; Dan Randall, MD, Deputy Editor at DynaMed; Nicole Jensen, MD, Family Physician at WholeHealth Medical; Vincent Lemaitre, PhD, Senior Medical Writer at DynaMed; and Sarah Hill, MSc, Associate Editor at DynaMed.

DynaMed is a clinician-focused tool designed to facilitate efficient and evidence-based patient care. Rigorous, daily review of medical literature by physician and specialist staff ensures timely and objective analysis, synthesis and guidance. DynaMed includes drug content from Micromedex, Canadian and international guidelines, and clinical images. CMA members have access to DynaMed, a point-of-care tool, included with their membership ― a tool valued at US$399 a year.

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