Top 20 Research Studies of 2020 for Primary Care Physicians


Am Fam Physician. 2021 Jul ;104(1):41-48.

  Related letter: Should Muscle Relaxants Be Used as Adjuvants in Patients With Acute Low Back Pain?

Published online June 9, 2021.

Author disclosure: Dr. Grad has no relevant financial affiliations. Dr. Ebell is cofounder and editor-in-chief of Essential Evidence Plus; see Editor's Note.

This article summarizes the top 20 research studies of 2020 identified as POEMs (patient-oriented evidence that matters), including the two most highly rated guidelines of the year on gout and chronic obstructive pulmonary disease (COPD). Regarding COVID-19, handwashing and social distancing through stay-at-home orders or quarantine measures are effective at slowing the spread of illness. Use of proper face masks (not gaiters or bandanas) is also effective at preventing transmission. This is important because the virus can infect others during the presymptomatic phase. Aspirin can no longer be recommended for the primary prevention of cardiovascular disease. Human papillomavirus vaccination is strongly associated with reduced risk of invasive cervical cancer, especially in women who were vaccinated before 17 years of age. When a woman who is postmenopausal has a screening bone mineral density test, rechecking the test after three years does not help to identify those who will have a fragility fracture. A higher daily step count is associated with lower all-cause mortality. After one year of follow-up, physical therapy is preferred to glucocorticoid injections for osteoarthritis of the knee; acetaminophen is ineffective for acute low back pain or pain due to knee or hip osteoarthritis; and adding a muscle relaxant to ibuprofen does not improve functional outcomes or pain in people reporting moderate to severe back pain one week after starting treatment. Although short-term antibiotics and steroids are effective in treating acute exacerbations of COPD, not much else is. Successful communication with patients seeking an antibiotic for a flulike illness can be achieved with combinations of messaging, including information on antibiotic resistance and the self-limiting nature of the illness. A new prediction rule effectively identifies patients with a history of penicillin allergy who have a low likelihood of positive findings on allergy testing. Low-value screening tests in asymptomatic, low-risk patients often lead to further testing, diagnostic procedures, or referrals. A new tool helps determine the amount of change needed to signify a real difference between two laboratory values in the same person over time. Finally, a pillar of our specialty, continuity of care, is associated with decreased all-cause mortality.

Annually for 22 years, a team of clinicians has systematically reviewed English-language medical journals to identify original research most likely to change and improve primary care practice. The team includes experts in family medicine, pharmacology, hospital medicine, and women's health.1,2

The goal of this process is to identify POEMs (patient-oriented evidence that matters). A POEM must report at least one patient-oriented outcome, such as improvement in symptoms, morbidity, or mortality. It should also be free of important methodologic bias, making the results valid and trustworthy. Finally, if applied in practice, the results would change what some physicians do by prompting them to adopt a new practice or discontinue an old one that has been shown to be ineffective or harmful. Adopting POEMs in clinical practice should improve patient outcomes. Of more than 20,000 research studies published in 2020 in the journals reviewed by the POEMs team, 306 met criteria for validity, relevance, and practice change. These POEMs are emailed daily to subscribers of Essential Evidence Plus (Wiley-Blackwell, Inc.).

The Canadian Medical Association purchases a POEMs subscription for its members, many of whom receive the daily POEM. As these physicians read a POEM, they can rate it using a validated questionnaire. This process is called the Information Assessment Method ( POEM ratings address the domains of clinical relevance, cognitive impact, use of this information in practice, and expected health benefits if that POEM is applied to a specific patient.3,4 In 2020, each of the 306 daily POEMs was rated by an average of 1,230 physicians.

In this article, we present the 20 most clinically relevant POEMs as rated by Canadian Medical Association members in 2020. This is the 10th installment of our annual series ( As we write this article, the pandemic rolls on. However, beyond COVID-19, our patients continue to face the usual (and unusual) health problems of everyday life. Thus, we summarize the clinical question and bottom-line answer for research studies identified as a top 20 POEM, organized by topic and followed by a brief discussion. This set of 20 POEMs includes the two most relevant practice guidelines of the year. The full POEMs are available online at


The year 2020 saw the emergence of SARS-CoV-2, a novel coronavirus

The Authors

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ROLAND GRAD, MD, MSc, is an associate professor in the Department of Family Medicine at McGill University, Montreal, Quebec, Canada....

MARK H. EBELL, MD, MS, is a professor in the Department of Epidemiology at the University of Georgia, Athens.

Address correspondence to Roland Grad, MD, MSc, 3755 Cote Sainte Catherine Rd., Montreal, Quebec, Canada H3T 1E2 (email: Reprints are not available from the authors.

Author disclosure: Dr. Grad has no relevant financial affiliations. Dr. Ebell is cofounder and editor-in-chief of Essential Evidence Plus; see Editor's Note.


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1. Shaughnessy AF, Slawson DC, Bennett JH. Becoming an information master: a guidebook to the medical information jungle. J Fam Pract. 1994;39(5):489–499....

2. Ebell MH, Barry HC, Slawson DC, et al. Finding POEMs in the medical literature. J Fam Pract. 1999;48(5):350–355.

3. Grad RM, Pluye P, Mercer J, et al. Impact of research-based synopses delivered as daily e-mail: a prospective observational study. J Am Med Inform Assoc. 2008;15(2):240–245.

4. Pluye P, Grad RM, Johnson-Lafleur J, et al. Evaluation of email alerts in practice: part 2. Validation of the information assessment method. J Eval Clin Pract. 2010;16(6):1236–1243.

5. Little P, Stuart B, Hobbs FDR, et al. An internet-delivered handwashing intervention to modify influenza-like illness and respiratory infection transmission (PRIMIT): a primary care randomised trial [published correction appears in Lancet. 2015;386(10004):1630]. Lancet. 2015;386(10004):1631–1639.

6. Nussbaumer-Streit B, Mayr V, Dobrescu AI, et al. Quarantine alone or in combination with other public health measures to control COVID-19: a rapid review. Cochrane Database Syst Rev. 2020;(4):CD013574.

7. Lyu W, Wehby GL. Comparison of estimated rates of coronavirus disease 2019 (COVID-19) in border counties in Iowa without a stay-at-home order and border counties in Illinois with a stay-at-home order. JAMA Netw Open. 2020;3(5):e2011102.

8. Ebell MH, Bagwell-Adams G. Mandatory social distancing associated with increased doubling time: an example using hyperlocal data. Am J Prev Med. 2020;59(1):140–142.

9. Fischer EP, Fischer MC, Grass D, et al. Low-cost measurement of face mask efficacy for filtering expelled droplets during speech. Sci Adv. 2020;6(36):eabd3083.

10. He X, Lau EHY, Wu P, et al. Temporal dynamics in viral shedding and transmissibility of COVID-19 [published correction appears in Nat Med. 2020;26(9):1491–1493]. Nat Med. 2020;26(5):672–675.

11. Oran DP, Topol EJ. Prevalence of asymptomatic SARSCoV-2 infection: a narrative review. Ann Intern Med. 2020;173(5):362–367.

12. Moriarty F, Ebell MH. A comparison of contemporary versus older studies of aspirin for primary prevention. Fam Pract. 2020;37(3):290–296.

13. Saint-Maurice PF, Troiano RP, Bassett DR Jr, et al. Association of daily step count and step intensity with mortality among US adults. JAMA. 2020;323(12):1151–1160.

14. Crandall CJ, Larson J, Wright NC, et al. Serial bone density measurement and incident fracture risk discrimination in postmenopausal women. JAMA Intern Med. 2020;180(9):1232–1240.

15. Lei J, Ploner A, Elfström KM, et al. HPV vaccination and the risk of invasive cervical cancer. N Engl J Med. 2020;383(14):1340–1348.

16. Deyle GD, Allen CS, Allison SC, et al. Physical therapy versus glucocorticoid injection for osteoarthritis of the knee. N Engl J Med. 2020;382(15):1420–1429.

17. Jüni P, Hari R, Rutjes AWS, et al. Intra-articular corticosteroid for knee osteoarthritis. Cochrane Database Syst Rev. 2015;(10):CD005328.

18. Saragiotto BT, Abdel Shaheed C, Maher CG. Paracetamol for pain in adults. BMJ. 2019;367:l6693.

19. Friedman BW, Irizarry E, Solorzano C, et al. A randomized, placebo-controlled trial of ibuprofen plus metaxalone, tizanidine, or baclofen for acute low back pain. Ann Emerg Med. 2019;74(4):512–520.

20. Friedman BW, Dym AA, Davitt M, et al. Naproxen with cyclobenzaprine, oxycodone/acetaminophen, or placebo for treating acute low back pain: a randomized clinical trial. JAMA. 2015;314(15):1572–1580.

21. Dobler CC, Morrow AS, Beuschel B, et al. Pharmacologic therapies in patients with exacerbation of chronic obstructive pulmonary disease: a systematic review with meta-analysis. Ann Intern Med. 2020;172(6):413–422.

22. Roope LSJ, Tonkin-Crine S, Herd N, et al. Reducing expectations for antibiotics in primary care: a randomised experiment to test the response to fear-based messages about antimicrobial resistance. BMC Med. 2020;18(1):110.

23. Trubiano JA, Vogrin S, Chua KYL, et al. Development and validation of a penicillin allergy clinical decision rule. JAMA Intern Med. 2020;180(5):745–752.

24. Bouck Z, Calzavara AJ, Ivers NM, et al. Association of low-value testing with subsequent health care use and clinical outcomes among low-risk primary care outpatients undergoing an annual health examination. JAMA Intern Med. 2020;180(7):973–983.

25. McCormack JP, Holmes DT. Your results may vary: the imprecision of medical measurements. BMJ. 2020;368:m149.

26. Baker R, Freeman GK, Haggerty JL, et al. Primary medical care continuity and patient mortality: a systematic review. Br J Gen Pract. 2020;70(698):e600–e611.

27. Kokorovic A, So AI, Hotte SJ, et al. A Canadian framework for managing prostate cancer during the COVID-19 pandemic: recommendations from the Canadian Urologic Oncology Group and the Canadian Urological Association. Can Urol Assoc J. 2020;14(6):163–168.

28. FitzGerald JD, Dalbeth N, Mikuls T, et al. 2020 American College of Rheumatology Guideline for the Management of Gout [published correction appears in Arthritis Rheumatol. 2021;73(3):413]. Arthritis Rheumatol. 2020;72(6):879–895.

29. Nici L, Mammen MJ, Charbek E, et al. Pharmacologic management of chronic obstructive pulmonary disease. An official American Thoracic Society Clinical Practice Guideline [published correction appears in Am J Respir Crit Care Med. 2020;202(6):910]. Am J Respir Crit Care Med. 2020;201(9):e56–e69.

POEMs are provided by Essential Evidence Plus, a point-of-care clinical decision support system published by Wiley-Blackwell, Inc. For more information, visit



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