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 (https://www.mcgill.ca/iam). 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 (https://www.aafp.org/afp/toppoems). 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 https://www.aafp.org/afp/poems2020.

COVID-19

The year 2020 saw the emergence of SARS-CoV-2, a novel coronavirus that causes the COVID-19 illness, and 54 POEMs addressed the epidemiology, diagnosis, treatment, and prognosis of patients with COVID-19. Not surprisingly, the four most highly rated POEMs of the year and five in the top 20 provided evidence regarding preventive measures (Table 1).^5–10 These were published early in the pandemic and provided important evidence for family physicians to share with their patients.

The most highly rated POEM was originally published in 2015 and reissued in 2020 after the content was updated for COVID-19. The study was a large pragmatic trial in the United Kingdom that randomized participants to a brief online hand-washing intervention or usual care. Those who completed the intervention had fewer respiratory tract infections over the next four months (51% vs. 59%; P < .001; number needed to treat = 12).⁵

The next COVID-19 POEM was a Cochrane review.⁶ The authors reviewed the results of modeling studies of COVID-19 and previous coronavirus pandemics, as well as four observational studies. They concluded that quarantine measures are effective in slowing the spread of infection, especially when implemented early and in conjunction with other public health measures.

The third POEM summarized the results of two ecologic studies. The first compared COVID-19 incidence rates in eight Iowa counties that did not have stay-at-home orders with seven neighboring Illinois counties that had such orders in place.⁷ The second compared a Georgia county that implemented stay-at-home orders approximately two weeks before the rest of Georgia with seven surrounding counties.⁸ In both studies, earlier implementation of stay-at-home orders was associated with a lower incidence of COVID-19.

Another POEM summarized the results of one of the earliest studies to evaluate the effectiveness of different kinds of masks for preventing the spread of respiratory droplets.⁹ Using laser technology, 14 types of masks were evaluated. Gaiters and bandanas were essentially useless, polypropylene and surgical masks were much better, and N95 masks were best.

An important factor in the rapid spread of COVID-19 was transmission by asymptomatic people. One of the first publications to report this was described in the next POEM. Chinese researchers studying infector-infectee transmission pairs found that the peak of infectiousness occurs about one day before symptom onset, and that 44% of secondary cases occur during the presymptomatic period.¹⁰ Another study (not among the top 20 POEMs) reviewed cohorts in which the entire group was tested for COVID-19 during an outbreak and found that the rates of asymptomatic or presymptomatic infection are 75% or higher in young adult populations and approximately 40% overall.¹¹

Prevention and Screening

POEMs addressing prevention topics are summarized in Table 2.^12–15 The first was a meta-analysis of randomized trials comparing aspirin with placebo as primary prevention. It compared four studies that recruited patients since 2005, with older studies that largely recruited patients in the 1980s and 1990s. The newer studies no longer found that patients taking aspirin for primary prevention have significant reductions in cancer incidence or mortality, cardiovascular mortality, or nonfatal myocardial infarction. Any benefits were countered by harms, such as increased gastrointestinal bleeding.¹² Perhaps we are doing a better job of screening for cancer and preventing cardiovascular events through use of statins and antihypertensives, lessening the need for aspirin in prevention.

We often tell our patients to walk more, but does walking affect mortality? The next POEM used data from a national sample of U.S. residents whose daily steps were measured between 2003 and 2006.¹³ All-cause mortality was 77 per 1,000 person-years for those with less than 4,000 steps per day; 21 per 1,000 for those with 4,000 to 7,999 steps per day; 7 per 1,000 for those with 8,000 to 11,999 steps per day; and 4.8 per 1,000 for those with at least 12,000 steps per day. Step intensity was not significantly associated with mortality after controlling for total daily steps. Bottom line? Higher step counts are associated with lower all-cause mortality, suggesting our patients should keep walking.¹³

When a woman who is postmenopausal has a screening bone mineral density test, the question arises about whether to repeat the test and, if so, how often? The third POEM in this group is a cohort study from the Women's Health Initiative, which showed that information gained from a second test three years after the first does not add predictive value beyond the first test result. Because bone density changes little over time, one bone mineral density test at around 65 years of age is likely to be sufficient for the purpose of screening to prevent a fragility fracture.¹⁴

Studies have shown that human papillomavirus (HPV) vaccination can reduce the likelihood of precancerous abnormalities identified on a Papanicolaou (Pap) test. The next POEM is a Swedish study that used data from a national health registry to compare the risk of invasive cervical cancer in 527,871 vaccinated women vs. 1,145,112 unvaccinated women.¹⁵ After adjusting for differences between groups, the incidence rate ratio (IRR; the ratio of the incidence of cancer in vaccinated people to that in unvaccinated people) for invasive cervical cancer was 0.37 (95% CI, 0.21 to 0.57). For women who were vaccinated before 17 years of age, the IRR was only 0.12 (95% CI, 0.00 to 0.34), whereas for those vaccinated between 17 and 30 years of age, the IRR was 0.47 (95% CI, 0.27 to 0.75). HPV vaccination is strongly associated with a lower risk of invasive cervical cancer, especially when given early.

Musculoskeletal

Three POEMs addressing musculoskeletal topics are summarized in Table 3.^16–19 The first is a study that randomized adults with knee osteoarthritis to up to three corticosteroid injections or up to eight physical therapy sessions in the first six weeks, with additional sessions as needed.¹⁶ The rapid and large improvement in the first month for both groups is somewhat surprising, with relatively little further improvement the rest of the year. This suggests regression to the mean may have contributed to the observed improvement (i.e., patients were identified when their arthritis was flaring up and would have improved no matter what). Also, the open-label design may have contributed to a Hawthorne effect (alteration of behavior by the participants of a study who know they are being observed) for those in the physical therapy group and a placebo effect for those in the injection group. A Cochrane review concluded that glucocorticoid injections are effective, although primarily in the two to four weeks following injection.¹⁷ Overall, the physical therapy group did better at one year, with continued improvement, whereas the injection group plateaued after the first month.¹⁶

The next POEM is a systematic review of randomized controlled trials of acetaminophen compared with placebo for pain relief in adults.¹⁸ It showed that acetaminophen is more effective than placebo in providing some pain relief in patients with acute migraine and might be more beneficial than placebo (which also works well) for tension headaches. A single dose of acetaminophen is about twice as likely as placebo to reduce postpartum perineal pain, and it may be effective (but not as effective as other treatments) for acute renal colic. Importantly, acetaminophen is ineffective for patients with acute low back pain or pain due to knee or hip osteoarthritis.

The last POEM in this category addresses a drug class often prescribed for back pain. In people with moderate to severe low back pain who are taking a nonsteroidal anti-inflammatory drug, such as ibuprofen (up to 600 mg three times per day), does the addition of a muscle relaxant improve function or reduce pain? No.¹⁹ This finding reminds us of an earlier randomized controlled trial from the same author that was a top POEM of 2015. At that time, we advised not adding cyclobenzaprine to naproxen for patients with acute low back pain.²⁰

Respiratory

Two top POEMs on respiratory topics are summarized in Table 4.^21,22 One is a meta-analysis of randomized controlled trials of treatment in patients with an exacerbation of chronic obstructive pulmonary disease.²¹ This shows that antibiotics and corticosteroids are effective in treating acute exacerbations in outpatient and inpatient settings, regardless of the severity of the exacerbation. Current research does not provide good guidance on which antibiotic is best or on the optimal dose or duration of corticosteroid treatment. Notably, studies performed in critically ill patients were not included in this analysis.

The other POEM addresses the tricky issue of communicating with patients who appear to be seeking an antibiotic for a flulike illness. It is a randomized trial conducted online in the United Kingdom showing that patients receiving the combination of a fear-based message about increased antibiotic resistance and an empowering message are less likely to visit a physician for their next respiratory tract infection (45.1% to 46.1% vs. 29.2%; P < .001) and less likely to request an antibiotic (52.5% to 54.7% vs. 42.3%; P < .001) than those receiving only fear-based messaging.²²

Miscellaneous

Four top POEMs do not fall easily into a single category (Table 5).^23–26 The first is about a new clinical prediction rule to identify patients who report a penicillin allergy but are unlikely to have a true allergy if tested. The FAST rule is as follows—five years or less since the reaction: 2 points; anaphylaxis, angioedema, or severe cutaneous reaction: 2 points; treatment required for reaction: 1 point. Patients with a score of 0 have a less than 1% likelihood of a positive result on allergy testing, and those with a score of 1 or 2 have a 5% likelihood.²³

The COVID-19 pandemic upended medical practice, leading to large reductions in the use of health care services. For example, the Canadian Urological Association recommended the cessation of prostate-specific antigen screening for prostate cancer until the resolution of the pandemic.²⁷ In this context, the next POEM reminds us to avoid low-value screening tests in asymptomatic, low-risk patients because they often lead to further testing, diagnostic procedures, or referrals.²⁴ Specifically, screening tests in low-risk patients, such as chest radiography and electrocardiography in adults as part of an annual health examination and Pap tests in those younger than 21 years or older than 69 years, should be avoided.

How many patients still ask for annual blood tests despite physicians counseling them on the low yield for doing this? The next POEM was the top non–COVID-related POEM of 2020 for clinical relevance.²⁵ This POEM describes a new online tool (https://www.bmj.com/content/368/bmj.m149) to illustrate the variability in a single laboratory value (such as the A1C test) and the amount of change needed to signify a real difference between two values in the same person over time. For example, given the variability inherent in total cholesterol measurements, it is difficult to detect a clinically important change within a one-year period.

Our final miscellaneous POEM is a systematic review of the value of a pillar of family medicine—personal continuity of care. This is defined by an ongoing relationship with a physician that builds the physician-patient relationship and promotes the healing power of interactions. This core principle of family medicine stands up to scientific scrutiny by demonstrating an associated reduction in mortality.²⁶

Practice Guidelines

POEMs sometimes summarize high-impact clinical practice guidelines. Key messages from the two highest rated guidelines, addressing gout and chronic obstructive pulmonary disease, are summarized in Table 6.^28,29

The full text of the POEMs discussed in this article is available at https://www.aafp.org/afp/poems2020.

A list of top POEMs from previous years is available at https://www.aafp.org/afp/toppoems.

Editor's Note: This article was cowritten by Dr. Mark Ebell, deputy editor for evidence-based medicine for AFP and cofounder and editor-in-chief of Essential Evidence Plus, published by Wiley-Blackwell, Inc. Because of Dr. Ebell's dual roles and ties to Essential Evidence Plus, the concept for this article was independently reviewed and approved by a group of AFP's medical editors. In addition, the article underwent peer review and editing by three of AFP's medical editors. Dr. Ebell was not involved in the editorial decision-making process.—Sumi Sexton, MD, Editor-in-Chief

The authors thank Wiley-Blackwell, Inc., for giving permission to excerpt the POEMs; Drs. Allen Shaughnessy, Henry Barry, David Slawson, Nita Kulkarni, and Linda Speer for selecting and writing the original POEMs; the academic family medicine fellows and faculty of the University of Missouri–Columbia for their work as peer reviewers; Joulé, Inc., for supporting the POEMs CME program in Canada; Pierre Pluye, PhD, for codeveloping the Information Assessment Method; and Maria Vlasak for her assistance with copyediting the POEMs.