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Living Practice Points from ACP: Advice on Use of N95, Surgical, and Cloth Masks to Prevent COVID-19

Philadelphia, PA (June 18, 2020) – The American College of Physicians (ACP) issued new Practice Points on the effectiveness of N95 respirators, surgical masks, and cloth masks for the prevention of COVID-19 disease in addition to standard precautions (such as hand washing, gloves, etc.) in both healthcare settings and community settings. “Use of N95, Surgical, and Cloth Masks to Prevent COVID-19 in Health Care and Community Settings: Living Practice Points From the American College of Physicians (Version 1),” was published today in Annals of Internal Medicine.

The ACP Practice Points provide rapid clinical advice based on the best available evidence, a rapid and living systematic evidence review conducted by the Pacific Northwest Evidence-based Practice Center (EPC) and funded by Agency for Healthcare Research and Quality (AHRQ).

In healthcare settings, the direct evidence is insufficient to evaluate the effectiveness and comparative effectiveness of various types of respirators or masks for preventing SARS-CoV2 infection. ACP based its Practice Points on indirect evidence on other types of coronaviruses, influenza or influenza-like infection, and other respiratory infections in order to inform the practice points in the healthcare settings. ACP says that healthcare personnel should wear N95 respirators when in close contact with suspected or known COVID-19 patients. ACP also says that all healthcare personnel, patients, and visitors who are not in close contact with patients with suspected or known COVID-19 should use surgical masks in healthcare settings to reduce the risk of transmission of SARS-CoV-2 infection.

Currently, there is no direct evidence evaluating the effectiveness and comparative effectiveness of various types of respirators or masks for preventing SARS-CoV2 infection in community settings. Low-certainty evidence exists that mask use may reduce the risk for SARS-CoV-1 infection compared with no mask use in the community, but a major limitation of the studies is that they did not specify mask type. ACP relied on low to moderate certainty indirect evidence on how N95 respirators, surgical masks, and cloth masks perform against each other to reduce the transmission of other types of coronaviruses, influenza or influenza-like infection, and other respiratory infections in order to inform the practice points in the community setting. Those infections include SARS-CoV-1, Middle East respiratory syndrome coronavirus (MERS-CoV), influenza-like or other respiratory viruses.

ACP says asymptomatic or symptomatic persons in community settings should follow community and statewide public health guidelines for mask use, which should take into account factors such as local demographics (e.g., high risk populations), epidemiologic data (e.g., reproduction rate, daily case counts, hospitalizations, and deaths), and exposure context (e.g., number of people, indoor vs outdoors, ventilation etc.). The Practice Points highlight the importance of handling masks appropriately to avoid self-contamination, and that even when wearing a mask, it remains critical to take other infection prevention precautions and control procedures to prevent and reduce transmissions. A person who interacts with many people such as flight attendants, restaurant servers, grocery workers, cab drivers and others may benefit from wearing a surgical or cloth mask. However, the use of masks is not necessary when at home, unless a household member has COVID-19. ACP also notes that it is important for clinicians and public health authorities to educate individuals and communities on the appropriate use and disposal of masks, which includes how to put on and remove the mask.

“It’s important to note that lack of direct evidence does not mean that masks are effective or are not effective,” said Jacqueline W. Fincher, MD, MACP, president, ACP. “We will continue to monitor this and update these Practice Points as new evidence becomes available. In the meantime, we support following proper precautions and procedures to reduce infection transmissions.”

ACP emphasizes that regardless of the use of N95 respirators, surgical or cloth masks, it is essential in any setting to follow all other infection prevention and control procedures to slow and reduce transmissions, including physical distancing, self-isolation, quarantine, frequent hand hygiene, covering cough and sneezes using a bent elbow or paper tissue, refraining from touching mouth, eyes, or nose, and frequent cleaning and disinfecting.

ACP Practice Points are developed by ACP’s Scientific Medical Policy Committee and provide advice to improve the health of individuals and populations and promote high value care based on the best available evidence derived from assessment of scientific work (e.g. clinical guidelines, systematic reviews, individual studies). ACP Practice Points aim to address population health and clinical topics, and consider known determinants of health, including but not limited to genetic variability, environment, and lifestyle.

The ACP Practice Points will be maintained as a “living” document and ACP’s Scientific Medical Policy Committee will monitor emerging evidence to determine its impact on the main findings and conclusions, and issue updates as needed.  The AHRQ EPC report will also be updated as a “living” review.

Contact: Andrew Hachadorian, (215) 351-2514, AHachadorian@acponline.org


About the American College of Physicians
The American College of Physicians is the largest medical specialty organization in the United States with members in more than 145 countries worldwide. ACP membership includes 159,000 internal medicine physicians (internists), related subspecialists, and medical students. Internal medicine physicians are specialists who apply scientific knowledge and clinical expertise to the diagnosis, treatment, and compassionate care of adults across the spectrum from health to complex illness. Follow ACP on Twitter, Facebook, and Instagram.