Original Research

Proper Use and Compliance of Facial Masks During the COVID-19 Pandemic: An Observational Study of Hospitals in New York City

Author and Disclosure Information

Proper mask usage is a cornerstone of the prevention of COVID-19 transmission. Hospitals, in particular, are important settings for proper mask compliance due to the risk for viral exposure. Despite the presence of health care personnel and financial resources to ensure proper compliance, mask usage is variable in health care settings. The impact of mask compliance is particularly important in New York City (NYC) because of the burden of COVID-19 and at-risk demographics. We conducted a prospective observational study in 4 NYC hospitals assessing rates of proper mask compliance among adult patients entering the hospital. Six hundred unique individuals were observed for proper mask fit, exposure of the nose and mouth, and the presence of nontraditional face coverings in lieu of a mask at 4 NYC hospitals. Proper mask usage is a large health education gap that must be addressed by health care administrations and governmental agencies, as mask usage continues to be an effective form of COVID-19 prevention.

Practice Points

  • Enormous financial and human resources have been utilized by health care systems to prevent the spread of COVID-19 in health care settings, including universal temperature checks, clinical symptom triage, and masking policies. Despite these mitigation practices, mask noncompliance continues to be a major problem in hospitals.
  • Mask compliance among 600 individuals entering 4 New York City hospitals was observed to be 78%, despite months of policies for universal masking and the city’s high mortality rates during the first COVID-19 wave.
  • Masks have been shown to reduce the spread of COVID-19, and proper mask compliance is an important issue that must be addressed by health care administrations and governmental agencies.



Although the universal use of masks by both health care professionals and the general public now appears routine, widely differing recommendations were distributed by different health organizations early in the pandemic. In April 2020, the World Health Organization (WHO) stated that there was no evidence that healthy individuals wearing a medical mask in the community prevented COVID-19 infection.1 However, these recommendations must be placed in the context of a national shortage of personal protective equipment early in the pandemic. The WHO guidance released on June 5, 2020, recommended continuous use of masks for health care workers in the clinical setting.2 Additional recommendations included mask replacement when wet, soiled, or damaged, and when the wearer touched the mask. The WHO also recommended mask usage by those with underlying medical comorbidities and those living in high population–density areas and in settings where physical distancing was not possible.2

The Centers for Disease Control and Prevention (CDC) officially recommended the use of face coverings for the general public to prevent COVID-19 transmission on April 3, 2020.3 The CDC highlighted that masks should not be worn by children younger than 2 years; individuals with respiratory compromise; and patients who are unconscious, incapacitated, or unable to remove a mask without assistance.4 Medical masks and respirators were only recommended for health care workers. Importantly, masks with valves/vents were not recommended, as respiratory droplets can be emitted, defeating the purpose of source control.4 New York State mandated mask usage in public places starting on April 15, 2020.

These recommendations were based on the hypothesis that COVID-19 transmission occurs primarily via droplets and contact. In reality, SARS-CoV-2 transmission more likely occurs in a continuum from larger droplets to miniscule aerosols expelled from an infected person when talking, coughing, or sneezing.5,6 It should be noted that there was a formal suggestion of the potential for airborne transmission of SARS-CoV-2 by the CDC in a statement on September 18, 2020, that was subsequently retracted 3 days later.7,8 The CDC, reversing their prior recommendations, updated their guidance on October 5, 2020, endorsing prior reports that SARS-CoV-2 can be spread through aerosol transmission.8

Mask usage helps prevent viral spread by all individuals, especially those who are presymptomatic and asymptomatic. Presymptomatic individuals account for approximately 40% to 60% of transmissions, and asymptomatic individuals account for approximately 4% to 30% of infections by some models, which suggest these individuals are the drivers of the pandemic, more so than symptomatic individuals.9-15 Additionally, masking also may in effect reduce the amount of SARS-CoV-2 to which individuals are being exposed in the community.14 Universal masking is a relatively low-cost, low-risk intervention that may provide moderate benefit to the individual but substantial benefit to communities at large.10-13 Universal masking in other countries also has clearly demonstrated major benefits during the pandemic. Implementation of universal masking in Taiwan resulted in only approximately 440 COVID-19 cases and less than 10 deaths, despite a population of 23 million.16 South Korea, having experience with Middle East respiratory syndrome, also was able to quickly institute a mask policy for its citizens, resulting in approximately 94% compliance.17 Moreover, several mathematical models have shown that even imperfect use of masks on a population level can prevent disease transmission and should be instituted.18

Given the importance and potential benefits of mask usage, we investigated compliance and proper utilization of facial masks in New York City (NYC), once the epicenter of the pandemic in the United States. New York City and the rest of New York State experienced more than 1.13 million and 1.46 million cases of COVID-19, respectively, as of early November 2021.19 Nationwide, NYC had the greatest absolute death count of more than 34,634 and the greatest rate of death per 100,000 individuals of 412. In contrast, New York State, excluding NYC, had an absolute death count of more than 21,646 and a death rate per 100,000 individuals of 195 as of early November 2021.19 Now entering 20 months since the first case of COVID-19 in NYC, it continues to be vital for facial mask protocols to be emphasized as part of a comprehensive infection prevention protocol, especially in light of continued vaccine resistance, to help stall continued spread of SARS-CoV-2.20

We seek to show that despite months of policies for universal masking in NYC, there is still considerable mask noncompliance by the general public in health care settings where the use of masks is particularly imperative. We conducted an observational study investigating proper use of face masks of adults entering the main entrance of 4 hospitals located in NYC.


We observed mask usage in adults entering 4 hospitals in September 2020 (postsurge in NYC and prior to the availability of COVID-19 vaccinations). Hospitals were chosen to represent several types of health care delivery systems available in the United States and included a city, state, federal, and private hospital. Data collection was completed during peak traffic hours (8:00 am to 12:00 pm) on a weekday and continued until a total of 100 unique patients were observed at each site. Each hospital entrance was barricaded, and hospital staff were stationed at these entry points to take each individual’s temperature, screen for symptoms and exposure risk, verify patients’ appointments, and ensure proper mask wearing (in optimal circumstances). Data collectors (J.L. and N.M.) were stationed just past the barricade of each hospital’s entrance and observed those who entered. Individuals were not approached about the study, demographics, or the use and/or views about usage of facial masks. Children and hospital employees were excluded from data collection, with the exception of 1 hospital with a dedicated employee entrance where employees were observed for mask compliance. Except for vented/valved masks or makeshift masks fashioned out of scarfs, bandanas, or similar materials, the type of mask an individual wore was not distinguished (medical masks, cotton masks, or respirator-type masks were not differentiated).


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