Introduction
The severe acute respiratory syndrome coronavirus 2 (SARS-COV-2) pandemic that begun in the Chinese province of Hubei quickly became a global threat [
1]. As of December 1st 2020, the virus has infected more than 62.8 million individuals worldwide and caused almost 1.5 million deaths [
2]. With no effective pharmacological interventions or universal access to the vaccine, other modes of prevention are the best approaches to control the disease spread [
3,
4].
Strategies to transition out of lockdown [
5,
6], carried out in many countries, need to take into account both symptomatic and asymptomatic individuals in spreading SARS-CoV-2 from person-to-person through close contact [
7,
8]. Protective equipment measures are needed [
9,
10].
Either disposable surgical masks or reusable cotton ones are protective. Wearing masks in public places is seen as an important contribution to containing viral spread, especially when physical distancing is not possible or unpredictable [
10]. Locations include stores and other shopping areas, workplaces, health care facilities (i.e. surgeries, hospitals, care-homes etc.), public transport, busy sidewalks, and households. If used widely and corresponding to risk, masks can reduce viral transmission. Benefits increase where exposure risk is high and are marginal where it is low [
9,
10].
In the beginning of the pandemic, mask-wearing was controversial among leading health organizations, such as the World Health Organization (WHO) [
11]. However, convinced by the evidence, the WHO has broadened its recommendations for use during the pandemic since June 5th, 2020 and advises that in areas where the virus is spreading, people should wear masks when social distancing is not possible [
12,
13]. The US Centers for Disease Control and Prevention (CDC) has also modified previous recommendations, suggesting that, together with infected persons and health care workers, healthy people “should wear cloth face coverings in public settings when around people outside of their household” [
14,
15].
The European Centre for Disease Control (ECDC) recommends use in the community, especially when visiting busy, closed spaces [
16]. Formal guidance from the ECDC has informed official advice in many countries. As more was understood about asymptomatic transmission, governments were more inclined to mandate wearing and facilitate access. The latter was possible through various initiatives such as the provision of templates or instructions for citizens on how to make cloth masks at home, together with boosting domestic production or access to shops selling fabric and in supermarkets [
17].
Different regulations have been in place in central Europe since the epidemic began, including Poland, Slovakia and Czechia [
17,
18]. In many countries wearing became mandatory outside the home as part of physical distancing measures under lockdowns. In some other countries masks have been introduced as part of transition measures universally or in certain circumstances, such as on public transport or where physical distancing is not possible. In remaining countries, wearing is recommended, but not mandatory, as part of transitional measures [
17].
In Poland, obligatory mask wearing was not introduced in the initial phase of the pandemic. On April 10
h, 2020, 6 weeks after the country’s first laboratory confirmed SARS-Cov-2 case had been reported, a new control measure was announced [
19]. It became obligatory to cover one’s nose and mouth in public spaces; any form of face covering was acceptable [
18]. A relaxation of previous universal measures regarding wearing masks was announced on May 29th, 2020, limiting use to shopping areas, health care facilities, care-homes, public transport and churches [
19]. The obligation to wear masks in indoor and outdoor public spaces has been restored since October 10th, 2020 [
20].
Reports on use of masks by the general public as a preventive measure to limit transmission are scant, especially in European countries. Therefore, the objective of this study was to assess use of masks or other protective devices in public spaces in Poland during the epidemic and to evaluate influencing determinants.
Methods
In Poland, mandatory face covering in public spaces was introduced in the beginning of April, 2020 [
18]. In the end of May, 2020, it was limited to indoor public spaces [
19]. A non-participatory covert observational study was carried out during three occasions over a period of three consecutive weeks (10.05.2020, 18.05.2020, 25.05.2020) among the general public in Poland from the different risk areas regarding SARS-Cov-2 pandemic. The risk classification was adapted from a report made by the Ministry of Health on basic reproductive number (R) estimates [
21]: high-risk areas (R > 1); low-risk areas (R 0.5–1.0); very low-risk areas (R < 0.5).
According to the latest census, Poland has a population of 38,383,000 [
22]. The representative target sample size needed to achieve the study objectives and sufficient statistical power was calculated with a sample size calculator [
23]. This arrived at 664 participants, using a margin of error of ±5%, a confidence level (CI) of 99% and a 50% response distribution.
At 2 pm, at each time point described above, eighty two 4th year medical students observed ten consecutive individuals of > 4 years of age while venturing out into public spaces (820 observations per time point) which were divided into two categories: open/enclosed space. The age frame > 4 years was arbitrarily chosen due to the governmental regulation requiring mask use for children older than 4 years and adults [
18]. Two types of public spaces were chosen arbitrarily: 1. representing open space, i.e. “sidewalks/parks” and 2. representing enclosed space - “shopping centers”. Three activities were observed: walking, outdoor sport activities and shopping. Students were randomly selected to make observations outdoors (75% observations) and indoors (25% observations). All 4th year medical students from the University of Zielona Gora, Poland, participated in the study collecting the relevant data. Trained students used a validated structured checklist, as recommended by “WHO guidelines on the use of masks in the context of COVID-19” [
24]. Rational use of a mask was defined as wearing a specific type of mask (N95 respirator, medical mask, cloth mask, face shield or other – a scarf/bidon). The correct manner of masks use in the public was defined as the use of masks as per the WHO/ECDC guidelines [
16,
24]. Observations were carried out in student residence locations without the knowledge of those observed (covert).
Statistical analysis
Field notes were taken at observation points. Next, data were entered to MS Excel 2013. Data quality was assured by the review of data completeness by the research team (OP and MG). Data were validated using STATISTICA PL Version 12.5 (StatSoft Inc., 2016). Our main outcome was mask usage. For socio-demographic variables, gender was coded as one for males, and two for females. A place of residence variable was arbitrarily divided into 2 categories: a city up to 50,000 citizens and > 50,000 citizens; a region regarding pandemic risk – into: high-risk (R > 1) and low-risk/very low-risk areas (R ≤ 1.0); a type of activity observed – into playing sports/other activities. A bivariate analysis assessed the demographic characteristics (gender, residency and region regarding pandemic risk), together with the participant location during the observation (open/closed space), and the type of activity observed, associated with the outcome variable. The categorical variable groups were compared using the chi-square test with Yates correction and Fisher’s exact test. For observations made at each of the 3 time points, standard single-outcome logistic regression models were built for the predicted outcome variable (mask usage); all models were then reduced by the use of a stepwise selection and a backward procedure [
25] with the help of R software [
26]. Unstandardized regression coefficients in the regression model were used to assess any change in the model. A change in coefficients was compared and used to determine any variable change. For binary data the exponent of the coefficient is interpreted as the odds ratio (OR) [
27].
Conclusions
The results show an essential difference in how the general public responds to the SARS-Cov-2 pandemic in the context of mask usage. Practices were found to be inadequate, especially among males, and tended to decrease over time, more significantly among those wearing cloth masks than when compared to those wearing N95 respirators. This message can be used to target specific vulnerable groups when developing public health campaigns which should be then rigorously evaluated for their effectiveness. Among those using masks, every third individual wore them incorrectly. Therefore, awareness campaigns regarding the need for the proper usage of face masks - by utilizing all communication channels available - would be helpful during this pandemic [
46]. The results may also help policy makers to adequately tailor mask usage strategies to better prevent SARS-Cov-2 transmission. Finally, political leaders should act as role models and set a good example wearing masks in the public arena to create a sense of solidarity and make a gesture with regards to evidence based practices.
In conclusion, this study identified topics that may need attitudinal modification to improve self-protection against SARS-Cov-2 infection and community spread of the virus. There is now an ideal moment to implement these adjustments.
Acknowledgements
Authors want to thank all 4th year medical students of the University of Zielona Gora (UZ) who enthusiastically participated in the study. Additional thanks to Joanna Michalska and Jakub Szczepański, 4th year medical students, UZ, for their help in literature search. Special thanks to prof. Peter Barss, a Clinical Professor at the School of Population and Public Health, University of British Columbia in Vancouver, Canada, for language corrections.
Open AccessThis article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit
http://creativecommons.org/licenses/by/4.0/. The Creative Commons Public Domain Dedication waiver (
http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated in a credit line to the data.
Publisher’s Note
Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.