Association of country-wide coronavirus mortality with demographics, testing, lockdowns, and public wearing of masks (Update August 4, 2020)

Abstract

<jats:p>Background. There is wide variation between countries in per-capita mortality from COVID-19 (caused by the SARS-CoV-2 virus). Determinants of this variation are not fully understood. Methods. Potential predictors of per-capita coronavirus-related mortality in 198 countries were examined, including age, sex ratio, obesity prevalence, temperature, urbanization, smoking, duration of infection, lockdowns, viral testing, contact tracing policies, and public mask-wearing norms and policies. Multivariable linear regression analysis was performed. Results. In univariate analyses, the prevalence of smoking, per-capita gross domestic product, urbanization, and colder average country temperature were positively associated with coronavirus-related mortality. In a multivariable analysis of 194 countries, the duration of infection in the country, and the proportion of the population 60 years of age or older were positively associated with per-capita mortality, while duration of mask-wearing by the public was negatively associated with mortality (all p&lt;0.001). The prevalence of obesity was independently associated with mortality in models which controlled for testing levels or policy. International travel restrictions were independently associated with lower per-capita mortality, but other containment measures and viral testing and tracing policies were not. In countries with cultural norms or government policies supporting public mask-wearing, per-capita coronavirus mortality increased on average by just 7.2% each week, as compared with 55.0% each week in remaining countries. On multivariable analysis, lockdowns tended to be associated with less mortality (p=0.41), and increased per-capita testing with higher reported mortality (p=0.55), though neither association was statistically significant. Conclusions. Societal norms and government policies supporting the wearing of masks by the public, as well as international travel controls, are independently associated with lower per-capita mortality from COVID-19.</jats:p>

Positive association between COVID-19 deaths and influenza vaccination rates in elderly people worldwide

“…4 and 5). Leffler et al (2020) reported in a global study that internal lockdown requirements were not associated with mortality, but that in countries that recommended use of face masks early on at the national level, the COVID-19 death rate was lower than expected.…”

Commentary: Physiological and Psychological Impact of Face Mask Usage during the COVID-19 Pandemic

“…More quality studies from scientists will help support public health officials when they are encouraging or mandating mask wearing. More data continues to emerge supporting the use of masks; for example, one recent study examined the different sources of variation among over 200 countries in per-capita mortality due to COVID-19, and reported that duration of mask wearing by the public was negatively associated with mortality [ 64 ]. Thus, masks may be here to stay for the foreseeable future and may not just have application for COVID-19, but for severe flu seasons and for potential future respiratory epidemics/pandemics.…”

Properties of materials considered for improvised masks

“…This highlights the need for public health measures that can be applied very widely to prevent widespread community transmission. Research is increasingly suggesting that masks, including non-medical masks, may be able to significantly reduce COVID-19 transmission (Eikenberry, et al, 2020;Stutt, et al, 2020;Leung, et al, 2020;Leffler, et al, 2020) and led the World Health Organization (WHO) and Center for Disease Control (CDC) to recommend universal facial covering and mask use for the general public. At the same time, the global reach of the pandemic saw a shortage of personal protective equipment for healthcare providers, requiring conservation of the supply of N95 respirators and surgical masks for the healthcare providers.…”