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ObjectivesWe aimed to analyze factors impacting the Covid-19 epidemic on a macro level, comparing multiple countries across the world, and verifying the occurrence at a micro level through cluster analysis.DesignStatistical analysis of large datasets.MethodsWe used publicly available large world datasets (1-11). Data was transformed to fit parametric distributions prior to statistical analyses, which were performed with Student’s t-test, linear regression and post-hoc tests. Especially for ordinary least squares regression, natural logarithmic transformations were done to remediate normality violations in the standardized residuals.ResultsThe severity of the epidemic was most strongly related to exposure to ultraviolet light and extrapolated levels of vitamin D and to the health of the population, especially with regards to obesity. We found no county with an obesity level < 8% with a severe epidemic. We also found that countries where the population benefited from sun exposure or vitamin D supplementation and spent time outside fared well. Factors related to increased propagation of the virus included the use of heating ventilation and air conditioning (HVAC), population density, poorly aerated gatherings, relative humidity, timely policies of closing clustering places until aeration was improved, and daily amount of ridership on public transportation, especially subways. Population lockdowns, masks, and blood type did not provide much explanatory power. The excess mortality observed is within the ranges of severe past influenza epidemics of 2016/2017 or 1999/2000.ConclusionsOur study suggested that prevention measures should be directed to improving aeration systems, enhancing diets and exercise, and ensuring adequate levels of vitamin D. Further research on masking is indicated as our study could not separate policies from how well they were actually followed.FundingThis research received no specific grant from any funding agency in the public, commercial or not-for-profit sectors’Strengths and Limitations of the StudyThe Study examines large datasets across countries to look for macrotrends in management of the Covid-19 outbreak.The Study cannot necessarily establish causation but rather correlation.The Study raises some novel possibilities for further studies in relation to country-wide and individual-level susceptibility to Covid-19 and to other epidemics in general.The Study raises questions about some political policies based upon country-level comparisons and suggests some areas for exploration of prevention policies. |
