Effects of 105 biological, socioeconomic, behavioural, and environmental factors on the risk of SARS-CoV-2 infection and a severe course of Covid-19: A prospective longitudinal study

Abstract

The confirmed number of SARS-CoV-2 infections up to 30 August 2021 is 217 mil. worldwide but information about factors affecting the probability of infection or of a severe course of Covid-19 remains insufficient and often speculative. Only a small number of factors have been rigorously examined, mostly by retrospective or cross-sectional studies. We ran a preregistered study on 5,164 internet users who shared with us information about their exposure to 105 risk factors and reported being Covid negative before the beginning of the fourth wave of Covid-19 in the Czech Republic. After the fourth wave, in which 709 (13.7%) of participants were infected, we used a partial Kendall test controlled for sex, age, and urbanisation to compare the risk of infection and of a severe course of the disease in subjects who originally did and did not report exposure to particular risk factors. After the correction for multiple tests, we identified 13 factors - including male sex, lower age, blood group B, and the larger household size - that increased the risk of infection and 16 factors - including mask wearing, borreliosis in the past, use of vitamin D supplements, or rooibos drinking - that decreased it. We also identified 23 factors that increased the risk of a severe course of Covid-19 and 12 factors that decreased the risk.

The effects of 105 biological, socioeconomic, behavioral, and environmental factors on the risk of SARS-CoV-2 infection and a severe course of COVID-19: a prospective, explorative cohort study

“…Statistical analyses were performed with the R version 3.3.1 software [ 13 ]. To compute partial Kendall correlation (controlled for the effects of sex, age, urbanization level, and in some analyses also for reported intensity of anxiety and depression), contingency table tests, and t tests, we used the Explorer package [ 14 ]. Correction for multiple tests was done using the Benjamini–Hochberg procedure with a false discovery rate preset to 0.20 [ 15 ].…”

“…After a transformation between τ and d [ 17 ], τ 0.062, 0.156, and 0.241 correspond to d 0.20 (small effect), 0.50 (medium effect), and 0.80 (large effect), respectively. The dataset is available in the public repository Figshare https://doi.org/10.6084/m9.figshare.16529184 [ 18 ].…”

Measures for Ensuring Sustainability during the Current Spreading of Coronaviruses in the Czech Republic

“…The predominant part of the offensive measures presented below has resulted from the brainstorming of opinions and experience by the implementation team. Consultation with and materials by experts in the fields of developmental biology, parasitology, epidemiology and virology [45][46][47][48][49][50][51] have been also used, including information provided by the Ministry of the Interior of the Czech Republic (2021) [42], the Ministry of Health of the Czech Republic [43] and the National Institute of Public Health (2021) [13].…”