BIOMECHANICS STUDENT’S LEARNING AND PERCEPTIONS OF LEARNING DUE TO THE COVID-19 PANDEMIC AND ASSOCIATED MITIGATION

The purpose of this study was to assess the effects of the COVID-19 pandemic and associated mitigation protocols on student learning and perceptions of learning in a biomechanics course. Students (n=31) enrolled in a three credit-hour biomechanics class in the Spring 2022 semester participated. Six questions related to the effects of mitigation protocols on student perceptions of learning. Three questions asked about to course-related student behaviours. Learning scores (g) were similar to those previously reported. Students believed that mitigation negatively affected getting to know and communicate with classmates (\u3e50%), they had to implement different learning strategies (55%), and learning mathematical concepts was more difficult due to the instructor wearing a face covering (45%). The student learning environment should be a consideration when deciding what mitigation protocols to implement if proposed in the future

When do Default Nudges Work?

Nudging is a burgeoning topic in science and in policy, but evidence on the effectiveness of nudges among differentially-incentivized groups is lacking. This paper exploits regional variations in the roll-out of the Covid-19 vaccine in Sweden to examine the effect of a nudge on groups whose intrinsic incentives are different: 16-17-year-olds, for whom Covid-19 is not dangerous, and 50-59-year-olds, who face a substantial risk of death or severe disease. The response is strong in the younger but absent in the older age group, consistent with the theory that nudges work best for choices that are not meaningful to the individual.Comment: 20 page

A hierarchical Bayesian model for estimating age-specific COVID-19 infection fatality rates in developing countries

The COVID-19 infection fatality rate (IFR) is the proportion of individuals infected with SARS-CoV-2 who subsequently die. As COVID-19 disproportionately affects older individuals, age-specific IFR estimates are imperative to facilitate comparisons of the impact of COVID-19 between locations and prioritize distribution of scare resources. However, there lacks a coherent method to synthesize available data to create estimates of IFR and seroprevalence that vary continuously with age and adequately reflect uncertainties inherent in the underlying data. In this paper we introduce a novel Bayesian hierarchical model to estimate IFR as a continuous function of age that acknowledges heterogeneity in population age structure across locations and accounts for uncertainty in the estimates due to seroprevalence sampling variability and the imperfect serology test assays. Our approach simultaneously models test assay characteristic, serology, and death data, where the serology and death data are often available only for binned age groups. Information is shared across locations through hierarchical modeling to improve estimation of the parameters with limited data. Modeling data from 26 developing country locations during the first year of the COVID-19 pandemic, we found seroprevalence did not change dramatically with age, and the IFR at age 60 was above the high-income country benchmark for most locations

Differential COVID-19 infection rates in children, adults, and elderly: Systematic review and meta-analysis of 38 pre-vaccination national seroprevalence studies

Background Debate exists about whether extra protection of elderly and other vulnerable individuals is feasible in COVID-19. We aimed to assess the relative infection rates in the elderly vs the non-elderly and, secondarily, in children vs adults.Methods We performed a systematic review and meta-analysis of seroprevalence studies conducted in the pre-vaccination era. We identified representative nation-al studies without high risk of bias through SeroTracker and PubMed searches (last updated May 17, 2022). We noted seroprevalence estimates for children, non-elderly adults, and elderly adults, using cut-offs of 20 and 60 years (or as close to these ages, if they were unavailable) and compared them between dif-ferent age groups.Results We included 38 national seroprevalence studies from 36 different coun-tries comprising 826 963 participants. Twenty-six of these studies also includ-ed pediatric populations and twenty-five were from high-income countries. The median ratio of seroprevalence in elderly vs non-elderly adults (or non-elderly in general, if pediatric and adult population data were not offered separately) was 0.90-0.95 in different analyses, with large variability across studies. In five studies (all in high-income countries), we observed significant protection of the elderly with a ratio of <0.40, with a median of 0.83 in high-income countries and 1.02 elsewhere. The median ratio of seroprevalence in children vs adults was 0.89 and only one study showed a significant ratio of <0.40. The main limitation of our study is the inaccuracies and biases in seroprevalence studies.Conclusions Precision shielding of elderly community-dwelling populations be-fore the availability of vaccines was indicated in some high-income countries, but most countries failed to achieve any substantial focused protection.Registration Open Science Framework (available at: https://osf.io/xvupr

Age-stratified infection fatality rate of COVID-19 in the non-elderly population

The largest burden of COVID-19 is carried by the elderly, and persons living in nursing homes are particularly vulnerable. However, 94% of the global population is younger than 70 years and 86% is younger than 60 years. The objective of this study was to accurately estimate the infection fatality rate (IFR) of COVID-19 among non -elderly people in the absence of vaccination or prior infection. In systematic searches in SeroTracker and PubMed (protocol: https://osf.io/xvupr), we identified 40 eligible national seroprevalence studies covering 38 countries with pre-vaccination seroprevalence data. For 29 countries (24 high-income, 5 others), publicly available age -stratified COVID-19 death data and age-stratified seroprevalence information were available and were included in the primary analysis. The IFRs had a median of 0.034% (interquartile range (IQR) 0.013-0.056%) for the 0-59 years old population, and 0.095% (IQR 0.036-0.119%) for the 0-69 years old. The median IFR was 0.0003% at 0-19 years, 0.002% at 20-29 years, 0.011% at 30-39 years, 0.035% at 40-49 years, 0.123% at 50-59 years, and 0.506% at 60-69 years. IFR increases approximately 4 times every 10 years. Including data from another 9 countries with imputed age distribution of COVID-19 deaths yielded median IFR of 0.025-0.032% for 0-59 years and 0.063-0.082% for 0-69 years. Meta-regression analyses also suggested global IFR of 0.03% and 0.07%, respectively in these age groups. The current analysis suggests a much lower pre-vaccination IFR in non -elderly populations than previously suggested. Large differences did exist between countries and may reflect differences in comorbidities and other factors. These estimates provide a baseline from which to fathom further IFR declines with the widespread use of vaccination, prior infections, and evolution of new variants

On the Concept and Ethics of Vaccination for the Sake of Others

This dissertation explores the idea and ethics of vaccination for the sake of others. It conceptually distinguishes four different kinds of vaccination—self-protective, paternalistic, altruistic, and indirect—based on who receives the primary benefits of vaccination and who ultimately makes the vaccination decision. It describes the results of focus group studies that were conducted to investigate what people who might get vaccinated altruistically think of this idea. It also applies the different kinds of vaccination to ethical issues surrounding COVID-19, such as lockdown measures, routine or mandatory vaccination of healthy children, and the ethical justification of restrictive measures for unvaccinated people. A more general philosophical account of vaccination ethics is ultimately developed, which is based not on moral duties, but on the moral reasons that people may have to get vaccinated for the sake of others. It is argued that such reasons may be stronger or weaker, depending on various factors related to the vaccines in question and the specific epidemiological circumstances