Global age-sex-specific mortality, life expectancy, and population estimates in 204 countries and territories and 811 subnational locations, 1950–2021, and the impact of the COVID-19 pandemic: a comprehensive demographic analysis for the Global Burden of Disease Study 2021

Background Estimates of demographic metrics are crucial to assess levels and trends of population health outcomes. The profound impact of the COVID-19 pandemic on populations worldwide has underscored the need for timely estimates to understand this unprecedented event within the context of long-term population health trends. The Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2021 provides new demographic estimates for 204 countries and territories and 811 additional subnational locations from 1950 to 2021, with a particular emphasis on changes in mortality and life expectancy that occurred during the 2020–21 COVID-19 pandemic period. Methods 22 223 data sources from vital registration, sample registration, surveys, censuses, and other sources were used to estimate mortality, with a subset of these sources used exclusively to estimate excess mortality due to the COVID-19 pandemic. 2026 data sources were used for population estimation. Additional sources were used to estimate migration; the effects of the HIV epidemic; and demographic discontinuities due to conflicts, famines, natural disasters, and pandemics, which are used as inputs for estimating mortality and population. Spatiotemporal Gaussian process regression (ST-GPR) was used to generate under-5 mortality rates, which synthesised 30 763 location-years of vital registration and sample registration data, 1365 surveys and censuses, and 80 other sources. ST-GPR was also used to estimate adult mortality (between ages 15 and 59 years) based on information from 31 642 location-years of vital registration and sample registration data, 355 surveys and censuses, and 24 other sources. Estimates of child and adult mortality rates were then used to generate life tables with a relational model life table system. For countries with large HIV epidemics, life tables were adjusted using independent estimates of HIV-specific mortality generated via an epidemiological analysis of HIV prevalence surveys, antenatal clinic serosurveillance, and other data sources. Excess mortality due to the COVID-19 pandemic in 2020 and 2021 was determined by subtracting observed all-cause mortality (adjusted for late registration and mortality anomalies) from the mortality expected in the absence of the pandemic. Expected mortality was calculated based on historical trends using an ensemble of models. In location-years where all-cause mortality data were unavailable, we estimated excess mortality rates using a regression model with covariates pertaining to the pandemic. Population size was computed using a Bayesian hierarchical cohort component model. Life expectancy was calculated using age-specific mortality rates and standard demographic methods. Uncertainty intervals (UIs) were calculated for every metric using the 25th and 975th ordered values from a 1000-draw posterior distribution. Findings Global all-cause mortality followed two distinct patterns over the study period: age-standardised mortality rates declined between 1950 and 2019 (a 62·8% [95% UI 60·5–65·1] decline), and increased during the COVID-19 pandemic period (2020–21; 5·1% [0·9–9·6] increase). In contrast with the overall reverse in mortality trends during the pandemic period, child mortality continued to decline, with 4·66 million (3·98–5·50) global deaths in children younger than 5 years in 2021 compared with 5·21 million (4·50–6·01) in 2019. An estimated 131 million (126–137) people died globally from all causes in 2020 and 2021 combined, of which 15·9 million (14·7–17·2) were due to the COVID-19 pandemic (measured by excess mortality, which includes deaths directly due to SARS-CoV-2 infection and those indirectly due to other social, economic, or behavioural changes associated with the pandemic). Excess mortality rates exceeded 150 deaths per 100 000 population during at least one year of the pandemic in 80 countries and territories, whereas 20 nations had a negative excess mortality rate in 2020 or 2021, indicating that all-cause mortality in these countries was lower during the pandemic than expected based on historical trends. Between 1950 and 2021, global life expectancy at birth increased by 22·7 years (20·8–24·8), from 49·0 years (46·7–51·3) to 71·7 years (70·9–72·5). Global life expectancy at birth declined by 1·6 years (1·0–2·2) between 2019 and 2021, reversing historical trends. An increase in life expectancy was only observed in 32 (15·7%) of 204 countries and territories between 2019 and 2021. The global population reached 7·89 billion (7·67–8·13) people in 2021, by which time 56 of 204 countries and territories had peaked and subsequently populations have declined. The largest proportion of population growth between 2020 and 2021 was in sub-Saharan Africa (39·5% [28·4–52·7]) and south Asia (26·3% [9·0–44·7]). From 2000 to 2021, the ratio of the population aged 65 years and older to the population aged younger than 15 years increased in 188 (92·2%) of 204 nations. Interpretation Global adult mortality rates markedly increased during the COVID-19 pandemic in 2020 and 2021, reversing past decreasing trends, while child mortality rates continued to decline, albeit more slowly than in earlier years. Although COVID-19 had a substantial impact on many demographic indicators during the first 2 years of the pandemic, overall global health progress over the 72 years evaluated has been profound, with considerable improvements in mortality and life expectancy. Additionally, we observed a deceleration of global population growth since 2017, despite steady or increasing growth in lower-income countries, combined with a continued global shift of population age structures towards older ages. These demographic changes will likely present future challenges to health systems, economies, and societies. The comprehensive demographic estimates reported here will enable researchers, policy makers, health practitioners, and other key stakeholders to better understand and address the profound changes that have occurred in the global health landscape following the first 2 years of the COVID-19 pandemic, and longer-term trends beyond the pandemic

Does Long-term Exposure to Traffic-Related Particulate Matter Air Pollution Increase the Risk of Coronary Artery Disease?

Traffic-related air pollution levels have consistently been associated with increased overall mortality and morbidity. Effects of exposure to particulate matter (PM) on the heart have been of particular interest, as the elevation of fine particulates (PM₂.₅) has shown strongest association with increased risk of myocardial infarction, as well as ischemic cardiovascular disease, possibly via accelerated atherosclerosis. The objective of this paper is to gather currently available evidence on whether long-term exposure to elevated traffic-related PM₂.₅ increases the risk of developing coronary artery diseases, as measured through indicators of atherosclerosis. The population of interest is urban adults who are not diagnosed with cardiovascular disease. Since the entire urban population is exposed to at least some level of PM₂.₅, comparisons were made between individuals who were exposed to different levels of PM₂.₅ on a continuous scale. Course name: Epidemiological Methods 1Medicine, Faculty ofPopulation and Public Health (SPPH), School ofUnreviewedGraduat

Cellular Therapy for Saccular Intracranial Aneurysms: A Proof-of-Concept Study

Intracranial aneurysms are pathological dilations of arteries in the brain. Rupture of an aneurysm would be catastrophic, resulting in death in half of the cases and permanent neu- rological deficits in half of the survivors. The current standard-of-care for treating aneurysms is endovascular coiling, a procedure that involves packing the aneurysm with soft platinum- made coils that cause the blood within the aneurysm to clot, consequently slowing the flow of blood into the aneurysm. This is followed by a healing response that remodels the clot into fibrous tissue and regenerates a neointima layer that covers the neck of the aneurysm and isolates it from the parent vessel. Lack of proper healing in about one-fifth of the patients results in recurrence of the aneurysm. Building on a growing body of literature, this project evaluated the potential therapeutic effects of mesenchymal stem/stromal cells (MSCs) on the healing of coiled aneurysms in a rabbit model.2 year

Epi-Cease : A Non-Invasive Closed-Loop Transcranial Direct Current Stimulation (tDCS)-based Device for Antiepileptic Drug Resistant Epilepsy

Epilepsy is a chronic neurological disorder characterized by recurrent and unprovoked seizures due to abnormal electrical activity in the brain. Unfortunately, this disorder affects 50 million people worldwide and of all ages, making it the fourth most common neurological disorder. As a result, epilepsy reduces an individual’s quality of life and provides a challenge for family members and caregivers. Over the last few decades, many advances have been made in effectively treating and controlling epilepsy. Today, a focused history, physical examination, blood work, and video-EEG are all part of the standard protocol in the accurate and timely diagnosis of epilepsy. Once the epileptic etiology is identified, anti-epileptic drugs (AED) represent a first-line pharmacological treatment for these patients. Unfortunately, a portion of patients do not respond to multiple AEDs and may display dose-dependent side effects that warrant AED discontinuation. These patients are considered for neurosurgical intervention after case and extensive review. Many centres, including Vancouver General Hospital, employ temporal lobectomy for focal temporal lobe epilepsies. This procedure is quite effective for a small portion of patients but is highly invasive and can lead to complications in verbal memory in 0.4-4% of patients. More importantly, brain surgery is not for all patients and can only be applied to patients suffering from temporal lobe seizures. The goal of this proposal is to “non-invasively reduce the frequency, duration and/or severity of seizures in drug-resistant focal epilepsy patients”. Particularly, we set out to circumvent the highly invasive nature of brain surgery and its limited widespread use. Moreover, we wished to develop a technology that would non-invasively “abort” seizures in real-time. Our proposed solution, Epi-Cease, is a non-invasive closed-looped system that consists of a wearable head-strap tDCS (transcranial direct-current stimulation) that delivers non-invasive stimulation to abort a seizure. This device will communicate with an Apple Watch that will detect seizures based on motion sensing and physiological data. When detecting the onset of a seizure, the Apple Watch app will signal the tDCS module to deliver stimulation to the brain in real-time in order to suppress/abort seizure initiation.To assess the safety and efficacy of Epi-Cease, we will conduct a two-staged proof-of-concept study. First, we will validate the Apple Watch motion-sensing and physiological data app compared to traditional methods of epilepsy monitoring. Once validated, we will then recruit a small cohort (n=3) of low-risk epilepsy patients to test the technology before expansion. This technology would represent a quantum leap forward in the care of epilepsy patients as it would be the first, real-time non-invasive solution to abort seizures and effectively control focal epilepsies. Course name: Applied PathophysiologyApplied Science, Faculty ofUnreviewedGraduat

Classification of Streaming Fuzzy DEA Using Self-Organizing Map

The classification of fuzzy data is considered as the most challenging areas of data analysis and the complexity of the procedures has been obstacle to the development of new methods for fuzzy data analysis. However, there are significant advances in modeling systems in which fuzzy data are available in the field of mathematical programming. In order to exploit the results of the researches on fuzzy mathematical programming, in this study, a new fuzzy data classification method based on data envelopment analysis (DEA) is provided when fuzzy data are imported as a stream. The proposed method can classify data that changes are created in their behavioral pattern over time using updating the criteria of predicting fuzzy data class. To reduce computational time, fuzzy self-organizing map (SOM) is used to compress incoming data. The new method was tested by simulated data and the results indicated the feasibility of this technique in the face of uncertain and variable conditions

Evaluation of green lean production in textile industry: a hybrid fuzzy decision-making framework

Textile industry is an old and effective industry in Iran. However, due to its age and high energy consumption, this industry has low profitability and entrepreneurship. One of the most important problems of the weaving industry is the issue of waste regarding manpower, materials, machinery, and especially energy consumption. Another problem is environmental pollution. In this paper, using a multiple decision-making model for ranking and selecting criteria and sub-criteria, which is presented using the step-wise weight assessment ratio analysis (SWARA) and also by examining several industrial plants on weaving, the final ranking was performed using the fuzzy COPRAS method. According to the final result and using the opinions of experts and reviewing the studied cases, the environmental criterion was more important than other criteria, and also according to the existing sub-criteria, the amount of CO2 production and pH in the process of completion and washing and the types of pollution in the effluent and sewage were more important than other sub-criteria. Also, among the alternatives, company 5 is evaluated as the best alternative

An Engineers-in-Scrubs Design Project

International Heat, a team of five graduate students, spent the past four months designing a thermal cautery system capable of being used for open abdominal surgery in low-resource settings. Throughout those four months, the team followed the design process outlined in Biodesign: The Process of Innovating Medical Technologies. Potential project ideas were presented to the entire Engineers-in-Scrubs class. International Heat formed from a desire to create a device with the potential to significantly impact the quality of medical care in third world countries. This report details the team’s progression starting with defining the team’s mission statement and strategic focus, to the needs finding process, to needs screening and creation of preliminary needs specifications, to concept generation and screening, to interviewing clinicians who provided feedback leading to the update of the needs statement and needs specifications, and then final concept selection. We describe the prototyping of and evaluation of two separate concepts in order to ultimately choose thermal cautery as well as extensive feasibility testing we performed to see if thermal cautery had the potential to be a viable alternative to an electrosurgical unit. Finally, we provide a potential development strategy which could be implemented to bring the thermal cautery unit to market.Applied Science, Faculty ofMechanical Engineering, Department ofUnreviewedGraduat

Seroprevalence of COVID-19 in Blood Donors: A Systematic Review and Meta-Analysis

Introduction. Determining the prevalence of SARS-CoV-2 in blood donors makes the control of virus circulation possible in healthy people and helps implement strategies to reduce virus transmission. The purpose of the study was to examine the seroprevalence of COVID-19 in blood donors using systematic review and meta-analysis. Materials and Methods. The electronic databases PubMed, Scopus, Web of Science, and the Google Scholar search engine were searched using standard keywords up to 2022-04-26. The variance of each study was calculated according to the binomial distribution. Studies were combined according to the sample size and variance. Q Cochrane test and I2 index were used to examine the heterogeneity of the studies. Data analysis was performed in STATA 14 software, and the significance level of the tests was P < 0.05. Results. In the 28 papers examined with 227894 samples, the seroprevalence of COVID-19 in blood donors was 10 (95 CI: 9, 11), estimated 5 (95 CI: 4, 7) among men and 6 (95 CI: 4, 7) among women. This rate in different blood groups was as follows: A 12 (95 CI: 10-14), B 12 (95 CI: 10-15), AB 9 (95 CI: 7-12), and O 13 (95 CI: 11-16). The seroprevalence of COVID-19 in blood donors in North America 10, Europe 7, Asia 23, South America 5, and Africa was 4; Moreover, the seroprevalence of IgG antibodies was estimated to be 23 (95 CI: 18-29) and IgM 29 (95 CI: 9-49). Conclusion. The highest prevalence of COVID-19 serum in women blood donors was among blood group O and Asia. The seroprevalence of IgG and IgM antibodies was high too