Distanciamento social, sentimento de tristeza e estilos de vida da população brasileira durante a pandemia de COVID-19

The COVID-19 pandemic has had biopsychosocial impacts on individual and collective health. The aim of the study was to analyze adherence to social distance, the repercussions on mood and changes in the lifestyles of the Brazilian adult population during the beginning of the COVID-19 pandemic. This is a cross-sectional study with adult individuals living in Brazil (n = 45,161) who participated in the virtual health survey ConVid - Behavior Survey, from April 24 to May 24, 2020. Data collection was performed via web, using a self-administered questionnaire. The prevalence and 95% confidence interval of the studied variables were calculated. Of the sample studied, only 1.5% led normal lives, without any social restrictions and 75% stayed at home, of which 15% stayed strictly at home. The frequent feelings of sadness or depression (35.5%), isolation (41.2%) and anxiety (41.3%) were reported by a large part of the studied population. It was found that 17% of participants reported increased consumption of alcoholic beverages and 34% of smokers increased the number of cigarettes. There was an increase in the consumption of unhealthy foods and a reduction in the practice of physical activity in the period studied. It was concluded that there was a high adherence to social distance and an increase in feelings of sadness, depression and anxiety, as well as an increase in the consumption of unhealthy foods, use of alcoholic beverages and cigarettes and a reduction in the practice of physical activity. These changes are worrying and can result in damage to individual and collective health in the medium and long term.A pandemia de COVID-19 acarretou impactos biopsicossociais à saúde individual e coletiva. O objetivo do estudo foi analisar a adesão ao distanciamento social, as repercussões no estado de ânimo e mudanças nos estilos de vida da população adulta brasileira durante o início da pandemia da COVID-19. Trata-se de estudo transversal com indivíduos adultos residentes no Brasil (n = 45.161) que participaram do inquérito de saúde virtual ConVid - Pesquisa de Comportamentos, no período de 24 de abril a 24 de maio de 2020. A coleta de dados foi realizada via web, utilizando-se de um questionário autopreenchido. Foram calculadas as prevalências e intervalo de 95% de confiança das variáveis estudadas. Da amostra estudada, apenas 1,5% levou vida normal, sem nenhuma restrição social e 75% ficaram em casa, sendo que destes 15% ficaram rigorosamente em casa. Os sentimentos frequentes de tristeza ou depressão (35,5%), isolamento (41,2%) e ansiedade (41,3%) foram reportados por grande parte da população estudada. Verificou-se 17% dos participantes reportaram aumento do consumo de bebidas alcoólicas e de 34% dos fumantes aumentaram o número de cigarros. Observou-se aumento no consumo de alimentos não saudáveis e redução da prática de atividade física no período estudado. Conclui-se que houve elevada adesão ao distanciamento social e aumento dos sentimentos de tristeza, depressão e ansiedade, bem como aumento de consumo de alimentos não saudáveis, uso de bebidas alcóolicas e cigarros e redução da prática de atividade física. Essas mudanças são preocupantes e podem resultar em danos à saúde individual e coletiva a médio e longo prazo. &nbsp

Doenças crônicas não transmissíveis e mudanças nos estilos de vida durante a pandemia de COVID-19 no Brasil

Objective: Compare lifestyle changes before and during the COVID-19 pandemic, according to the presence or absence of chronic noncommunicable diseases (NCDs) in Brazilian adults. Methods: Cross-sectional study, using data from the ConVid survey, between April and May 2020. Variables were evaluated: lifestyle and presence of one or mor NCDs (diabetes, hypertension, respiratory disease, heart disease and cancer). Sociodemographic characteristics were used as adjustment. Relative frequencies and confidence intervals (CI) of 95% of the explanatory variables were calculated before and during the pandemic. For the comparison of groups, with or without NCDs for changes in lifestyles during the pandemic, the prevalence and crude and adjusted prevalence ratios (RPa) were estimated by Poisson regression. Results: There was a reduction in physical activity (60% without NCDs and 58% with NCDs), vegetable consumption (10.8% in those without NCDs and 12.7% in those with NCDs). On the other hand, there was an increase in the time spent using television and computer/tablet (302% and 43.5% in those with NCDs and 196.5% and 30.6% without NCDs, respectively); consumption of frozen foods (43.6% in those without NCDs and 53.7% without NCDs), snacks (42.3% without NCDs and 31.2% with NCDs) and chocolate (14.8% without NCDs). During the pandemic, NCDs patients showed less practice of sufficient physical activity (RPa 0.77; CI 0.65–0.92), greater habit of watching TV (RPa 1.16; CI 1.08–1.26) and lower consumption of vegetables (RPa 0.88; CI 0.81–0.96). Conclusion: It was evident that adults with NCDs had their lifestyles more altered during the COVID-19 pandemic.Objetivo: Comparar as mudanças de estilos de vida antes e durante a pandemia COVID-19, segundo presença ou não de doenças crônicas não transmissíveis (DCNT) em adultos brasileiros. Métodos: Estudo transversal, com dados da pesquisa ConVid, realizada entre abril e maio de 2020. Avaliaram-se as variáveis: estilo de vida e a presença de uma ou mais DCNT (diabetes, hipertensão, doença respiratória, doença do coração e câncer). As características sociodemográficas foram usadas como ajuste. Calcularam-se as frequências relativas e os intervalos de confiança (IC) de 95% das variáveis antes e durante a pandemia. Para a comparação de grupos, sem ou com DCNT, estimaram-se as prevalências e razões de prevalência bruta e ajustada (RPa) utilizando a regressão de Poisson. Resultados: Houve redução da prática de atividade física (60,0% nos sem DCNT e 58,0% nos com DCNT) e do consumo de hortaliças (10,8% nos sem DCNT e 12,7% nos com DCNT). Verificou-se aumento no tempo de uso de televisão e computador/tablet (302% e 43,5% nos com DCNT e 196,5% e 30,6% sem DCNT, respectivamente); consumo de congelados (43,6% nos sem DCNT e 53,7% com DCNT), salgadinhos (42,3% sem DCNT e 31,2% com DCNT) e chocolate (14,8% sem DCNT). Durante a pandemia, portadores de DCNT apresentaram menor prática de atividade física suficiente (RPa 0,77; IC 0,65–0,92), maior hábito de assistir TV (RPa 1,16; IC 1,08–1,26) e menor consumo de hortaliças (RPa 0,88; IC 0,81–0,96). Conclusão: Evidenciou-se que adultos com DCNT tiveram seus estilos de vida mais alterados durante a pandemia de COVID-19

Global, regional, and national burden of disorders affecting the nervous system, 1990–2021: a systematic analysis for the Global Burden of Disease Study 2021

BackgroundDisorders affecting the nervous system are diverse and include neurodevelopmental disorders, late-life neurodegeneration, and newly emergent conditions, such as cognitive impairment following COVID-19. Previous publications from the Global Burden of Disease, Injuries, and Risk Factor Study estimated the burden of 15 neurological conditions in 2015 and 2016, but these analyses did not include neurodevelopmental disorders, as defined by the International Classification of Diseases (ICD)-11, or a subset of cases of congenital, neonatal, and infectious conditions that cause neurological damage. Here, we estimate nervous system health loss caused by 37 unique conditions and their associated risk factors globally, regionally, and nationally from 1990 to 2021.MethodsWe estimated mortality, prevalence, years lived with disability (YLDs), years of life lost (YLLs), and disability-adjusted life-years (DALYs), with corresponding 95% uncertainty intervals (UIs), by age and sex in 204 countries and territories, from 1990 to 2021. We included morbidity and deaths due to neurological conditions, for which health loss is directly due to damage to the CNS or peripheral nervous system. We also isolated neurological health loss from conditions for which nervous system morbidity is a consequence, but not the primary feature, including a subset of congenital conditions (ie, chromosomal anomalies and congenital birth defects), neonatal conditions (ie, jaundice, preterm birth, and sepsis), infectious diseases (ie, COVID-19, cystic echinococcosis, malaria, syphilis, and Zika virus disease), and diabetic neuropathy. By conducting a sequela-level analysis of the health outcomes for these conditions, only cases where nervous system damage occurred were included, and YLDs were recalculated to isolate the non-fatal burden directly attributable to nervous system health loss. A comorbidity correction was used to calculate total prevalence of all conditions that affect the nervous system combined.FindingsGlobally, the 37 conditions affecting the nervous system were collectively ranked as the leading group cause of DALYs in 2021 (443 million, 95% UI 378–521), affecting 3·40 billion (3·20–3·62) individuals (43·1%, 40·5–45·9 of the global population); global DALY counts attributed to these conditions increased by 18·2% (8·7–26·7) between 1990 and 2021. Age-standardised rates of deaths per 100 000 people attributed to these conditions decreased from 1990 to 2021 by 33·6% (27·6–38·8), and age-standardised rates of DALYs attributed to these conditions decreased by 27·0% (21·5–32·4). Age-standardised prevalence was almost stable, with a change of 1·5% (0·7–2·4). The ten conditions with the highest age-standardised DALYs in 2021 were stroke, neonatal encephalopathy, migraine, Alzheimer's disease and other dementias, diabetic neuropathy, meningitis, epilepsy, neurological complications due to preterm birth, autism spectrum disorder, and nervous system cancer.InterpretationAs the leading cause of overall disease burden in the world, with increasing global DALY counts, effective prevention, treatment, and rehabilitation strategies for disorders affecting the nervous system are needed

Global burden of 288 causes of death and life expectancy decomposition in 204 countries and territories and 811 subnational locations, 1990–2021: a systematic analysis for the Global Burden of Disease Study 2021

BACKGROUND Regular, detailed reporting on population health by underlying cause of death is fundamental for public health decision making. Cause-specific estimates of mortality and the subsequent effects on life expectancy worldwide are valuable metrics to gauge progress in reducing mortality rates. These estimates are particularly important following large-scale mortality spikes, such as the COVID-19 pandemic. When systematically analysed, mortality rates and life expectancy allow comparisons of the consequences of causes of death globally and over time, providing a nuanced understanding of the effect of these causes on global populations. METHODS The Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2021 cause-of-death analysis estimated mortality and years of life lost (YLLs) from 288 causes of death by age-sex-location-year in 204 countries and territories and 811 subnational locations for each year from 1990 until 2021. The analysis used 56 604 data sources, including data from vital registration and verbal autopsy as well as surveys, censuses, surveillance systems, and cancer registries, among others. As with previous GBD rounds, cause-specific death rates for most causes were estimated using the Cause of Death Ensemble model-a modelling tool developed for GBD to assess the out-of-sample predictive validity of different statistical models and covariate permutations and combine those results to produce cause-specific mortality estimates-with alternative strategies adapted to model causes with insufficient data, substantial changes in reporting over the study period, or unusual epidemiology. YLLs were computed as the product of the number of deaths for each cause-age-sex-location-year and the standard life expectancy at each age. As part of the modelling process, uncertainty intervals (UIs) were generated using the 2·5th and 97·5th percentiles from a 1000-draw distribution for each metric. We decomposed life expectancy by cause of death, location, and year to show cause-specific effects on life expectancy from 1990 to 2021. We also used the coefficient of variation and the fraction of population affected by 90% of deaths to highlight concentrations of mortality. Findings are reported in counts and age-standardised rates. Methodological improvements for cause-of-death estimates in GBD 2021 include the expansion of under-5-years age group to include four new age groups, enhanced methods to account for stochastic variation of sparse data, and the inclusion of COVID-19 and other pandemic-related mortality-which includes excess mortality associated with the pandemic, excluding COVID-19, lower respiratory infections, measles, malaria, and pertussis. For this analysis, 199 new country-years of vital registration cause-of-death data, 5 country-years of surveillance data, 21 country-years of verbal autopsy data, and 94 country-years of other data types were added to those used in previous GBD rounds. FINDINGS The leading causes of age-standardised deaths globally were the same in 2019 as they were in 1990; in descending order, these were, ischaemic heart disease, stroke, chronic obstructive pulmonary disease, and lower respiratory infections. In 2021, however, COVID-19 replaced stroke as the second-leading age-standardised cause of death, with 94·0 deaths (95% UI 89·2-100·0) per 100 000 population. The COVID-19 pandemic shifted the rankings of the leading five causes, lowering stroke to the third-leading and chronic obstructive pulmonary disease to the fourth-leading position. In 2021, the highest age-standardised death rates from COVID-19 occurred in sub-Saharan Africa (271·0 deaths [250·1-290·7] per 100 000 population) and Latin America and the Caribbean (195·4 deaths [182·1-211·4] per 100 000 population). The lowest age-standardised death rates from COVID-19 were in the high-income super-region (48·1 deaths [47·4-48·8] per 100 000 population) and southeast Asia, east Asia, and Oceania (23·2 deaths [16·3-37·2] per 100 000 population). Globally, life expectancy steadily improved between 1990 and 2019 for 18 of the 22 investigated causes. Decomposition of global and regional life expectancy showed the positive effect that reductions in deaths from enteric infections, lower respiratory infections, stroke, and neonatal deaths, among others have contributed to improved survival over the study period. However, a net reduction of 1·6 years occurred in global life expectancy between 2019 and 2021, primarily due to increased death rates from COVID-19 and other pandemic-related mortality. Life expectancy was highly variable between super-regions over the study period, with southeast Asia, east Asia, and Oceania gaining 8·3 years (6·7-9·9) overall, while having the smallest reduction in life expectancy due to COVID-19 (0·4 years). The largest reduction in life expectancy due to COVID-19 occurred in Latin America and the Caribbean (3·6 years). Additionally, 53 of the 288 causes of death were highly concentrated in locations with less than 50% of the global population as of 2021, and these causes of death became progressively more concentrated since 1990, when only 44 causes showed this pattern. The concentration phenomenon is discussed heuristically with respect to enteric and lower respiratory infections, malaria, HIV/AIDS, neonatal disorders, tuberculosis, and measles. INTERPRETATION Long-standing gains in life expectancy and reductions in many of the leading causes of death have been disrupted by the COVID-19 pandemic, the adverse effects of which were spread unevenly among populations. Despite the pandemic, there has been continued progress in combatting several notable causes of death, leading to improved global life expectancy over the study period. Each of the seven GBD super-regions showed an overall improvement from 1990 and 2021, obscuring the negative effect in the years of the pandemic. Additionally, our findings regarding regional variation in causes of death driving increases in life expectancy hold clear policy utility. Analyses of shifting mortality trends reveal that several causes, once widespread globally, are now increasingly concentrated geographically. These changes in mortality concentration, alongside further investigation of changing risks, interventions, and relevant policy, present an important opportunity to deepen our understanding of mortality-reduction strategies. Examining patterns in mortality concentration might reveal areas where successful public health interventions have been implemented. Translating these successes to locations where certain causes of death remain entrenched can inform policies that work to improve life expectancy for people everywhere. FUNDING Bill & Melinda Gates Foundation

Phosphate and sulfate influence on arsenic phytotoxicity in Crambe abyssinica Hochst

Um grande esforço é empregado na seleção de espécies para a fitorremediação de áreas contaminadas com arsênio. O comportamento das plantas em relação à presença de arsênio na região da rizosfera pode diferir, entre outros fatores, em função da concentração do metaloide, da presença de outros íons e de fatores intrínsecos da espécie. Por isso, tão importante quanto a seleção de espécies tolerantes ao arsênio é o desenvolvimento de métodos que favoreçam o crescimento de plantas sobre o substrato, otimizando o processo de recuperação de uma área contaminada por esse metalóide. Assim, o objetivo desse estudo foi avaliar o potencial da espécie Crambe abyssinica Hoscht para a utilização em programas de revegetação de áreas contaminadas com arsênio e a fitotoxicidade do arsenato nessas plantas em diferentes concentrações de fosfato e sulfato. Para alcançar esses objetivos foram conduzidos dois experimentos em casa de vegetação. Inicialmente plantas de crambe, cultivadas em solução nutritiva, foram expostas ao arsênio nas concentrações: 0,0; 0;2; 0,4; 0,6; 0,9 e 1,2 mmol L-1; fornecido na forma de arsenato de sódio (Na2HAsO4+7H2O), por duas semanas. Após este período, avaliaram-se a altura e a área foliar das plantas e quantificou-se a matéria seca e a concentração de As, P e S na raiz e na parte aérea. As plantas toleraram o estresse causado pelo As durante todo o período experimental, pois não foi observada a morte das plantas e, além disso, absorveram e armazenaram expressivas quantidades de arsênio, especialmente na raiz, indicando o potencial de uso da espécie Crambe abyssinica como espécie fitoestabilizadora de arsênio. Em outro experimento, plantas de crambe foram cultivadas em meio hidropônico, com solução de Hoagland e Arnon, meia força, durante duas semanas. Após esse período, aplicaram-se os tratamentos, que consistiram em três concentrações de fosfato (0,4; 0,8; 1,2 mmol L-1), sulfato (0,8; 1,6; 2,4 mmol L-1) e arsenato (0,0; 0,3; 0,6 mmol L-1), fornecidos nas formas de ácido fosfórico (H3PO4), ácido sulfúrico (H2SO4) e arsenato de sódio (Na2HAsO4+7H2O), respectivamente, configurando um esquema fatorial 3 x 3 x 3, com três repetições. Duas semanas após a aplicação dos tratamentos aferiram-se as trocas gasosas (taxa fotossintética, condutância estomática, concentração interna de CO 2 e taxa transpiratória), os parâmetros de fluorescência de clorofila α (fluorescência mínima, fluorescência máxima e o rendimento quântico potencial do fotossistema II), a matéria seca e a concentração de As, P e S na raiz e na parte aérea das plantas. De maneira geral, foi observado que concentrações mais elevadas de fosfato amenizaram os efeitos tóxicos de As em plantas de Crambe abyssinica. Por outro lado, em concentrações mais elevadas de sulfato os teores de As nas raízes das plantas foram maiores e, no geral, não contribuíram para a diminuição da toxicidade do As. Para as trocas gasosas, maiores concentrações de fosfato minimizaram o efeito tóxico do arsênio e aumentaram a taxa fotossintética. As doses de arsenato, fosfato e sulfato ultilizadas não afetaram as variáveis relacionadas à clorofila α. Os resultados encontrados indicam que a toxicidade do arsênio em Crambe abyssinica está relacionada, principalmente, a danos no sistema radicular, e que concentrações crescentes de fosfato minimizam os efeitos tóxicos do arsênio nesta espécie.A huge effort has been applied to select species for the phytoremediation of arsenic contaminated areas. Plants behavior with respect to arsenic presence on the rhizosphere region can differ due to the metalloid concentration, the presence of other ions and intrinsic factors of the species. Hence, as important as the selection of arsenic tolerant species, is the development of methods that favor plants growth over the substrate, optimizing the recovery process of the contaminated area. So, the aim of this study was to evaluate the potential use of the species Crambe abyssinica Hoscht in revegetation programs in As contaminated areas and the arsenate phytotoxicity under different contents of phosphate and sulphate. To achieve this aim two experiments were conducted in greenhouse. Firstly, crambe plants, grown in nutrient solution, were exposed to arsenic under different concentrations: 0,00; 0,2; 0,4; 0,6; 0,9 and 1,2 mmol L -1, provided as sodium arsenate (Na2HAsO4+7H2O), for two weeks. After this period, it was evaluated the height and the leaf area and it was quantified the dry matter and the contents of As, P and S in the root and in the aerial part. The plants tolerated the stress caused by As during the entire experimental period, since no plant death was observed. Besides that, the plants absorbed and stored large quantities of As, especially on the root, what indicates the potential use of the species Crambe abyssinica in recovery programs of As contaminated areas. In the second experiment, crambe plants were grown in hydroponic solution with half strength, during two weeks. Thereafter, it was added the treatments, that consisted of three concentrations of phosphate (0,4; 0,8; 1,2 mmol L-1), sulphate (0,8; 1,6; 2,4 mmol L-1) and arsenate, provided as phosphoric acid (H3PO4), sulfuric acid (H2SO4) and sodium arsenate (Na2HAsO4+7H2O), respectively. It was adopted the 3 x 3 x 3 factorial, with three trials. Two weeks after the treatments addition, it was gauged the gas exchanges (photosynthetic rate, stomatal conductance, internal CO2 concentration and transpiration rate), α chlorophyll fluorescence parameters (minimum fluorescence, maximum fluorescence and the potential quantum yield of photosystem II), dry matter and the contents of As, P e S in the root and in the aerial part. In general, it was observed that higher concentrations of phosphate softened the As toxic effects in Crambe abyssinica plants. On the other hand, higher concentrations of sulphate increased As contents in the roots and, in general, did not contributed to decrease the As toxicity. In gas exchanges, higher concentrations of phosphate decreased the toxic effect of As and increased the photosynthetic rate. The arsenate, phosphate and sulphate doses did not affected the variables related to α chlorophyll. The results indicate that As toxicity in Crambe abyssinica is related, mainly, to damage to the root system, and that increasing concentrations of phosphate minimize the toxic effects of arsenic in this species.Conselho Nacional de Desenvolvimento Científico e Tecnológic

Arsenic toxicity in Acacia mangium willd. and mimosa Caesalpiniaefolia benth. seedlings

Acacia mangium and Mimosa caesalpiniaefolia are fast-growing woody fabaceous species that might be suitable for phytoremediation of arsenic (As)-contaminated sites. To date, few studies on their tolerance to As toxicity have been published. Therefore, this study assessed As toxicity symptoms in A. mangium and M. caesalpiniaefolia seedlings under As stress in a greenhouse. Seedlings of Acacia mangium and M. caesalpiniaefolia were grown for 120 d in an Oxisol-sand mixture with 0, 50, 100, 200, and 400 mg kg-1 As, in four replications in four randomized blocks. The plants were assessed for visible toxicity symptoms, dry matter production, shoot/root ratio, root anatomy and As uptake. Analyses of variance and regression showed that the growth of A. mangium and M. caesalpiniaefolia was severely hindered by As, with a reduction in dry matter production of more than 80 % at the highest As rate. The root/shoot ratio increased with increasing As rates. At a rate of 400 mg kg-1 As, whitish chlorosis appeared on Mimosa caesalpiniaefolia seedlings. The root anatomy of both species was altered, resulting in cell collapse, death of root buds and accumulation of phenolic compounds. Arsenic concentration was several times greater in roots than in shoots, with more than 150 and 350 mg kg-1 in M. caesalpiniaefolia and A. mangium roots, respectively. These species could be suitable for phytostabilization of As-contaminated sites, but growth-stimulating measures should be used

Neotropical freshwater fisheries : A dataset of occurrence and abundance of freshwater fishes in the Neotropics

The Neotropical region hosts 4225 freshwater fish species, ranking first among the world's most diverse regions for freshwater fishes. Our NEOTROPICAL FRESHWATER FISHES data set is the first to produce a large-scale Neotropical freshwater fish inventory, covering the entire Neotropical region from Mexico and the Caribbean in the north to the southern limits in Argentina, Paraguay, Chile, and Uruguay. We compiled 185,787 distribution records, with unique georeferenced coordinates, for the 4225 species, represented by occurrence and abundance data. The number of species for the most numerous orders are as follows: Characiformes (1289), Siluriformes (1384), Cichliformes (354), Cyprinodontiformes (245), and Gymnotiformes (135). The most recorded species was the characid Astyanax fasciatus (4696 records). We registered 116,802 distribution records for native species, compared to 1802 distribution records for nonnative species. The main aim of the NEOTROPICAL FRESHWATER FISHES data set was to make these occurrence and abundance data accessible for international researchers to develop ecological and macroecological studies, from local to regional scales, with focal fish species, families, or orders. We anticipate that the NEOTROPICAL FRESHWATER FISHES data set will be valuable for studies on a wide range of ecological processes, such as trophic cascades, fishery pressure, the effects of habitat loss and fragmentation, and the impacts of species invasion and climate change. There are no copyright restrictions on the data, and please cite this data paper when using the data in publications

Global burden of 288 causes of death and life expectancy decomposition in 204 countries and territories and 811 subnational locations, 1990–2021: a systematic analysis for the Global Burden of Disease Study 2021

BackgroundRegular, detailed reporting on population health by underlying cause of death is fundamental for public health decision making. Cause-specific estimates of mortality and the subsequent effects on life expectancy worldwide are valuable metrics to gauge progress in reducing mortality rates. These estimates are particularly important following large-scale mortality spikes, such as the COVID-19 pandemic. When systematically analysed, mortality rates and life expectancy allow comparisons of the consequences of causes of death globally and over time, providing a nuanced understanding of the effect of these causes on global populations.MethodsThe Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2021 cause-of-death analysis estimated mortality and years of life lost (YLLs) from 288 causes of death by age-sex-location-year in 204 countries and territories and 811 subnational locations for each year from 1990 until 2021. The analysis used 56 604 data sources, including data from vital registration and verbal autopsy as well as surveys, censuses, surveillance systems, and cancer registries, among others. As with previous GBD rounds, cause-specific death rates for most causes were estimated using the Cause of Death Ensemble model—a modelling tool developed for GBD to assess the out-of-sample predictive validity of different statistical models and covariate permutations and combine those results to produce cause-specific mortality estimates—with alternative strategies adapted to model causes with insufficient data, substantial changes in reporting over the study period, or unusual epidemiology. YLLs were computed as the product of the number of deaths for each cause-age-sex-location-year and the standard life expectancy at each age. As part of the modelling process, uncertainty intervals (UIs) were generated using the 2·5th and 97·5th percentiles from a 1000-draw distribution for each metric. We decomposed life expectancy by cause of death, location, and year to show cause-specific effects on life expectancy from 1990 to 2021. We also used the coefficient of variation and the fraction of population affected by 90% of deaths to highlight concentrations of mortality. Findings are reported in counts and age-standardised rates. Methodological improvements for cause-of-death estimates in GBD 2021 include the expansion of under-5-years age group to include four new age groups, enhanced methods to account for stochastic variation of sparse data, and the inclusion of COVID-19 and other pandemic-related mortality—which includes excess mortality associated with the pandemic, excluding COVID-19, lower respiratory infections, measles, malaria, and pertussis. For this analysis, 199 new country-years of vital registration cause-of-death data, 5 country-years of surveillance data, 21 country-years of verbal autopsy data, and 94 country-years of other data types were added to those used in previous GBD rounds.FindingsThe leading causes of age-standardised deaths globally were the same in 2019 as they were in 1990; in descending order, these were, ischaemic heart disease, stroke, chronic obstructive pulmonary disease, and lower respiratory infections. In 2021, however, COVID-19 replaced stroke as the second-leading age-standardised cause of death, with 94·0 deaths (95% UI 89·2–100·0) per 100 000 population. The COVID-19 pandemic shifted the rankings of the leading five causes, lowering stroke to the third-leading and chronic obstructive pulmonary disease to the fourth-leading position. In 2021, the highest age-standardised death rates from COVID-19 occurred in sub-Saharan Africa (271·0 deaths [250·1–290·7] per 100 000 population) and Latin America and the Caribbean (195·4 deaths [182·1–211·4] per 100 000 population). The lowest age-standardised death rates from COVID-19 were in the high-income super-region (48·1 deaths [47·4–48·8] per 100 000 population) and southeast Asia, east Asia, and Oceania (23·2 deaths [16·3–37·2] per 100 000 population). Globally, life expectancy steadily improved between 1990 and 2019 for 18 of the 22 investigated causes. Decomposition of global and regional life expectancy showed the positive effect that reductions in deaths from enteric infections, lower respiratory infections, stroke, and neonatal deaths, among others have contributed to improved survival over the study period. However, a net reduction of 1·6 years occurred in global life expectancy between 2019 and 2021, primarily due to increased death rates from COVID-19 and other pandemic-related mortality. Life expectancy was highly variable between super-regions over the study period, with southeast Asia, east Asia, and Oceania gaining 8·3 years (6·7–9·9) overall, while having the smallest reduction in life expectancy due to COVID-19 (0·4 years). The largest reduction in life expectancy due to COVID-19 occurred in Latin America and the Caribbean (3·6 years). Additionally, 53 of the 288 causes of death were highly concentrated in locations with less than 50% of the global population as of 2021, and these causes of death became progressively more concentrated since 1990, when only 44 causes showed this pattern. The concentration phenomenon is discussed heuristically with respect to enteric and lower respiratory infections, malaria, HIV/AIDS, neonatal disorders, tuberculosis, and measles.InterpretationLong-standing gains in life expectancy and reductions in many of the leading causes of death have been disrupted by the COVID-19 pandemic, the adverse effects of which were spread unevenly among populations. Despite the pandemic, there has been continued progress in combatting several notable causes of death, leading to improved global life expectancy over the study period. Each of the seven GBD super-regions showed an overall improvement from 1990 and 2021, obscuring the negative effect in the years of the pandemic. Additionally, our findings regarding regional variation in causes of death driving increases in life expectancy hold clear policy utility. Analyses of shifting mortality trends reveal that several causes, once widespread globally, are now increasingly concentrated geographically. These changes in mortality concentration, alongside further investigation of changing risks, interventions, and relevant policy, present an important opportunity to deepen our understanding of mortality-reduction strategies. Examining patterns in mortality concentration might reveal areas where successful public health interventions have been implemented. Translating these successes to locations where certain causes of death remain entrenched can inform policies that work to improve life expectancy for people everywhere