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

Air pollution tolerance, anticipated performance, and metal accumulation indices of four evergreen tree species in Dhaka, Bangladesh

Trees in urban forests are able to better air quality by removing particulate matter (PM) from the atmosphere through the accumulation of particles on their leaf surfaces. When exposed to air pollutants, the physiology, morphology, and biochemistry of a plant may be affected, which will result in alterations to that plant’s function and growth. In this study, we assessed, for the first time, the tolerance or sensitivity of four evergreen trees (Ficus benghalensis, Ficus religiosa, Mangifera indica, and Polyalthia longifolia) towards air pollution by employing several indices. The trees, which are commonly grown along the roadside in Dhaka, Bangladesh, were evaluated by using the air pollution tolerance index (APTI), the anticipated performance index (API), and the metal accumulation index (MAI). The deposition of four heavy metals (Cd, Cr, Pb, and Ni) on the leaves of four aforementioned tree species was studied employing ICP-MS, and subsequently, a predictive foliar MAI was created. APTI values of the studied plants varied from 10.31 to 12.51 implying that they were either intermediately tolerant or sensitive. A significantly strong positive correlation was obtained between APTI and relative water content (RWC) (r = 0.864; p < 0.001) and between APTI and ascorbic acid content (AAC) (r = 0.748; p < 0.01). The API revealed M. indica as a good performer, which maintained the highest score (68.75%) among the tree species irrespective of different sites. The Pb concentrations were anomalously high in the atmosphere of Dhaka, suggesting its anthropogenic origin. A significant (r = 0.722; p < 0.01) relationship was found between Cd and Pb indicating their common origin. Among the species, F. benghalensis had the highest MAI value (13.60). The MAI value was found to have a significant association with pH, AAC, and total chlorophyll content. Based on APTI, API, and MAI values, the most suitable plant species for urban forest development was identified to be M. indica followed by F. benghalensis and F. religiosa

Vitamin D supplementation among Bangladeshi children under-five years of age hospitalised for severe pneumonia: A randomised placebo controlled trial.

IntroductionVitamin D is important for its immunomodulatory role and there is an independent association between vitamin D deficiency and pneumonia. We assessed the effect of vitamin D supplementation on the outcome in children hospitalized for severe pneumonia.MethodsThis was a randomised, double blinded, placebo-controlled clinical trial in children aged >2-59 months with severe pneumonia attending Dhaka Hospital, icddr,b. Children received age-specific megadose of vitamin D3 (20,000IU: FindingsWe enrolled 100 children in placebo group and 97 in vitamin D group. On admission, 50 (52%) and 49 (49%) of children in vitamin D and placebo groups, respectively were vitamin D deficient. Among children with a sufficient serum vitamin D level on admission, a lower trend for duration of resolution of severe pneumonia in hours [72(IQR:44-96)vs. 88(IQR:48-132);p = 0.07] and duration of hospital stay in days [4(IQR:3-5)vs.5(IQR:4-7);P = 0.09] was observed in vitamin D group compared to placebo. No beneficial effect was observed in vitamin D deficient group or irrespective of vitamin D status.ConclusionAge-specific mega dose of vitamin D followed by a maintenance dose shown to have no statistical difference between the two intervention groups, however there was a trend of reduction of time to recovery from pneumonia and overall duration of hospital stay in under-five children with a sufficient serum vitamin D level on hospital admission

Vitamin D Supplementation among Bangladeshi Children under-Five Years of Age Hospitalised for Severe Pneumonia: A Randomised Placebo Controlled Trial

INTRODUCTION: Vitamin D is important for its immunomodulatory role and there is an independent association between vitamin D deficiency and pneumonia. We assessed the effect of vitamin D supplementation on the outcome in children hospitalized for severe pneumonia. METHODS: This was a randomised, double blinded, placebo-controlled clinical trial in children aged \u3e2–59 months with severe pneumonia attending Dhaka Hospital, icddr,b. Children received age-specific megadose of vitamin D3 (20,000IU: \u3c 6 months, 50,000 IU: 6–12 months, 100,000 IU:13–59 months) or placebo on first day and 10,000 IU as maintenance dose for next 4 days or until discharge (if discharged earlier) along with standard therapy. This trial is registered at ClinicalTrials.gov, number NCT02185196. FINDINGS: We enrolled 100 children in placebo group and 97 in vitamin D group. On admission, 50 (52%) and 49 (49%) of children in vitamin D and placebo groups, respectively were vitamin D deficient. Among children with a sufficient serum vitamin D level on admission, a lower trend for duration of resolution of severe pneumonia in hours [72(IQR:44-96)vs. 88(IQR:48-132);p = 0.07] and duration of hospital stay in days [4(IQR:3-5)vs.5(IQR:4-7);P = 0.09] was observed in vitamin D group compared to placebo. No beneficial effect was observed in vitamin D deficient group or irrespective of vitamin D status. CONCLUSION: Age-specific mega dose of vitamin D followed by a maintenance dose shown to have no statistical difference between the two intervention groups, however there was a trend of reduction of time to recovery from pneumonia and overall duration of hospital stay in under-five children with a sufficient serum vitamin D level on hospital admission