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

Phase−amplitude coupling between theta and gamma oscillations adapts to speech rate

First published: 24 April 2019Low- and high-frequency cortical oscillations play an important role in speech processing. Low-frequency neural oscillations in the delta (<4Hz) and theta (4–8 Hz) bands entrain to the prosodic and syllabic rates of speech, respectively. Theta band neural oscillations modulate high-frequency neural oscillations in the gamma band (28−40Hz), which have been hypothesized to be crucial for processing phonemes in natural speech. Since speech rate is known to vary considerably, both between and within talkers, it has yet to be determined whether this nested gamma response reflects an externally induced rhythm sensitive to the rate of the fine-grained structure of the input or a speech rate−independent endogenous response. Here, we recorded magnetoencephalography responses from participants listening to a speech delivered at different rates: decelerated, normal, and accelerated. We found that the phase of theta band oscillations in left and right auditory regions adjusts to speech rate variations. Importantly, we showed that the peak of the gamma response—coupled to the phase of theta—follows the speech rate. This indicates that gamma activity in auditory regions synchronizes with the fine-grain properties of speech, possibly reflecting detailed acoustic analysis of the input.This research was supported in part by the Agence Nationale de la Recherche (ANR-10-LABX-0087 IEC and ANR- 10-IDEX-0001-02 PSL), the EUR Frontiers (ANR- 17-EURE-0017), the European Research Council (ERC-2011-ADG-295362), and the MINECO (PSI2015-67353-R). This work was also partially supported by the Agencia Estatal de Investigación (AEI), the Fondo Europeo de Desarrollo Regional (FEDER) (grant PSI2015-65694-P), the “Severo Ochoa” programme (SEV-2015-490) for Centres of Excellence in R&D, and the Basque government (grant PI_2016_1_0014). The authors would like to acknowledge all the participants taking part in this study

Liverworts of Alagoas State, Brazil

A list of liverworts from Alagoas State was compiled and is presented here. The list is based on catalogues and previous papers as well as the results of an unpublished survey carried out at the Murici Ecological Station (EsEc), an important protected area of the Brazilian Northeast (9º11'05" - 9º16'48"S; 35º45'20" - 35º55'12"W). One-hundred and sixteen liverworts have been recorded for the state of Alagoas, of which 106 occur at EsEc Murici. Seventy-eight are new occurrences for Alagoas, and seven of these are also new occurrences for northeastern Brazil. Data on geographic distribution in Brazil and worldwide is given here, in addition to ecological and taxonomic comments on the species that are new occurrences for the Northeast region

A importância de Reservas Particulares do Patrimônio Natural para a conservação da brioflora da Mata Atlântica: um estudo em El Nagual, Magé, RJ, Brasil The importance of Private Natural Heritage Reserves for conservation of Atlantic rain forest bryoflora: a study at El Nagual, Magé, Rio de Janeiro State, Brazil

Foi realizado o levantamento das briófitas da RPPN El Nagual, uma área de floresta submontana no Estado do Rio de Janeiro. Foram registradas 137 espécies (um antócero, 70 hepáticas e 66 musgos) e duas variedades, distribuídas em 75 gêneros e 37 famílias, sendo cinco novas ocorrências para o estado. Lejeuneaceae (27 spp.), Pilotrichaceae (17 spp.), Aneuraceae (9 spp.) e Calymperaceae (8 spp.) destacam-se pela riqueza de espécies (44% da brioflora). Sete formas de vida foram caracterizadas, predominando trama (37%), tufo (16%) e talosa (15%). Seis tipos de substrato são colonizados na área, predominando espécies corticícolas (52%) e rupícolas (42%). Em relação aos padrões de distribuição, predominaram espécies neotropicais e pantropicais. Foram encontradas quatro espécies caracterizadas como vulneráveis no estado. Os resultados demonstram que a brioflora da RPPN é rica e evidenciam a importância dessa categoria de unidade de conservação na proteção de remanescentes de Mata Atlântica e conservação da brioflora.<br>A floristic survey of the bryophytes was carried out in the El Nagual Private Natural Heritage Reserve, a submontane Atlantic rain forest remnant in Rio de Janeiro state. One hundred and thirty seven species were recorded (one Anthocerotae, 70 hepatics and 66 mosses) plus two varieties, in 75 genera and 37 families. Five species are new records for Rio de Janeiro state. Lejeuneaceae (27 spp.), Pilotrichaceae (17 spp.), Aneuraceae (9 spp.), and Calymperaceae (8 spp.) are especially rich in species (44% of the bryoflora). Seven life-forms were found; the most common are weft (37%), turf (16%), and thallose (15%). Six kinds of substrate were colonized, the most important species types being corticicolous (52%) and rupicolous (42%). The most common distribution patterns were Neotropical and Pantropical. Four species were considered to be vulnerable in the state. The results show that the bryoflora of the El Nagual Reserve is relatively rich and demonstrate the importance of this conservation unit category in the protection of remnant Atlantic rain forests and in the conservation of the bryoflora