Computerized and Non-Computerized Colour Vision Tests

Introduction: Measuring colour discrimination of people who carry out tasks where colour is used to convey information and accurate colour judgments are essential for safe and efficient performance of the task is important in order to ensure that they can carry out the tasks. Individuals with congenital colour vision deficiencies are at a greater risk in making an error in colour judgment and this is the primary reason for colour vision testing in industry. Today, there are a large number of colour vision tests to detect colour vision deficiencies and/or estimate one’s ability to discriminate colours. Purpose: The purpose of this study is to determine the validity and repeatability of new colour vision test “Colour Vision Reaction Time” (CVRT) for screening for colour vision defect. The study will also determine the repeatability of a selection of clinical colour vision tests, which are currently in use. Material and methods: The test series was administrated to 75 colour normal subjects and 47 participants with red-green defects. Colour vision was classified based on Nagel anomaloscope. In the pseudoisochromatic tests, the Hardy, Rand, Rittler 4th edition (HRR), Ishihara 38 plate edition and Pseudoisochromatic Plates Ishihara Compatible (PIPC) tests subjects are required to identify coloured figure within background of a different colour. For the Colour Vision Reaction Time (CVRT) test, subjects need to locate a coloured Square on a computer’s screen using a mouse. The Cone Contrast Sensitivity Test (CCST) requires individuals to identify coloured letters that may appear in a gray background on the computer’s screen. A prototype of the ColorDx (pColorDx) test is similar to the printed pseudoisochromatic plates except that the plates are displayed on a computer screen. The Farnsworth-Munsell D15 (D15) test requires subjects to arrange coloured caps in order according to colour starting from a fixed cap. Results: The agreement of the printed pseudoisochromatic tests with anomaloscope in terms of screening for red-green defect was good with kappa (κ) coefficient of agreement value of 0.96 or more on all three tests. The repeatability of the three tests was good with κ coefficient of 0.96 or more on the three tests. Both HRR and PIPC tests can screen for blue-yellow defects. There were 2 deuteranomalous subjects at the first visit and a different deuteranomalous individual at the second visit who made a single blue-yellow error in the HRR test. In the PIPC test, only one deuteranomalous subject failed the blue-yellow screening plates at the first visit with two errors. In terms of the classification as either protan or deutan, the agreement with the Nagel anomaloscope was perfect with the HRR test and acceptable with the Ishihara, but only fair for the PIPC test. The agreement of the repeatability of the classification was perfect at the HRR test and good at the Ishihara test whereas it was reasonable at the PIPC test. The HRR test was designed to classify the severity of the defect and there was a reasonable correlation between the HRR severity and the Nagel anomaloscope matching ranges. The agreement of the three computerized colour vision tests with anomaloscope was good with κ coefficients ≥0.91. The repeatability of these three tests was good with κ coefficients ≥0.98. All the three tests can screen for blue-yellow defects. In the CVRT test, the response times of most subjects to the blue-yellow test figures were within 1.0 standard deviation of the white control value. The single exception was deuteranomalous subject who did not fail any other blue-yellow screening test. Ten subjects failed the pColorDx blue-yellow test, whereas 3 subjects failed the CCST S-cone portion. The CCST and pColorDx computer test can classify the defect as protan or deutan. Both tests showed a good-to-perfect agreement with anomaloscope. The pColorDx test can grade the severity of the defect in terms of mild, moderate to severe. The Spearman rank correlation coefficient with the Nagel matching ranges was only moderate. The Farnsworth D15 test was included to determine whether there was a difference in the pass rate using the results from the first trial or requiring the subjects to pass on 2 of 3 trials. There was a marginal improvement in the pass rate using the 2 out of 3 rule. The repeatability of the 2 out of 3 trails in the D 15 test showed that there was a good agreement between sessions with κ coefficient of 0.87. In terms of classifying the defect as protan or deutan, based on the visual inspection, there was a good agreement with κ coefficient = 0.83. However, based on the Colour Difference Vector (CDV) angle parameter, all the colour defective subjects was correctly classified. The repeatability of classifying the type of the defect based on the CDV showed perfect agreement between the first and second visit. The D15 can classify the defect as mild versus moderate-to-severe. As expected, the majority of individuals who failed the D15 were classified as having moderate to severe classification on the HRR and pColorDx tests. Discussion and Conclusion: The current study confirms that the three pseudoisochromatic tests are effective in screening for red-green colour vision defect. The HRR test may be preferred over the Ishihara and PIPC because the sensitivity was marginally higher than the other two tests. Agreement of the diagnostic plates with the Nagel anomaloscope as to whether the colour vision defect was protan or deutan varied across tests. The results from this study agreed with the Birch’s (1997) results for the Ishihara in that approximately 85% of the colour defectives were classified correctly as either protan or deutan. However, HRR classification results were slightly better than Cole, et al’s. In terms of the severity, our results were similar to Cole et al in that there were a reasonable correlation between the HRR severity and the Nagel anomaloscope matching ranges. The three computerized colour vision tests are effective in terms of screening for red-green defects. The CCST had the highest agreement with anomaloscope, but it was not significantly different from the other two tests. However, the pColorDx ability to grade the severity was moderate, but it was slightly lower than the HRR plates. All three tests are capable of screening tritan defects. Our results suggest that a small number of deutans are likely to fail this portion of these tests. The D 15 test showed a reasonable repeatability on terms of pass/fail when we used 2 out of 3 rule and marginally better than performing only one trail on separate days. In terms of the repeatability of classification, the study showed that there was a good agreement between sessions based on the visual inspection and perfect agreement between sessions based on Colour Difference Vector parameters

Assessment of Current and Next Generation of Colour Vision Tests for Occupational Use

Introduction: Individuals with congenital colour vision deficiencies are at a greater risk of making an error in colour judgment. Computerized colour vision tests are now available to screen for colour vision defects and quantify the severity of their defect. Purposes: The first experiment compared chromatic thresholds measured on different computerized colour vision tests for colour-normals (CVN) and colour vision defective (CVD) using a common scale. The next experiment evaluated whether dichromatic transformations of the Farnsworth D15 (F-D15) and the ColorDx D15 colors could predict the actual arrangements. The third study evaluated the within-session and between visits repeatability of each of the D15 tests. The last studies determined which one of the newer computer-based tests would replace the Holmes-Wright Type A Lantern (HWA), F-D15 and the CN Lantern. Lastly, the results of a short survey of how a colour vision deficiency affected their lives are presented. Methods: Sixty CVN subjects and 68 CVDs were tested with the Oculus HMC anomaloscope, Psuedoisochromatic tests (the Ishihara, Hardy, Rand, Rittler (4th ed), ColorDx PIP), computrized tests (CAD, Rabin Cone Contrast Test (RCCT), Cambridge Colour Vision Test (CCT), Landolt C Cone Contrast (LandC)), Lantern tests (HWA, CN Lantern), and arrangment tests (F-D15, ColorDx D15). Results: Discrimination ellipses measured in the CIE colour space with the CAD were significantly larger than the ellipse areas measured by CCT for CVNs, protans and deutans. For the tests that measure vector length, there were significant interactions between the three tests and the different subject groups. In general, the dichromatic transformation of the D15 tests provided reasonable predictions of the actual dichromatic arrangements. Both D15 tests studied showed that each test was highly repeatable within and between sessions. As expected, the ColorDx D15 had the highest level of agreement with the F-15, although it was not as challenging as the F-15. The LandC and CAD had significantly higher levels of agreement with the HWA compared with the other tests. Nearly all the CVD failed the CN Lantern test at 4.6m, but the number of errors decreased and the pass rate increased as the viewing distances of the CN lantern was shortened. At the 2.3 m distance, the agreement values for the HRR, ColorDx, and CAD were similar and considered as good. These agreement values decreased as the viewing distance decreased further. The results of the survey study showed that the percentage of dichromats who reported difficulties with colours was more than double of the percentage of anomalous trichromats, but lower than reported by other surveys. Conclusions: The difference between the CAD and CCT colour discrimination ellipses was likely a result of the different number and spacing of the chromatic vectors that were sampled in each program. The differences between the three tests that measured the vector length could be due to the luminance masking noise, monitor artifacts, different angular sizes, and psychophysiological procedures. The RCCT and LandC tests did not show a potential ceiling effect in estimating CVD thresholds, however, the LandC was preferred over the RCCT because it can measure chromatic threshold for CVN. The dichromatic predictions of the D15 tests suggest that this model may be useful in predicting the performance of dichromats on other colour-related tasks. The decrease in errors on the CN Lantern was likely due to the increase in brightness of the test lights with decreasing test distance. Although everyone with a colour vision defect will likely to fail the CN Lantern at 4.6 m, individuals who fail either version of the D15 will almost certainly fail the CN Lantern at 4.6 and 2.3m. A mild classification on the HRR and ColorDx PIP provides a reasonable prediction of who will pass the CN lantern at the shorter distances

Visual resolution under photopic and mesopic conditions in patients with Sjögren's syndrome

AIM: To focus on different visual resolution tasks under photopic and mesopic conditions in Sjögren's syndrome patients compared to age-matched healthy controls. METHODS: The visual resolution measurements included high and low visual acuities and contrast sensitivity functions. These tests were conducted under photopic and then mesopic conditions. Twenty-one Sjögren's syndrome patients and 21 aged-matched healthy volunteers completed all the measurements in this study. RESULTS: Sjögren's syndrome patients have greater impairment in contrast sensitivity than standardized visual acuity. This reduction was significant under the mesopic condition. Also, Sjögren's syndrome patients treated with pilocarpine suffer more than patients without pilocarpine treatment under low light conditions. CONCLUSION: Sjögren's syndrome patients shows greater impairment in different visual resolution tasks due to dry eye symptoms

Global mortality associated with 33 bacterial pathogens in 2019: a systematic analysis for the Global Burden of Disease Study 2019

Background: Reducing the burden of death due to infection is an urgent global public health priority. Previous studies have estimated the number of deaths associated with drug-resistant infections and sepsis and found that infections remain a leading cause of death globally. Understanding the global burden of common bacterial pathogens (both susceptible and resistant to antimicrobials) is essential to identify the greatest threats to public health. To our knowledge, this is the first study to present global comprehensive estimates of deaths associated with 33 bacterial pathogens across 11 major infectious syndromes. Methods: We estimated deaths associated with 33 bacterial genera or species across 11 infectious syndromes in 2019 using methods from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019, in addition to a subset of the input data described in the Global Burden of Antimicrobial Resistance 2019 study. This study included 343 million individual records or isolates covering 11 361 study-location-years. We used three modelling steps to estimate the number of deaths associated with each pathogen: deaths in which infection had a role, the fraction of deaths due to infection that are attributable to a given infectious syndrome, and the fraction of deaths due to an infectious syndrome that are attributable to a given pathogen. Estimates were produced for all ages and for males and females across 204 countries and territories in 2019. 95% uncertainty intervals (UIs) were calculated for final estimates of deaths and infections associated with the 33 bacterial pathogens following standard GBD methods by taking the 2·5th and 97·5th percentiles across 1000 posterior draws for each quantity of interest. Findings: From an estimated 13·7 million (95% UI 10·9–17·1) infection-related deaths in 2019, there were 7·7 million deaths (5·7–10·2) associated with the 33 bacterial pathogens (both resistant and susceptible to antimicrobials) across the 11 infectious syndromes estimated in this study. We estimated deaths associated with the 33 bacterial pathogens to comprise 13·6% (10·2–18·1) of all global deaths and 56·2% (52·1–60·1) of all sepsis-related deaths in 2019. Five leading pathogens—Staphylococcus aureus, Escherichia coli, Streptococcus pneumoniae, Klebsiella pneumoniae, and Pseudomonas aeruginosa—were responsible for 54·9% (52·9–56·9) of deaths among the investigated bacteria. The deadliest infectious syndromes and pathogens varied by location and age. The age-standardised mortality rate associated with these bacterial pathogens was highest in the sub-Saharan Africa super-region, with 230 deaths (185–285) per 100 000 population, and lowest in the high-income super-region, with 52·2 deaths (37·4–71·5) per 100 000 population. S aureus was the leading bacterial cause of death in 135 countries and was also associated with the most deaths in individuals older than 15 years, globally. Among children younger than 5 years, S pneumoniae was the pathogen associated with the most deaths. In 2019, more than 6 million deaths occurred as a result of three bacterial infectious syndromes, with lower respiratory infections and bloodstream infections each causing more than 2 million deaths and peritoneal and intra-abdominal infections causing more than 1 million deaths. Interpretation: The 33 bacterial pathogens that we investigated in this study are a substantial source of health loss globally, with considerable variation in their distribution across infectious syndromes and locations. Compared with GBD Level 3 underlying causes of death, deaths associated with these bacteria would rank as the second leading cause of death globally in 2019; hence, they should be considered an urgent priority for intervention within the global health community. Strategies to address the burden of bacterial infections include infection prevention, optimised use of antibiotics, improved capacity for microbiological analysis, vaccine development, and improved and more pervasive use of available vaccines. These estimates can be used to help set priorities for vaccine need, demand, and development. Funding: Bill & Melinda Gates Foundation, Wellcome Trust, and Department of Health and Social Care, using UK aid funding managed by the Fleming Fund

Global, regional, and national burden of meningitis and its aetiologies, 1990–2019: a systematic analysis for the Global Burden of Disease Study 2019

Background: Although meningitis is largely preventable, it still causes hundreds of thousands of deaths globally each year. WHO set ambitious goals to reduce meningitis cases by 2030, and assessing trends in the global meningitis burden can help track progress and identify gaps in achieving these goals. Using data from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019, we aimed to assess incident cases and deaths due to acute infectious meningitis by aetiology and age from 1990 to 2019, for 204 countries and territories. Methods: We modelled meningitis mortality using vital registration, verbal autopsy, sample-based vital registration, and mortality surveillance data. Meningitis morbidity was modelled with a Bayesian compartmental model, using data from the published literature identified by a systematic review, as well as surveillance data, inpatient hospital admissions, health insurance claims, and cause-specific meningitis mortality estimates. For aetiology estimation, data from multiple causes of death, vital registration, hospital discharge, microbial laboratory, and literature studies were analysed by use of a network analysis model to estimate the proportion of meningitis deaths and cases attributable to the following aetiologies: Neisseria meningitidis, Streptococcus pneumoniae, Haemophilus influenzae, group B Streptococcus, Escherichia coli, Klebsiella pneumoniae, Listeria monocytogenes, Staphylococcus aureus, viruses, and a residual other pathogen category. Findings: In 2019, there were an estimated 236 000 deaths (95% uncertainty interval [UI] 204 000–277 000) and 2·51 million (2·11–2·99) incident cases due to meningitis globally. The burden was greatest in children younger than 5 years, with 112 000 deaths (87 400–145 000) and 1·28 million incident cases (0·947–1·71) in 2019. Age-standardised mortality rates decreased from 7·5 (6·6–8·4) per 100 000 population in 1990 to 3·3 (2·8–3·9) per 100 000 population in 2019. The highest proportion of total all-age meningitis deaths in 2019 was attributable to S pneumoniae (18·1% [17·1–19·2]), followed by N meningitidis (13·6% [12·7–14·4]) and K pneumoniae (12·2% [10·2–14·3]). Between 1990 and 2019, H influenzae showed the largest reduction in the number of deaths among children younger than 5 years (76·5% [69·5–81·8]), followed by N meningitidis (72·3% [64·4–78·5]) and viruses (58·2% [47·1–67·3]). Interpretation: Substantial progress has been made in reducing meningitis mortality over the past three decades. However, more meningitis-related deaths might be prevented by quickly scaling up immunisation and expanding access to health services. Further reduction in the global meningitis burden should be possible through low-cost multivalent vaccines, increased access to accurate and rapid diagnostic assays, enhanced surveillance, and early treatment. Funding: Bill & Melinda Gates Foundation

Global, regional, and national sex-specific burden and control of the HIV epidemic, 1990–2019, for 204 countries and territories : the Global Burden of Diseases Study 2019

Background: The sustainable development goals (SDGs) aim to end HIV/AIDS as a public health threat by 2030. Understanding the current state of the HIV epidemic and its change over time is essential to this effort. This study assesses the current sex-specific HIV burden in 204 countries and territories and measures progress in the control of the epidemic. Methods: To estimate age-specific and sex-specific trends in 48 of 204 countries, we extended the Estimation and Projection Package Age-Sex Model to also implement the spectrum paediatric model. We used this model in cases where age and sex specific HIV-seroprevalence surveys and antenatal care-clinic sentinel surveillance data were available. For the remaining 156 of 204 locations, we developed a cohort-incidence bias adjustment to derive incidence as a function of cause-of-death data from vital registration systems. The incidence was input to a custom Spectrum model. To assess progress, we measured the percentage change in incident cases and deaths between 2010 and 2019 (threshold >75% decline), the ratio of incident cases to number of people living with HIV (incidence-to-prevalence ratio threshold <0·03), and the ratio of incident cases to deaths (incidence-to-mortality ratio threshold <1·0). Findings: In 2019, there were 36·8 million (95% uncertainty interval [UI] 35·1–38·9) people living with HIV worldwide. There were 0·84 males (95% UI 0·78–0·91) per female living with HIV in 2019, 0·99 male infections (0·91–1·10) for every female infection, and 1·02 male deaths (0·95–1·10) per female death. Global progress in incident cases and deaths between 2010 and 2019 was driven by sub-Saharan Africa (with a 28·52% decrease in incident cases, 95% UI 19·58–35·43, and a 39·66% decrease in deaths, 36·49–42·36). Elsewhere, the incidence remained stable or increased, whereas deaths generally decreased. In 2019, the global incidence-to-prevalence ratio was 0·05 (95% UI 0·05–0·06) and the global incidence-to-mortality ratio was 1·94 (1·76–2·12). No regions met suggested thresholds for progress. Interpretation: Sub-Saharan Africa had both the highest HIV burden and the greatest progress between 1990 and 2019. The number of incident cases and deaths in males and females approached parity in 2019, although there remained more females with HIV than males with HIV. Globally, the HIV epidemic is far from the UNAIDS benchmarks on progress metrics

Measuring routine childhood vaccination coverage in 204 countries and territories, 1980–2019 : a systematic analysis for the Global Burden of Disease Study 2020, Release 1

Background: Measuring routine childhood vaccination is crucial to inform global vaccine policies and programme implementation, and to track progress towards targets set by the Global Vaccine Action Plan (GVAP) and Immunization Agenda 2030. Robust estimates of routine vaccine coverage are needed to identify past successes and persistent vulnerabilities. Drawing from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2020, Release 1, we did a systematic analysis of global, regional, and national vaccine coverage trends using a statistical framework, by vaccine and over time. Methods: For this analysis we collated 55 326 country-specific, cohort-specific, year-specific, vaccine-specific, and dose-specific observations of routine childhood vaccination coverage between 1980 and 2019. Using spatiotemporal Gaussian process regression, we produced location-specific and year-specific estimates of 11 routine childhood vaccine coverage indicators for 204 countries and territories from 1980 to 2019, adjusting for biases in country-reported data and reflecting reported stockouts and supply disruptions. We analysed global and regional trends in coverage and numbers of zero-dose children (defined as those who never received a diphtheria-tetanus-pertussis [DTP] vaccine dose), progress towards GVAP targets, and the relationship between vaccine coverage and sociodemographic development. Findings: By 2019, global coverage of third-dose DTP (DTP3; 81·6% [95% uncertainty interval 80·4–82·7]) more than doubled from levels estimated in 1980 (39·9% [37·5–42·1]), as did global coverage of the first-dose measles-containing vaccine (MCV1; from 38·5% [35·4–41·3] in 1980 to 83·6% [82·3–84·8] in 2019). Third-dose polio vaccine (Pol3) coverage also increased, from 42·6% (41·4–44·1) in 1980 to 79·8% (78·4–81·1) in 2019, and global coverage of newer vaccines increased rapidly between 2000 and 2019. The global number of zero-dose children fell by nearly 75% between 1980 and 2019, from 56·8 million (52·6–60·9) to 14·5 million (13·4–15·9). However, over the past decade, global vaccine coverage broadly plateaued; 94 countries and territories recorded decreasing DTP3 coverage since 2010. Only 11 countries and territories were estimated to have reached the national GVAP target of at least 90% coverage for all assessed vaccines in 2019. Interpretation: After achieving large gains in childhood vaccine coverage worldwide, in much of the world this progress was stalled or reversed from 2010 to 2019. These findings underscore the importance of revisiting routine immunisation strategies and programmatic approaches, recentring service delivery around equity and underserved populations. Strengthening vaccine data and monitoring systems is crucial to these pursuits, now and through to 2030, to ensure that all children have access to, and can benefit from, lifesaving vaccines

Global burden of chronic respiratory diseases and risk factors, 1990–2019: an update from the Global Burden of Disease Study 2019

Background: Updated data on chronic respiratory diseases (CRDs) are vital in their prevention, control, and treatment in the path to achieving the third UN Sustainable Development Goals (SDGs), a one-third reduction in premature mortality from non-communicable diseases by 2030. We provided global, regional, and national estimates of the burden of CRDs and their attributable risks from 1990 to 2019. Methods: Using data from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019, we estimated mortality, years lived with disability, years of life lost, disability-adjusted life years (DALYs), prevalence, and incidence of CRDs, i.e. chronic obstructive pulmonary disease (COPD), asthma, pneumoconiosis, interstitial lung disease and pulmonary sarcoidosis, and other CRDs, from 1990 to 2019 by sex, age, region, and Socio-demographic Index (SDI) in 204 countries and territories. Deaths and DALYs from CRDs attributable to each risk factor were estimated according to relative risks, risk exposure, and the theoretical minimum risk exposure level input. Findings: In 2019, CRDs were the third leading cause of death responsible for 4.0 million deaths (95% uncertainty interval 3.6–4.3) with a prevalence of 454.6 million cases (417.4–499.1) globally. While the total deaths and prevalence of CRDs have increased by 28.5% and 39.8%, the age-standardised rates have dropped by 41.7% and 16.9% from 1990 to 2019, respectively. COPD, with 212.3 million (200.4–225.1) prevalent cases, was the primary cause of deaths from CRDs, accounting for 3.3 million (2.9–3.6) deaths. With 262.4 million (224.1–309.5) prevalent cases, asthma had the highest prevalence among CRDs. The age-standardised rates of all burden measures of COPD, asthma, and pneumoconiosis have reduced globally from 1990 to 2019. Nevertheless, the age-standardised rates of incidence and prevalence of interstitial lung disease and pulmonary sarcoidosis have increased throughout this period. Low- and low-middle SDI countries had the highest age-standardised death and DALYs rates while the high SDI quintile had the highest prevalence rate of CRDs. The highest deaths and DALYs from CRDs were attributed to smoking globally, followed by air pollution and occupational risks. Non-optimal temperature and high body-mass index were additional risk factors for COPD and asthma, respectively. Interpretation: Albeit the age-standardised prevalence, death, and DALYs rates of CRDs have decreased, they still cause a substantial burden and deaths worldwide. The high death and DALYs rates in low and low-middle SDI countries highlights the urgent need for improved preventive, diagnostic, and therapeutic measures. Global strategies for tobacco control, enhancing air quality, reducing occupational hazards, and fostering clean cooking fuels are crucial steps in reducing the burden of CRDs, especially in low- and lower-middle income countries. Funding: Bill & Melinda Gates Foundation

Psychological impact of COVID-19 on healthcare workers: cross-sectional analyses from 14 countries

Abstract Background Healthcare workers (HCWs) have been impacted psychologically due to their professional responsibilities over the prolonged era of the coronavirus disease 2019 (COVID-19) pandemic. The study aimed to identify the predictors of psychological distress, fear, and coping during the COVID-19 pandemic among HCWs. Methods A cross-sectional online survey was conducted among self-identified HCWs across 14 countries (12 from Asia and two from Africa). The Kessler Psychological Distress Scale, the Fear of COVID-19 Scale, and the Brief Resilient Coping Scale were used to assess the psychological distress, fear, and coping of HCWs, respectively. Results A total of 2447 HCWs participated; 36% were doctors, and 42% were nurses, with a mean age of 36 (±12) years, and 70% were females. Moderate to very-high psychological distress was prevalent in 67% of the HCWs; the lowest rate was reported in the United Arab Emirates (1%) and the highest in Indonesia (16%). The prevalence of high levels of fear was 20%; the lowest rate was reported in Libya (9%) and the highest in Egypt (32%). The prevalence of medium-to-high resilient coping was 63%; the lowest rate was reported in Libya (28%) and the highest in Syria (76%). Conclusion COVID-19 has augmented the psychological distress among HCWs. Factors identified in this study should be considered in managing the wellbeing of HCWs, who had been serving as the frontline drivers in managing the crisis successfully across all participating countries. Furthermore, interventions to address their psychological distress should be considered

Global, regional, and national burden of diabetes from 1990 to 2021, with projections of prevalence to 2050: a systematic analysis for the Global Burden of Disease Study 2021

Background: Diabetes is one of the leading causes of death and disability worldwide, and affects people regardless of country, age group, or sex. Using the most recent evidentiary and analytical framework from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD), we produced location-specific, age-specific, and sex-specific estimates of diabetes prevalence and burden from 1990 to 2021, the proportion of type 1 and type 2 diabetes in 2021, the proportion of the type 2 diabetes burden attributable to selected risk factors, and projections of diabetes prevalence through 2050. Methods: Estimates of diabetes prevalence and burden were computed in 204 countries and territories, across 25 age groups, for males and females separately and combined; these estimates comprised lost years of healthy life, measured in disability-adjusted life-years (DALYs; defined as the sum of years of life lost [YLLs] and years lived with disability [YLDs]). We used the Cause of Death Ensemble model (CODEm) approach to estimate deaths due to diabetes, incorporating 25 666 location-years of data from vital registration and verbal autopsy reports in separate total (including both type 1 and type 2 diabetes) and type-specific models. Other forms of diabetes, including gestational and monogenic diabetes, were not explicitly modelled. Total and type 1 diabetes prevalence was estimated by use of a Bayesian meta-regression modelling tool, DisMod-MR 2.1, to analyse 1527 location-years of data from the scientific literature, survey microdata, and insurance claims; type 2 diabetes estimates were computed by subtracting type 1 diabetes from total estimates. Mortality and prevalence estimates, along with standard life expectancy and disability weights, were used to calculate YLLs, YLDs, and DALYs. When appropriate, we extrapolated estimates to a hypothetical population with a standardised age structure to allow comparison in populations with different age structures. We used the comparative risk assessment framework to estimate the risk-attributable type 2 diabetes burden for 16 risk factors falling under risk categories including environmental and occupational factors, tobacco use, high alcohol use, high body-mass index (BMI), dietary factors, and low physical activity. Using a regression framework, we forecast type 1 and type 2 diabetes prevalence through 2050 with Socio-demographic Index (SDI) and high BMI as predictors, respectively. Findings: In 2021, there were 529 million (95% uncertainty interval [UI] 500–564) people living with diabetes worldwide, and the global age-standardised total diabetes prevalence was 6·1% (5·8–6·5). At the super-region level, the highest age-standardised rates were observed in north Africa and the Middle East (9·3% [8·7–9·9]) and, at the regional level, in Oceania (12·3% [11·5–13·0]). Nationally, Qatar had the world's highest age-specific prevalence of diabetes, at 76·1% (73·1–79·5) in individuals aged 75–79 years. Total diabetes prevalence—especially among older adults—primarily reflects type 2 diabetes, which in 2021 accounted for 96·0% (95·1–96·8) of diabetes cases and 95·4% (94·9–95·9) of diabetes DALYs worldwide. In 2021, 52·2% (25·5–71·8) of global type 2 diabetes DALYs were attributable to high BMI. The contribution of high BMI to type 2 diabetes DALYs rose by 24·3% (18·5–30·4) worldwide between 1990 and 2021. By 2050, more than 1·31 billion (1·22–1·39) people are projected to have diabetes, with expected age-standardised total diabetes prevalence rates greater than 10% in two super-regions: 16·8% (16·1–17·6) in north Africa and the Middle East and 11·3% (10·8–11·9) in Latin America and Caribbean. By 2050, 89 (43·6%) of 204 countries and territories will have an age-standardised rate greater than 10%. Interpretation: Diabetes remains a substantial public health issue. Type 2 diabetes, which makes up the bulk of diabetes cases, is largely preventable and, in some cases, potentially reversible if identified and managed early in the disease course. However, all evidence indicates that diabetes prevalence is increasing worldwide, primarily due to a rise in obesity caused by multiple factors. Preventing and controlling type 2 diabetes remains an ongoing challenge. It is essential to better understand disparities in risk factor profiles and diabetes burden across populations, to inform strategies to successfully control diabetes risk factors within the context of multiple and complex drivers. Funding: Bill & Melinda Gates Foundation