The Characteristics of Patients With Possible Transient Ischemic Attack and Minor Stroke in the Hunter and Manning Valley Regions, Australia (the INSIST Study)

Background: Transient ischemic attack (TIA) and minor stroke (TIAMS) are risk factors for stroke recurrence. Some TIAMS may be preventable by appropriate primary prevention. We aimed to recruit "possible-TIAMS" patients in the INternational comparison of Systems of care and patient outcomes In minor Stroke and TIA (INSIST) study. Methods: A prospective inception cohort study performed across 16 Hunter-Manning region, Australia, general practices in the catchment of one secondary-care acute neurovascular clinic. Possible-TIAMS patients were recruited from August 2012 to August 2016. We describe the baseline demographics, risk factors and pre-event medications of participating patients. Results: There were 613 participants (mean age; 69 ± 12 years, 335 women), and 604 (99%) were Caucasian. Hypertension was the most common risk factor (69%) followed by hyperlipidemia (52%), diabetes mellitus (17%), atrial fibrillation (AF) (17%), prior TIA (13%) or stroke (10%). Eighty-nine (36%) of the 249 participants taking antiplatelet therapy had no known history of cardiovascular morbidity. Of 102 participants with known AF, 91 (89%) had a CHA2DS2-VASc score ≥ 2 but only 47 (46%) were taking anticoagulation therapy. Among 304 participants taking an antiplatelet or anticoagulant agent, 30 (10%) had stopped taking these in the month prior to the index event. Conclusion: This study provides the first contemporary data on TIAMS or TIAMS-mimics in Australia. Community and health provider education is required to address the under-use of anticoagulation therapy in patients with known AF, possibly inappropriate use of antiplatelet therapy and possibly inappropriate discontinuation of antiplatelet or anticoagulation therapy.

New avenue for the geriatric depression scale: Rasch transformation enhances reliability of assessment

BACKGROUND

Depression is a common problem in older adults. The 15-item Geriatric Depression Scale (GDS-15) is a widely used psychometric tool for measuring depression in the elderly, but its psychometric properties have not been yet rigorously investigated. The aim was to evaluate psychometric properties of the GDS-15 and improve precision of the instrument by applying Rasch analysis and deriving conversion tables for transformation of raw scores into interval level data.

METHODS

The data was extracted from the prospective cohort Sydney Memory and Ageing Study of initially not demented individuals aged 70 years and older. The GDS-15 items scores of 212 participants (47.2% males) were analysed using the dichotomous Rasch model.

RESULTS

Initially poor reliability of the GDS-15, Person Separation Index (PSI) = 0.68, was improved by combining locally dependent items into seven super-items. These modifications improved reliability of the GDS-15 (PSI = 0.78) and resulted in the best Rasch model fit (χ²(28)=37.72, p = =0.104), strict unidimensionality and scale invariance across personal factors such as gender, diagnostic and language background.

LIMITATIONS

Presence of participants with cognitive impairment may be a potential limitation.

CONCLUSIONS

Reliability and psychometric characteristics of the GDS-15 were improved by minor modifications and now satisfy expectations of the unidimensional Rasch model. By using Rasch transformation tables published here psychiatrists, psychologists and researchers can transform GDS raw scores into interval-level data, which improves reliability of the GDS-15 without the need to modify its original response format. These findings increase accuracy of clinical psychometric assessments, leading to more precise diagnosis of depression in the elderly.

Incidence of Sports-Related Traumatic Brain Injury of All Severities: A Systematic Review

INTRODUCTION

Whilst there are many benefits to participating in sports and recreational activities, there is also a risk of injury including sports-related traumatic brain injury -(SR-TBI). To inform injury prevention initiatives, it is important to explore the burden of SR-TBI at the population level. This review aimed to estimate the incidence of SR-TBI in the general population across injury severities.

METHODS

Systematic search of electronic databases using keywords from 1965 until June 2019 facilitated by hand searches of reference lists. Original research reporting on the incidence of SR-TBI, capturing people of all ages in a well-defined population area was included. Studies were excluded if they focused on a specific sport(s) or population group. All studies were required to be published in the English language. Quality of studies was determined as poor, moderate or good based on the standards of reporting of neurological disorders criteria. Data on year(s) of data collection, diagnostic criterion, case ascertainment sources, population denominator and incidence per 100,000 and by age, sex, injury severity and sport were extracted by 2 authors independently using a standard data extraction form.

RESULTS

Following review of 11 studies meeting the inclusion criteria, the incidence of SR-TBI within hospital-based studies ranged between 3.5 and 31.5 per 100,000. One community-based study using multiple case ascertainment sources identified a higher incidence of 170 per 100,000. SR-TBI accounted for 1.2-30.3% of all TBIs. One study provided incidence data across a 5-year period suggesting an increasing trend in incidence over time. Males were more at risk than females (66.1-75.6%), and adolescents and young adults had the highest incidence of SR-TBI.

CONCLUSION

The primary objective of this review was to provide a summary of descriptive data on SR-TBI epidemiology at the population level. SR-TBI represented up to one-third of all causes of TBI. Trends in incidence by age and sport were challenging to determine due to lack of consistency in reporting as well as the small number of studies overall. Undertaking injury surveillance at all levels of TBI will assist with understanding the nature, mechanism of and surrounding events where injuries occur in sport.

Community Knowledge and Awareness of Stroke in New Zealand

INTRODUCTION

Community knowledge and stroke awareness is crucial for primary prevention of stroke and timely access to stroke treatments including acute reperfusion therapies. We conducted a national telephone survey to quantify the level of community stroke awareness.

METHODS

A random sample of 400 adults in New Zealand (NZ), stratified by the 4 main ethnic groups, was surveyed. Eligible participants answered stroke awareness questions using both unprompted (open-ended) and prompted questions (using a list). Proportional odds logistic regression models were used to identify factors associated with stroke awareness.

RESULTS

Only 1.5% of participants named stroke as a major cause of death. The stroke signs and symptoms most frequently identified from a list were sudden speech difficulty (94%) and sudden 1-sided weakness (92%). Without prompting, 78% of participants correctly identified at least 1 risk factor, 62% identified at least 2, and 35% identified 3 or more. When prompted with the list, scores increased 10-fold compared with unprompted responses. Ethnic disparities were observed, with Pacific peoples having the lowest level of awareness among the 4 ethnic groups. Higher education level, higher income, and personal experience of stroke were predictive of greater awareness (P ≤ .05).

CONCLUSIONS

Stroke was not recognized as a major cause of death. Although identification of stroke risk factors was high with prompting, awareness was low without prompting, particularly among those with lower education and income. Nationwide, culturally tailored public awareness campaigns are necessary to improve knowledge of stroke risk factors, recognition of stroke in the community and appropriate actions to take in cases of suspected stroke.

Trajectories in health recovery in the 12 months following a mild traumatic brain injury in children: findings from the BIONIC Study

INTRODUCTION There is growing consensus that adverse child outcomes may be evident in the early recovery phase following mild traumatic brain injury (TBI). However, controversy remains around the nature of children's longer-term recovery. AIM To examine child cognitive, behavioural and quality-of-life outcomes over 12 months following mild injury, and to identify prognostic factors associated with outcomes. METHODS A prospective sample of 222 children (aged 2-15 years at injury) with mild TBI was assessed using a cognitive testing battery and parent-report questionnaires at ≤ 14 days, 1, 6 and/or 12-months post-injury. RESULTS Parents reported significant improvements in their child's behavioural adjustment between baseline and 6 months (P = 0.003), with further improvements at 12 months following injury (P = 0.001). Cognitive recovery and quality-of-life improvements were more gradual with minimal changes in the first month (P > 0.05), but significant improvements by 12-months post-injury (P = 0.03, P = 0.02, respectively). Time since injury, male gender, living rurally and parent anxiety were associated with extent of recovery beyond the acute period. CONCLUSIONS Children's recovery from mild TBI continues beyond the initial 6 months following injury. Health-care providers need to be vigilant about the varying trajectories in children's recovery from TBI. On-going monitoring of children following injury will enable timely and proactive responses to persistent difficulties, with a view to minimising longer-term adverse consequences.

Measuring stroke and transient ischemic attack burden in New Zealand: Protocol for the fifth Auckland Regional Community Stroke Study (ARCOS V)

Aim: The goal of this paper is to provide a protocol for conducting a fifth population-based Auckland Regional Community Stroke study (ARCOS V) in New Zealand. Methods and Discussion: In this study, for the first time globally, (1) stroke and TIA burden will be determined using the currently used clinical and tissue-based definition of stroke, in addition to the WHO clinical classifications of stroke used in all previous ARCOS studies, as well as more advanced criteria recently suggested for an "ideal" population-based stroke incidence and outcomes study; and (2) age, sex, and ethnic-specific trends in stroke incidence and outcomes will be determined over the last four decades, including changes in the incidence of acute cerebrovascular events over the last decade. Furthermore, information at four time points over a 40-year period will allow the assessment of effects of recent changes such as implementation of the FAST campaign, ambulance pre-notification, and endovascular treatment. This will enable more accurate projections for health service planning and delivery. Conclusion: The methods of this study will provide a foundation for future similar population-based studies in other countries and populations.

Associations between brain drawings following mild traumatic brain injury and negative illness perceptions and post-concussion symptoms at 4 years

Characteristics of patient's drawings have been linked to short-term health-related outcomes across a range of health conditions. This study examined associations between brain drawings at 1 month and illness perceptions and post-concussion symptoms at 4 years in 92 adults following mild traumatic brain injury. Greater damage depicted at 1 month was correlated with perceived greater impact on life, duration of injury, symptoms of brain injury, emotional consequences and late-onset post-concussion symptoms. Results indicate that brain drawings shortly after traumatic brain injury offer a simple and insightful tool that may help to identify those who need additional support to improve long-term outcomes.

Global, regional, and national burden of neurological disorders, 1990-2016: a systematic analysis for the Global Burden of Disease Study 2016

BACKGROUND

Neurological disorders are increasingly recognised as major causes of death and disability worldwide. The aim of this analysis from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2016 is to provide the most comprehensive and up-to-date estimates of the global, regional, and national burden from neurological disorders.

METHODS

We estimated prevalence, incidence, deaths, and disability-adjusted life-years (DALYs; the sum of years of life lost [YLLs] and years lived with disability [YLDs]) by age and sex for 15 neurological disorder categories (tetanus, meningitis, encephalitis, stroke, brain and other CNS cancers, traumatic brain injury, spinal cord injury, Alzheimer's disease and other dementias, Parkinson's disease, multiple sclerosis, motor neuron diseases, idiopathic epilepsy, migraine, tension-type headache, and a residual category for other less common neurological disorders) in 195 countries from 1990 to 2016. DisMod-MR 2.1, a Bayesian meta-regression tool, was the main method of estimation of prevalence and incidence, and the Cause of Death Ensemble model (CODEm) was used for mortality estimation. We quantified the contribution of 84 risks and combinations of risk to the disease estimates for the 15 neurological disorder categories using the GBD comparative risk assessment approach.

FINDINGS

Globally, in 2016, neurological disorders were the leading cause of DALYs (276 million [95% UI 247-308]) and second leading cause of deaths (9·0 million [8·8-9·4]). The absolute number of deaths and DALYs from all neurological disorders combined increased (deaths by 39% [34-44] and DALYs by 15% [9-21]) whereas their age-standardised rates decreased (deaths by 28% [26-30] and DALYs by 27% [24-31]) between 1990 and 2016. The only neurological disorders that had a decrease in rates and absolute numbers of deaths and DALYs were tetanus, meningitis, and encephalitis. The four largest contributors of neurological DALYs were stroke (42·2% [38·6-46·1]), migraine (16·3% [11·7-20·8]), Alzheimer's and other dementias (10·4% [9·0-12·1]), and meningitis (7·9% [6·6-10·4]). For the combined neurological disorders, age-standardised DALY rates were significantly higher in males than in females (male-to-female ratio 1·12 [1·05-1·20]), but migraine, multiple sclerosis, and tension-type headache were more common and caused more burden in females, with male-to-female ratios of less than 0·7. The 84 risks quantified in GBD explain less than 10% of neurological disorder DALY burdens, except stroke, for which 88·8% (86·5-90·9) of DALYs are attributable to risk factors, and to a lesser extent Alzheimer's disease and other dementias (22·3% [11·8-35·1] of DALYs are risk attributable) and idiopathic epilepsy (14·1% [10·8-17·5] of DALYs are risk attributable).

INTERPRETATION

Globally, the burden of neurological disorders, as measured by the absolute number of DALYs, continues to increase. As populations are growing and ageing, and the prevalence of major disabling neurological disorders steeply increases with age, governments will face increasing demand for treatment, rehabilitation, and support services for neurological disorders. The scarcity of established modifiable risks for most of the neurological burden demonstrates that new knowledge is required to develop effective prevention and treatment strategies.

FUNDING

Bill & Melinda Gates Foundation.

Global, regional, and national burden of stroke, 1990-2016: a systematic analysis for the Global Burden of Disease Study 2016

BACKGROUND

Stroke is a leading cause of mortality and disability worldwide and the economic costs of treatment and post-stroke care are substantial. The Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) provides a systematic, comparable method of quantifying health loss by disease, age, sex, year, and location to provide information to health systems and policy makers on more than 300 causes of disease and injury, including stroke. The results presented here are the estimates of burden due to overall stroke and ischaemic and haemorrhagic stroke from GBD 2016.

METHODS

We report estimates and corresponding uncertainty intervals (UIs), from 1990 to 2016, for incidence, prevalence, deaths, years of life lost (YLLs), years lived with disability (YLDs), and disability-adjusted life-years (DALYs). DALYs were generated by summing YLLs and YLDs. Cause-specific mortality was estimated using an ensemble modelling process with vital registration and verbal autopsy data as inputs. Non-fatal estimates were generated using Bayesian meta-regression incorporating data from registries, scientific literature, administrative records, and surveys. The Socio-demographic Index (SDI), a summary indicator generated using educational attainment, lagged distributed income, and total fertility rate, was used to group countries into quintiles.

FINDINGS

In 2016, there were 5·5 million (95% UI 5·3 to 5·7) deaths and 116·4 million (111·4 to 121·4) DALYs due to stroke. The global age-standardised mortality rate decreased by 36·2% (-39·3 to -33·6) from 1990 to 2016, with decreases in all SDI quintiles. Over the same period, the global age-standardised DALY rate declined by 34·2% (-37·2 to -31·5), also with decreases in all SDI quintiles. There were 13·7 million (12·7 to 14·7) new stroke cases in 2016. Global age-standardised incidence declined by 8·1% (-10·7 to -5·5) from 1990 to 2016 and decreased in all SDI quintiles except the middle SDI group. There were 80·1 million (74·1 to 86·3) prevalent cases of stroke globally in 2016; 41·1 million (38·0 to 44·3) in women and 39·0 million (36·1 to 42·1) in men.

INTERPRETATION

Although age-standardised mortality rates have decreased sharply from 1990 to 2016, the decrease in age-standardised incidence has been less steep, indicating that the burden of stroke is likely to remain high. Planned updates to future GBD iterations include generating separate estimates for subarachnoid haemorrhage and intracerebral haemorrhage, generating estimates of transient ischaemic attack, and including atrial fibrillation as a risk factor.

FUNDING

Bill & Melinda Gates Foundation.

The burden of headache disorders in the Eastern Mediterranean Region, 1990-2016: findings from the Global Burden of Disease study 2016

OBJECTIVES

Using the findings of the Global Burden of Disease Study (GBD), we report the burden of primary headache disorders in the Eastern Mediterranean Region (EMR) from 1990 to 2016.

METHODS

We modelled headache disorders using DisMod-MR 2.1 Bayesian meta-regression tool to ensure consistency between prevalence, incidence, and remission. Years lived with disability (YLDs) were calculated by multiplying prevalence and disability weight (DW) of migraine and tension-type headache (TTH). We assumed primary headache disorders as non-fatal, so their YLD is equal to disability-adjusted life years (DALYs).

RESULTS

Migraine and TTH were the second and twentieth leading causes of YLDs in EMR. Between 1990 and 2016, the absolute YLD numbers of migraine and TTH increased from 2.3 million (95% uncertainty interval (UI): 1.5-3.2) to 4.7 million (95%UI: 3-6.5) and from 383 thousand (95%UI: 240-562) to 816 thousand (95%UI: 516-1221), respectively. During the same period, age-standardised YLD rates of migraine and TTH in EMR increased by 0.7% and 2.5%, respectively, in comparison to a small decrease in the global rates (0.2% decrease in migraine and TTH). The bulk of burden due to headache occurred in the 30-49 year age group, with a peak at ages 35-44 years. The age-standardised YLD rates of both headache disorders were higher in women with female to male ratio of 1.69 for migraine and 1.38 for TTH. All countries of the EMR except for Somalia and Djibouti had higher age-standardised YLD rates for migraine and TTH in compare to the global rates. Libya and Saudi Arabia had the highest increase in age-standardised YLD rates of migraine and TTH, respectively.

CONCLUSION

The findings of this study show that primary headache disorders are a major and a growing cause of disability in EMR. Since 1990, burden of primary headache disorders has constantly been higher in EMR compared to rest of the world, which indicates that health systems in EMR must focus further on developing and implementing preventive and management strategies to control headache.

Priorities to reduce the burden of stroke in Latin American countries

The large and increasing burden of stroke in Latin American countries, and the need to meet the UN and WHO requirements for reducing the burden from non-communicable disorders (including stroke), brought together stroke experts and representatives of the Ministries of Health of 13 Latin American countries for the 1st Latin American Stroke Ministerial meeting in Gramado, Brazil, to discuss the problem and identify ways of cooperating to reduce the burden of stroke in the region. Discussions were focused on the regional and country-specific activities associated with stroke prevention and treatment, including public stroke awareness, prevention strategies, delivery and organisation of care, clinical practice gaps, and unmet needs. The meeting culminated with the adoption of the special Gramado Declaration, signed by all Ministerial officials who attended the meeting. With agreed priorities for stroke prevention, treatment, and research, an opportunity now exists to translate this Declaration into an action plan to reduce the burden of stroke.

Longitudinal patterns of behavior, cognition, and quality of life after mild traumatic brain injury in children: BIONIC study findings

Background: Research following mild traumatic brain injury (mTBI) during childhood predominantly examines recovery up to 12 months post-injury. Objectives: To determine children's longer-term (4 years) patterns and predictors of recovery. Methods: Parents of 196 children (aged 1-15 years) completed the Behaviour Assessment System for Children and Pediatric Quality of Life Inventory at baseline, 1, 6, 12, and 48 months post-injury. Children aged ≥8 years at each assessment completed a computerized neurocognitive testing battery. At 1 month, parents completed the Hospital Anxiety and Depression Scale. Multilevel modeling accounted for repeated measures. Results: Children had significantly fewer child behavior problems, better adaptability, and improved quality of life after 12 months. Concurrent improvements in overall neurocognitive function were no longer significant once adjusted for age, gender, and socio-economic status. From 12 to 48 months, quality of life reduced significantly while child behavior and neurocognition plateaued. Child behavior problems and worse quality of life were associated with parental anxiety and lower socio-economic status. Conclusions: Children's recovery in the year following mTBI appears to plateau from 12 to 48 months, with a concomitant reduction in quality of life. Identification and treatment of parent mental health issues may reduce the exacerbation of negative child outcomes following mTBI.

Global, regional, and national burden of multiple sclerosis 1990-2016: a systematic analysis for the Global Burden of Disease Study 2016

BACKGROUND

Multiple sclerosis is the most common inflammatory neurological disease in young adults. The Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) provides a systematic method of quantifying various effects of a given condition by demographic variables and geography. In this systematic analysis, we quantified the global burden of multiple sclerosis and its relationship with country development level.

METHODS

We assessed the epidemiology of multiple sclerosis from 1990 to 2016. Epidemiological outcomes for multiple sclerosis were modelled with DisMod-MR version 2.1, a Bayesian meta-regression framework widely used in GBD epidemiological modelling. Assessment of multiple sclerosis as the cause of death was based on 13 110 site-years of vital registration data analysed in the GBD's cause of death ensemble modelling module, which is designed to choose the optimum combination of mathematical models and predictive covariates based on out-of-sample predictive validity testing. Data on prevalence and deaths are summarised in the indicator, disability-adjusted life-years (DALYs), which was calculated as the sum of years of life lost (YLLs) and years of life lived with a disability. We used the Socio-demographic Index, a composite indicator of income per person, years of education, and fertility, to assess relations with development level.

FINDINGS

In 2016, there were 2 221 188 prevalent cases of multiple sclerosis (95% uncertainty interval [UI] 2 033 866-2 436 858) globally, which corresponded to a 10·4% (9·1 to 11·8) increase in the age-standardised prevalence since 1990. The highest age-standardised multiple sclerosis prevalence estimates per 100 000 population were in high-income North America (164·6, 95% UI, 153·2 to 177·1), western Europe (127·0, 115·4 to 139·6), and Australasia (91·1, 81·5 to 101·7), and the lowest were in eastern sub-Saharan Africa (3·3, 2·9-3·8), central sub-Saharan African (2·8, 2·4 to 3·1), and Oceania (2·0, 1·71 to 2·29). There were 18 932 deaths due to multiple sclerosis (95% UI 16 577 to 21 033) and 1 151 478 DALYs (968 605 to 1 345 776) due to multiple sclerosis in 2016. Globally, age-standardised death rates decreased significantly (change -11·5%, 95% UI -35·4 to -4·7), whereas the change in age-standardised DALYs was not significant (-4·2%, -16·4 to 0·8). YLLs due to premature death were greatest in the sixth decade of life (22·05, 95% UI 19·08 to 25·34). Changes in age-standardised DALYs assessed with the Socio-demographic Index between 1990 and 2016 were variable.

INTERPRETATION

Multiple sclerosis is not common but is a potentially severe cause of neurological disability throughout adult life. Prevalence has increased substantially in many regions since 1990. These findings will be useful for resource allocation and planning in health services. Many regions worldwide have few or no epidemiological data on multiple sclerosis, and more studies are needed to make more accurate estimates.

FUNDING

Bill & Melinda Gates Foundation.

Anthology of stroke epidemiology in the 20th and 21st centuries: Assessing the past, the present, and envisioning the future

This narrative overview of stroke epidemiology shows dramatic changes in stroke incidence, prevalence, mortality, disability, and the understanding of risk factors and primary stroke prevention strategies over the last few decades. Likely future directions of stroke epidemiology and prevention are outlined.

Global, regional, and national burden of traumatic brain injury and spinal cord injury, 1990-2016: a systematic analysis for the Global Burden of Disease Study 2016

BACKGROUND

Traumatic brain injury (TBI) and spinal cord injury (SCI) are increasingly recognised as global health priorities in view of the preventability of most injuries and the complex and expensive medical care they necessitate. We aimed to measure the incidence, prevalence, and years of life lived with disability (YLDs) for TBI and SCI from all causes of injury in every country, to describe how these measures have changed between 1990 and 2016, and to estimate the proportion of TBI and SCI cases caused by different types of injury.

METHODS

We used results from the Global Burden of Diseases, Injuries, and Risk Factors (GBD) Study 2016 to measure the global, regional, and national burden of TBI and SCI by age and sex. We measured the incidence and prevalence of all causes of injury requiring medical care in inpatient and outpatient records, literature studies, and survey data. By use of clinical record data, we estimated the proportion of each cause of injury that required medical care that would result in TBI or SCI being considered as the nature of injury. We used literature studies to establish standardised mortality ratios and applied differential equations to convert incidence to prevalence of long-term disability. Finally, we applied GBD disability weights to calculate YLDs. We used a Bayesian meta-regression tool for epidemiological modelling, used cause-specific mortality rates for non-fatal estimation, and adjusted our results for disability experienced with comorbid conditions. We also analysed results on the basis of the Socio-demographic Index, a compound measure of income per capita, education, and fertility.

FINDINGS

In 2016, there were 27·08 million (95% uncertainty interval [UI] 24·30-30·30 million) new cases of TBI and 0·93 million (0·78-1·16 million) new cases of SCI, with age-standardised incidence rates of 369 (331-412) per 100 000 population for TBI and 13 (11-16) per 100 000 for SCI. In 2016, the number of prevalent cases of TBI was 55·50 million (53·40-57·62 million) and of SCI was 27·04 million (24·98-30·15 million). From 1990 to 2016, the age-standardised prevalence of TBI increased by 8·4% (95% UI 7·7 to 9·2), whereas that of SCI did not change significantly (-0·2% [-2·1 to 2·7]). Age-standardised incidence rates increased by 3·6% (1·8 to 5·5) for TBI, but did not change significantly for SCI (-3·6% [-7·4 to 4·0]). TBI caused 8·1 million (95% UI 6·0-10·4 million) YLDs and SCI caused 9·5 million (6·7-12·4 million) YLDs in 2016, corresponding to age-standardised rates of 111 (82-141) per 100 000 for TBI and 130 (90-170) per 100 000 for SCI. Falls and road injuries were the leading causes of new cases of TBI and SCI in most regions.

INTERPRETATION

TBI and SCI constitute a considerable portion of the global injury burden and are caused primarily by falls and road injuries. The increase in incidence of TBI over time might continue in view of increases in population density, population ageing, and increasing use of motor vehicles, motorcycles, and bicycles. The number of individuals living with SCI is expected to increase in view of population growth, which is concerning because of the specialised care that people with SCI can require. Our study was limited by data sparsity in some regions, and it will be important to invest greater resources in collection of data for TBI and SCI to improve the accuracy of future assessments.

FUNDING

Bill & Melinda Gates Foundation.

Global, regional, and national burden of Alzheimer's disease and other dementias, 1990-2016: a systematic analysis for the Global Burden of Disease Study 2016

BACKGROUND

The number of individuals living with dementia is increasing, negatively affecting families, communities, and health-care systems around the world. A successful response to these challenges requires an accurate understanding of the dementia disease burden. We aimed to present the first detailed analysis of the global prevalence, mortality, and overall burden of dementia as captured by the Global Burden of Diseases, Injuries, and Risk Factors (GBD) Study 2016, and highlight the most important messages for clinicians and neurologists.

METHODS

GBD 2016 obtained data on dementia from vital registration systems, published scientific literature and surveys, and data from health-service encounters on deaths, excess mortality, prevalence, and incidence from 195 countries and territories from 1990 to 2016, through systematic review and additional data-seeking efforts. To correct for differences in cause of death coding across time and locations, we modelled mortality due to dementia using prevalence data and estimates of excess mortality derived from countries that were most likely to code deaths to dementia relative to prevalence. Data were analysed by standardised methods to estimate deaths, prevalence, years of life lost (YLLs), years of life lived with disability (YLDs), and disability-adjusted life-years (DALYs; computed as the sum of YLLs and YLDs), and the fractions of these metrics that were attributable to four risk factors that met GBD criteria for assessment (high body-mass index [BMI], high fasting plasma glucose, smoking, and a diet high in sugar-sweetened beverages).

FINDINGS

In 2016, the global number of individuals who lived with dementia was 43·8 million (95% uncertainty interval [UI] 37·8-51·0), increased from 20.2 million (17·4-23·5) in 1990. This increase of 117% (95% UI 114-121) contrasted with a minor increase in age-standardised prevalence of 1·7% (1·0-2·4), from 701 cases (95% UI 602-815) per 100 000 population in 1990 to 712 cases (614-828) per 100 000 population in 2016. More women than men had dementia in 2016 (27·0 million, 95% UI 23·3-31·4, vs 16.8 million, 14.4-19.6), and dementia was the fifth leading cause of death globally, accounting for 2·4 million (95% UI 2·1-2·8) deaths. Overall, 28·8 million (95% UI 24·5-34·0) DALYs were attributed to dementia; 6·4 million (95% UI 3·4-10·5) of these could be attributed to the modifiable GBD risk factors of high BMI, high fasting plasma glucose, smoking, and a high intake of sugar-sweetened beverages.

INTERPRETATION

The global number of people living with dementia more than doubled from 1990 to 2016, mainly due to increases in population ageing and growth. Although differences in coding for causes of death and the heterogeneity in case-ascertainment methods constitute major challenges to the estimation of the burden of dementia, future analyses should improve on the methods for the correction of these biases. Until breakthroughs are made in prevention or curative treatment, dementia will constitute an increasing challenge to health-care systems worldwide.

FUNDING

Bill & Melinda Gates Foundation.

Global, Regional, and Country-Specific Lifetime Risks of Stroke, 1990 and 2016

BACKGROUND

The lifetime risk of stroke has been calculated in a limited number of selected populations. We sought to estimate the lifetime risk of stroke at the regional, country, and global level using data from a comprehensive study of the prevalence of major diseases.

METHODS

We used the Global Burden of Disease (GBD) Study 2016 estimates of stroke incidence and the competing risks of death from any cause other than stroke to calculate the cumulative lifetime risks of first stroke, ischemic stroke, or hemorrhagic stroke among adults 25 years of age or older. Estimates of the lifetime risks in the years 1990 and 2016 were compared. Countries were categorized into quintiles of the sociodemographic index (SDI) used in the GBD Study, and the risks were compared across quintiles. Comparisons were made with the use of point estimates and uncertainty intervals representing the 2.5th and 97.5th percentiles around the estimate.

RESULTS

The estimated global lifetime risk of stroke from the age of 25 years onward was 24.9% (95% uncertainty interval, 23.5 to 26.2); the risk among men was 24.7% (95% uncertainty interval, 23.3 to 26.0), and the risk among women was 25.1% (95% uncertainty interval, 23.7 to 26.5). The risk of ischemic stroke was 18.3%, and the risk of hemorrhagic stroke was 8.2%. In high-SDI, high-middle-SDI, and low-SDI countries, the estimated lifetime risk of stroke was 23.5%, 31.1% (highest risk), and 13.2% (lowest risk), respectively; the 95% uncertainty intervals did not overlap between these categories. The highest estimated lifetime risks of stroke according to GBD region were in East Asia (38.8%), Central Europe (31.7%), and Eastern Europe (31.6%), and the lowest risk was in eastern sub-Saharan Africa (11.8%). The mean global lifetime risk of stroke increased from 22.8% in 1990 to 24.9% in 2016, a relative increase of 8.9% (95% uncertainty interval, 6.2 to 11.5); the competing risk of death from any cause other than stroke was considered in this calculation.

CONCLUSIONS

In 2016, the global lifetime risk of stroke from the age of 25 years onward was approximately 25% among both men and women. There was geographic variation in the lifetime risk of stroke, with the highest risks in East Asia, Central Europe, and Eastern Europe. (Funded by the Bill and Melinda Gates Foundation.).

The burden of stroke in China: Results from a nationwide population-based epidemiological survey

Stroke is a serious threat to human health that often leads to severe complications, and currently ranks first as leading cause of death in China. However, reliable data on stroke burden in China in the 21st century are lacking. We used the data from NESS-China (National Epidemiological Survey of Stroke in China) for assessing the adverse health effects of stroke in Chinese population. We carried out inter-regional comparative study in order to obtain regular burden related characteristics of stroke in China, as measured by YLLs (years of life lost due to premature mortality), YLDs (years lived with disability) and DALYs (disability adjusted life years). Amongst the nationwide population of 596,536 individuals of all ages in 2013, the YLLs for stroke was 1748, the YLDs was 262, and the DALYs was 2010(per 100,000). The gender subtype analysis of DALYs was 2171(male) and 1848(female). The YLLs, YLDs and DALYs in rural areas were higher compared to urban areas. Among the 18 age groups, the highest YLLs was observed in ≥ 80 years old group. The impact of stroke on Chinese population is more severe compared to the global average levels. Stroke results as the main cause of YLLs in China, while there is no significant difference for the YLDs. Nevertheless, DALYs caused by stroke rank 3th in global epidemiologic study territories, 1st in China.

Global, regional, and national burden of motor neuron diseases 1990-2016: a systematic analysis for the Global Burden of Disease Study 2016

BACKGROUND

Understanding how prevalence, incidence, and mortality of motor neuron diseases change over time and by location is crucial for understanding the causes of these disorders and for health-care planning. Our aim was to produce estimates of incidence, prevalence, and disability-adjusted life-years (DALYs) for motor neuron diseases for 195 countries and territories from 1990 to 2016 as part of the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2016.

METHODS

The motor neuron diseases included in this study were amyotrophic lateral sclerosis, spinal muscular atrophy, hereditary spastic paraplegia, primary lateral sclerosis, progressive muscular atrophy, and pseudobulbar palsy. Incidence, prevalence, and DALYs were estimated using a Bayesian meta-regression model. We analysed 14 165 site-years of vital registration cause of death data using the GBD 2016 cause of death ensemble model. The 84 risk factors quantified in GBD 2016 were tested for an association with incidence or death from motor neuron diseases. We also explored the relationship between Socio-demographic Index (SDI; a compound measure of income per capita, education, and fertility) and age-standardised DALYs of motor neuron diseases.

FINDINGS

In 2016, globally, 330 918 (95% uncertainty interval [UI] 299 522-367 254) individuals had a motor neuron disease. Motor neuron diseases have caused 926 090 (881 566-961 758) DALYs and 34 325 (33 051-35 364) deaths in 2016. The worldwide all-age prevalence was 4·5 (4·1-5·0) per 100 000 people, with an increase in age-standardised prevalence of 4·5% (3·4-5·7) over the study period. The all-age incidence was 0·78 (95% UI 0·71-0·86) per 100 000 person-years. No risk factor analysed in GBD showed an association with motor neuron disease incidence. The largest age-standardised prevalence was in high SDI regions: high-income North America (16·8, 95% UI 15·8-16·9), Australasia (14·7, 13·5-16·1), and western Europe (12·9, 11·7-14·1). However, the prevalence and incidence were lower than expected based on SDI in high-income Asia Pacific.

INTERPRETATION

Motor neuron diseases have low prevalence and incidence, but cause severe disability with a high fatality rate. Incidence of motor neuron diseases has geographical heterogeneity, which is not explained by any risk factors quantified in GBD, suggesting other unmeasured risk factors might have a role. Between 1990 and 2016, the burden of motor neuron diseases has increased substantially. The estimates presented here, as well as future estimates based on data from a greater number of countries, will be important in the planning of services for people with motor neuron diseases worldwide.

FUNDING

Bill & Melinda Gates Foundation.

Global, regional, and national burden of meningitis, 1990-2016: a systematic analysis for the Global Burden of Disease Study 2016

BACKGROUND

Acute meningitis has a high case-fatality rate and survivors can have severe lifelong disability. We aimed to provide a comprehensive assessment of the levels and trends of global meningitis burden that could help to guide introduction, continuation, and ongoing development of vaccines and treatment programmes.

METHODS

The Global Burden of Diseases, Injuries, and Risk Factors (GBD) 2016 study estimated meningitis burden due to one of four types of cause: pneumococcal, meningococcal, Haemophilus influenzae type b, and a residual category of other causes. Cause-specific mortality estimates were generated via cause of death ensemble modelling of vital registration and verbal autopsy data that were subject to standardised data processing algorithms. Deaths were multiplied by the GBD standard life expectancy at age of death to estimate years of life lost, the mortality component of disability-adjusted life-years (DALYs). A systematic analysis of relevant publications and hospital and claims data was used to estimate meningitis incidence via a Bayesian meta-regression tool. Meningitis deaths and cases were split between causes with meta-regressions of aetiological proportions of mortality and incidence, respectively. Probabilities of long-term impairment by cause of meningitis were applied to survivors and used to estimate years of life lived with disability (YLDs). We assessed the relationship between burden metrics and Socio-demographic Index (SDI), a composite measure of development based on fertility, income, and education.

FINDINGS

Global meningitis deaths decreased by 21·0% from 1990 to 2016, from 403 012 (95% uncertainty interval [UI] 319 426-458 514) to 318 400 (265 218-408 705). Incident cases globally increased from 2·50 million (95% UI 2·19-2·91) in 1990 to 2·82 million (2·46-3·31) in 2016. Meningitis mortality and incidence were closely related to SDI. The highest mortality rates and incidence rates were found in the peri-Sahelian countries that comprise the African meningitis belt, with six of the ten countries with the largest number of cases and deaths being located within this region. Haemophilus influenzae type b was the most common cause of incident meningitis in 1990, at 780 070 cases (95% UI 613 585-978 219) globally, but decreased the most (-49·1%) to become the least common cause in 2016, with 397 297 cases (291 076-533 662). Meningococcus was the leading cause of meningitis mortality in 1990 (192 833 deaths [95% UI 153 358-221 503] globally), whereas other meningitis was the leading cause for both deaths (136 423 [112 682-178 022]) and incident cases (1·25 million [1·06-1·49]) in 2016. Pneumococcus caused the largest number of YLDs (634 458 [444 787-839 749]) in 2016, owing to its more severe long-term effects on survivors. Globally in 2016, 1·48 million (1·04-1·96) YLDs were due to meningitis compared with 21·87 million (18·20-28·28) DALYs, indicating that the contribution of mortality to meningitis burden is far greater than the contribution of disabling outcomes.

INTERPRETATION

Meningitis burden remains high and progress lags substantially behind that of other vaccine-preventable diseases. Particular attention should be given to developing vaccines with broader coverage against the causes of meningitis, making these vaccines affordable in the most affected countries, improving vaccine uptake, improving access to low-cost diagnostics and therapeutics, and improving support for disabled survivors. Substantial uncertainty remains around pathogenic causes and risk factors for meningitis. Ongoing, active cause-specific surveillance of meningitis is crucial to continue and to improve monitoring of meningitis burdens and trends throughout the world.

FUNDING

Bill & Melinda Gates Foundation.