The Burden of Proof studies: assessing the evidence of risk.

Exposure to risks throughout life results in a wide variety of outcomes. Objectively judging the relative impact of these risks on personal and population health is fundamental to individual survival and societal prosperity. Existing mechanisms to quantify and rank the magnitude of these myriad effects and the uncertainty in their estimation are largely subjective, leaving room for interpretation that can fuel academic controversy and add to confusion when communicating risk. We present a new suite of meta-analyses-termed the Burden of Proof studies-designed specifically to help evaluate these methodological issues objectively and quantitatively. Through this data-driven approach that complements existing systems, including GRADE and Cochrane Reviews, we aim to aggregate evidence across multiple studies and enable a quantitative comparison of risk-outcome pairs. We introduce the burden of proof risk function (BPRF), which estimates the level of risk closest to the null hypothesis that is consistent with available data. Here we illustrate the BPRF methodology for the evaluation of four exemplar risk-outcome pairs: smoking and lung cancer, systolic blood pressure and ischemic heart disease, vegetable consumption and ischemic heart disease, and unprocessed red meat consumption and ischemic heart disease. The strength of evidence for each relationship is assessed by computing and summarizing the BPRF, and then translating the summary to a simple star rating. The Burden of Proof methodology provides a consistent way to understand, evaluate and summarize evidence of risk across different risk-outcome pairs, and informs risk analysis conducted as part of the Global Burden of Diseases, Injuries, and Risk Factors Study.

A comprehensive analysis of mortality-related health metrics associated with mental disorders: a nationwide, register-based cohort study.

BACKGROUND: Systematic reviews have consistently shown that individuals with mental disorders have an increased risk of premature mortality. Traditionally, this evidence has been based on relative risks or crude estimates of reduced life expectancy. The aim of this study was to compile a comprehensive analysis of mortality-related health metrics associated with mental disorders, including sex-specific and age-specific mortality rate ratios (MRRs) and life-years lost (LYLs), a measure that takes into account age of onset of the disorder. METHODS: In this population-based cohort study, we included all people younger than 95 years of age who lived in Denmark at some point between Jan 1, 1995, and Dec 31, 2015. Information on mental disorders was obtained from the Danish Psychiatric Central Research Register and the date and cause of death was obtained from the Danish Register of Causes of Death. We classified mental disorders into ten groups and causes of death into 11 groups, which were further categorised into natural causes (deaths from diseases and medical conditions) and external causes (suicide, homicide, and accidents). For each specific mental disorder, we estimated MRRs using Poisson regression models, adjusting for sex, age, and calendar time, and excess LYLs (ie, difference in LYLs between people with a mental disorder and the general population) for all-cause mortality and for each specific cause of death. FINDINGS: 7 369 926 people were included in our analysis. We found that mortality rates were higher for people with a diagnosis of a mental disorder than for the general Danish population (28·70 deaths [95% CI 28·57-28·82] vs 12·95 deaths [12·93-12·98] per 1000 person-years). Additionally, all types of disorders were associated with higher mortality rates, with MRRs ranging from 1·92 (95% CI 1·91-1·94) for mood disorders to 3·91 (3·87-3·94) for substance use disorders. All types of mental disorders were associated with shorter life expectancies, with excess LYLs ranging from 5·42 years (95% CI 5·36-5·48) for organic disorders in females to 14·84 years (14·70-14·99) for substance use disorders in males. When we examined specific causes of death, we found that males with any type of mental disorder lost fewer years due to neoplasm-related deaths compared with the general population, although their cancer mortality rates were higher. INTERPRETATION: Mental disorders are associated with premature mortality. We provide a comprehensive analysis of mortality by different types of disorders, presenting both MRRs and premature mortality based on LYLs, displayed by age, sex, and cause of death. By providing accurate estimates of premature mortality, we reveal previously underappreciated features related to competing risks and specific causes of death. FUNDING: Danish National Research Foundation.

Burden of non-communicable diseases in sub-Saharan Africa, 1990-2017: results from the Global Burden of Disease Study 2017.

BACKGROUND: Although the burden of disease in sub-Saharan Africa continues to be dominated by infectious diseases, countries in this region are undergoing a demographic transition leading to increasing prevalence of non-communicable diseases (NCDs). To inform health system responses to these changing patterns of disease, we aimed to assess changes in the burden of NCDs in sub-Saharan Africa from 1990 to 2017. METHODS: We used data from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2017 to analyse the burden of NCDs in sub-Saharan Africa in terms of disability-adjusted life-years (DALYs)-with crude counts as well as all-age and age-standardised rates per 100 000 population-with 95% uncertainty intervals (UIs). We examined changes in burden between 1990 and 2017, and differences across age, sex, and regions. We also compared the observed NCD burden across countries with the expected values based on a country's Socio-demographic Index. FINDINGS: All-age total DALYs due to NCDs increased by 67·0% between 1990 (90·6 million [95% UI 81·0-101·9]) and 2017 (151·3 million [133·4-171·8]), reflecting an increase in the proportion of total DALYs attributable to NCDs (from 18·6% [95% UI 17·1-20·4] to 29·8% [27·6-32·0] of the total burden). Although most of this increase can be explained by population growth and ageing, the age-standardised DALY rate (per 100 000 population) due to NCDs in 2017 (21 757·7 DALYs [95% UI 19 377·1-24 380·7]) was almost equivalent to that of communicable, maternal, neonatal, and nutritional diseases (26 491·6 DALYs [25 165·2-28 129·8]). Cardiovascular diseases were the second leading cause of NCD burden in 2017, resulting in 22·9 million (21·5-24·3) DALYs (15·1% of the total NCD burden), after the group of disorders categorised as other NCDs (28·8 million [25·1-33·0] DALYs, 19·1%). These categories were followed by neoplasms, mental disorders, and digestive diseases. Although crude DALY rates for all NCDs have decreased slightly across sub-Saharan Africa, age-standardised rates are on the rise in some countries (particularly those in southern sub-Saharan Africa) and for some NCDs (such as diabetes and some cancers, including breast and prostate cancer). INTERPRETATION: NCDs in sub-Saharan Africa are posing an increasing challenge for health systems, which have to date largely focused on tackling infectious diseases and maternal, neonatal, and child deaths. To effectively address these changing needs, countries in sub-Saharan Africa require detailed epidemiological data on NCDs. FUNDING: Bill & Melinda Gates Foundation, National Health and Medical Research Centre (Australia).

Global statistics on alcohol, tobacco and illicit drug use: 2017 status report.

AIMS: This review provides an up-to-date curated source of information on alcohol, tobacco and illicit drug use and their associated mortality and burden of disease. Limitations in the data are also discussed, including how these can be addressed in the future. METHODS: Online data sources were identified through expert review. Data were obtained mainly from the World Health Organization, United Nations Office on Drugs and Crime and Institute for Health Metrics and Evaluation. RESULTS: In 2015, the estimated prevalence among the adult population was 18.4% for heavy episodic alcohol use (in the past 30 days); 15.2% for daily tobacco smoking; and 3.8, 0.77, 0.37 and 0.35% for past-year cannabis, amphetamine, opioid and cocaine use, respectively. European regions had the highest prevalence of heavy episodic alcohol use and daily tobacco use. The age-standardized prevalence of alcohol dependence was 843.2 per 100 000 people; for cannabis, opioids, amphetamines and cocaine dependence it was 259.3, 220.4, 86.0 and 52.5 per 100 000 people, respectively. High-income North America region had among the highest rates of cannabis, opioid and cocaine dependence. Attributable disability-adjusted life-years (DALYs) were highest for tobacco smoking (170.9 million DALYs), followed by alcohol (85.0 million) and illicit drugs (27.8 million). Substance-attributable mortality rates were highest for tobacco smoking (110.7 deaths per 100 000 people), followed by alcohol and illicit drugs (33.0 and 6.9 deaths per 100 000 people, respectively). Attributable age-standardized mortality rates and DALYs for alcohol and illicit drugs were highest in eastern Europe; attributable age-standardized tobacco mortality rates and DALYs were highest in Oceania. CONCLUSIONS: In 2015 alcohol use and tobacco smoking use between them cost the human population more than a quarter of a billion disability-adjusted life years, with illicit drugs costing further tens of millions. Europeans suffered proportionately more, but in absolute terms the mortality rate was greatest in low- and middle-income countries with large populations and where the quality of data was more limited. Better standardized and rigorous methods for data collection, collation and reporting are needed to assess more accurately the geographical and temporal trends in substance use and its disease burden.

The State of US Health, 1990-2016: Burden of Diseases, Injuries, and Risk Factors Among US States.

Introduction: Several studies have measured health outcomes in the United States, but none have provided a comprehensive assessment of patterns of health by state. Objective: To use the results of the Global Burden of Disease Study (GBD) to report trends in the burden of diseases, injuries, and risk factors at the state level from 1990 to 2016. Design and Setting: A systematic analysis of published studies and available data sources estimates the burden of disease by age, sex, geography, and year. Main Outcomes and Measures: Prevalence, incidence, mortality, life expectancy, healthy life expectancy (HALE), years of life lost (YLLs) due to premature mortality, years lived with disability (YLDs), and disability-adjusted life-years (DALYs) for 333 causes and 84 risk factors with 95% uncertainty intervals (UIs) were computed. Results: Between 1990 and 2016, overall death rates in the United States declined from 745.2 (95% UI, 740.6 to 749.8) per 100 000 persons to 578.0 (95% UI, 569.4 to 587.1) per 100 000 persons. The probability of death among adults aged 20 to 55 years declined in 31 states and Washington, DC from 1990 to 2016. In 2016, Hawaii had the highest life expectancy at birth (81.3 years) and Mississippi had the lowest (74.7 years), a 6.6-year difference. Minnesota had the highest HALE at birth (70.3 years), and West Virginia had the lowest (63.8 years), a 6.5-year difference. The leading causes of DALYs in the United States for 1990 and 2016 were ischemic heart disease and lung cancer, while the third leading cause in 1990 was low back pain, and the third leading cause in 2016 was chronic obstructive pulmonary disease. Opioid use disorders moved from the 11th leading cause of DALYs in 1990 to the 7th leading cause in 2016, representing a 74.5% (95% UI, 42.8% to 93.9%) change. In 2016, each of the following 6 risks individually accounted for more than 5% of risk-attributable DALYs: tobacco consumption, high body mass index (BMI), poor diet, alcohol and drug use, high fasting plasma glucose, and high blood pressure. Across all US states, the top risk factors in terms of attributable DALYs were due to 1 of the 3 following causes: tobacco consumption (32 states), high BMI (10 states), or alcohol and drug use (8 states). Conclusions and Relevance: There are wide differences in the burden of disease at the state level. Specific diseases and risk factors, such as drug use disorders, high BMI, poor diet, high fasting plasma glucose level, and alcohol use disorders are increasing and warrant increased attention. These data can be used to inform national health priorities for research, clinical care, and policy.

Global Skin Disease Morbidity and Mortality: An Update From the Global Burden of Disease Study 2013.

Importance: Disability secondary to skin conditions is substantial worldwide. The Global Burden of Disease Study 2013 includes estimates of global morbidity and mortality due to skin diseases. Objective: To measure the burden of skin diseases worldwide. Data Sources: For nonfatal estimates, data were found by literature search using PubMed and Google Scholar in English and Spanish for years 1980 through 2013 and by accessing administrative data on hospital inpatient and outpatient episodes. Data for fatal estimates were based on vital registration and verbal autopsy data. Study Selection: Skin disease data were extracted from more than 4000 sources including systematic reviews, surveys, population-based disease registries, hospital inpatient data, outpatient data, cohort studies, and autopsy data. Data metrics included incidence, prevalence, remission, duration, severity, deaths, and mortality risk. Data Extraction and Synthesis: Data were extracted by age, time period, case definitions, and other study characteristics. Data points were modeled with Bayesian meta-regression to generate estimates of morbidity and mortality metrics for skin diseases. All estimates were made with 95% uncertainty intervals. Main Outcomes and Measures: Disability-adjusted life years (DALYs), years lived with disability, and years of life lost from 15 skin conditions in 188 countries. Results: Skin conditions contributed 1.79% to the global burden of disease measured in DALYs from 306 diseases and injuries in 2013. Individual skin diseases varied in size from 0.38% of total burden for dermatitis (atopic, contact, and seborrheic dermatitis), 0.29% for acne vulgaris, 0.19% for psoriasis, 0.19% for urticaria, 0.16% for viral skin diseases, 0.15% for fungal skin diseases, 0.07% for scabies, 0.06% for malignant skin melanoma, 0.05% for pyoderma, 0.04% for cellulitis, 0.03% for keratinocyte carcinoma, 0.03% for decubitus ulcer, and 0.01% for alopecia areata. All other skin and subcutaneous diseases composed 0.12% of total DALYs. Conclusions and Relevance: Skin and subcutaneous diseases were the 18th leading cause of global DALYs in Global Burden of Disease 2013. Excluding mortality, skin diseases were the fourth leading cause of disability worldwide.