Ali H. Mokdad

Global burden of diseases, injuries, and risk factors for young people's health during 1990-2013: a systematic analysis for the Global Burden of Disease Study 2013.

BACKGROUND Young peoples health has emerged as a neglected yet pressing issue in global development. Changing patterns of young peoples health have the potential to undermine future population health as well as global economic development unless timely and effective strategies are put into place. We report the past, present, and anticipated burden of disease in young people aged 10-24 years from 1990 to 2013 using data on mortality, disability, injuries, and health risk factors. METHODS The Global Burden of Disease Study 2013 (GBD 2013) includes annual assessments for 188 countries from 1990 to 2013, covering 306 diseases and injuries, 1233 sequelae, and 79 risk factors. We used the comparative risk assessment approach to assess how much of the burden of disease reported in a given year can be attributed to past exposure to a risk. We estimated attributable burden by comparing observed health outcomes with those that would have been observed if an alternative or counterfactual level of exposure had occurred in the past. We applied the same method to previous years to allow comparisons from 1990 to 2013. We cross-tabulated the quantiles of disability-adjusted life-years (DALYs) by quintiles of DALYs annual increase from 1990 to 2013 to show rates of DALYs increase by burden. We used the GBD 2013 hierarchy of causes that organises 306 diseases and injuries into four levels of classification. Level one distinguishes three broad categories: first, communicable, maternal, neonatal, and nutritional disorders; second, non-communicable diseases; and third, injuries. Level two has 21 mutually exclusive and collectively exhaustive categories, level three has 163 categories, and level four has 254 categories. FINDINGS The leading causes of death in 2013 for young people aged 10-14 years were HIV/AIDS, road injuries, and drowning (25·2%), whereas transport injuries were the leading cause of death for ages 15-19 years (14·2%) and 20-24 years (15·6%). Maternal disorders were the highest cause of death for young women aged 20-24 years (17·1%) and the fourth highest for girls aged 15-19 years (11·5%) in 2013. Unsafe sex as a risk factor for DALYs increased from the 13th rank to the second for both sexes aged 15-19 years from 1990 to 2013. Alcohol misuse was the highest risk factor for DALYs (7·0% overall, 10·5% for males, and 2·7% for females) for young people aged 20-24 years, whereas drug use accounted for 2·7% (3·3% for males and 2·0% for females). The contribution of risk factors varied between and within countries. For example, for ages 20-24 years, drug use was highest in Qatar and accounted for 4·9% of DALYs, followed by 4·8% in the United Arab Emirates, whereas alcohol use was highest in Russia and accounted for 21·4%, followed by 21·0% in Belarus. Alcohol accounted for 9·0% (ranging from 4·2% in Hong Kong to 11·3% in Shandong) in China and 11·6% (ranging from 10·1% in Aguascalientes to 14·9% in Chihuahua) of DALYs in Mexico for young people aged 20-24 years. Alcohol and drug use in those aged 10-24 years had an annual rate of change of >1·0% from 1990 to 2013 and accounted for more than 3·1% of DALYs. INTERPRETATION Our findings call for increased efforts to improve health and reduce the burden of disease and risks for diseases in later life in young people. Moreover, because of the large variations between countries in risks and burden, a global approach to improve health during this important period of life will fail unless the particularities of each country are taken into account. Finally, our results call for a strategy to overcome the financial and technical barriers to adequately capture young peoples health risk factors and their determinants in health information systems. FUNDING Bill & Melinda Gates Foundation.

Recent Trends in Waist Circumference and Waist-Height Ratio Among US Children and Adolescents

OBJECTIVES. Abdominal obesity may be a better predictor than overall obesity for the risk of cardiovascular disease and type 2 diabetes. Waist circumference and waist-height ratio are 2 simple, yet effective, surrogate measures of abdominal obesity. We sought to examine the recent trends in mean waist circumference and waist-height ratio and prevalence of abdominal obesity among children and adolescents aged 2 to 19 years in the United States. METHODS. Representative samples of the civilian, noninstitutionalized US population from the National Health and Nutrition Examination Survey conducted during 4 time periods, 1988–1994 (ie, National Health and Nutrition Examination Survey III), 1999–2000, 2001–2002, and 2003–2004, were examined to estimate the mean waist circumference and waist-height ratio of boys and girls in 4 different age groups. Data from the 3 most recent National Health and Nutrition Examination Surveys were combined to establish a National Health and Nutrition Examination Survey 1999–2004 category. RESULTS. Categorized by age group, the unadjusted mean waist circumference for boys increased between National Health and Nutrition Examination Survey III and National Health and Nutrition Examination Survey 1999–2004 from 50.7 cm (aged 2–5 years), 61.9 cm (aged 6–11 years), 76.8 cm (aged 12–17 years), and 81.3 cm (aged 18–19 years) to 51.9, 64.5, 79.8, and 86.6 cm, respectively. During the same time periods and within the same age groups, the unadjusted mean waist circumference for girls increased from 51.0, 61.7, 75.0, and 77.7 cm to 51.8, 64.7, 78.9, and 83.9 cm, respectively. The relative change in waist-height ratio was similar to waist circumference at each age group for both boys and girls. Using the 90th percentile values of waist circumference for gender and age, the prevalence of abdominal obesity increased by 65.4% (from 10.5% to 17.4%) and 69.4% (from 10.5% to 17.8%) for boys and girls, respectively. CONCLUSIONS. Mean waist circumference and waist-height ratio and the prevalence of abdominal obesity among US children and adolescents greatly increased between 1988–1994 and 1999–2004.

The global burden of viral hepatitis from 1990 to 2013: findings from the Global Burden of Disease Study 2013

BACKGROUND With recent improvements in vaccines and treatments against viral hepatitis, an improved understanding of the burden of viral hepatitis is needed to inform global intervention strategies. We used data from the Global Burden of Disease (GBD) Study to estimate morbidity and mortality for acute viral hepatitis, and for cirrhosis and liver cancer caused by viral hepatitis, by age, sex, and country from 1990 to 2013. METHODS We estimated mortality using natural history models for acute hepatitis infections and GBDs cause-of-death ensemble model for cirrhosis and liver cancer. We used meta-regression to estimate total cirrhosis and total liver cancer prevalence, as well as the proportion of cirrhosis and liver cancer attributable to each cause. We then estimated cause-specific prevalence as the product of the total prevalence and the proportion attributable to a specific cause. Disability-adjusted life-years (DALYs) were calculated as the sum of years of life lost (YLLs) and years lived with disability (YLDs). FINDINGS Between 1990 and 2013, global viral hepatitis deaths increased from 0·89 million (95% uncertainty interval [UI] 0·86-0·94) to 1·45 million (1·38-1·54); YLLs from 31·0 million (29·6-32·6) to 41·6 million (39·1-44·7); YLDs from 0·65 million (0·45-0·89) to 0·87 million (0·61-1·18); and DALYs from 31·7 million (30·2-33·3) to 42·5 million (39·9-45·6). In 2013, viral hepatitis was the seventh (95% UI seventh to eighth) leading cause of death worldwide, compared with tenth (tenth to 12th) in 1990. INTERPRETATION Viral hepatitis is a leading cause of death and disability worldwide. Unlike most communicable diseases, the absolute burden and relative rank of viral hepatitis increased between 1990 and 2013. The enormous health loss attributable to viral hepatitis, and the availability of effective vaccines and treatments, suggests an important opportunity to improve public health. FUNDING Bill & Melinda Gates Foundation.

Prevalence of Pre-Diabetes and Its Association With Clustering of Cardiometabolic Risk Factors and Hyperinsulinemia Among U.S. Adolescents National Health and Nutrition Examination Survey 2005–2006

OBJECTIVE—Impaired fasting glucose (IFG) and/or impaired glucose tolerance (IGT) are considered to constitute “pre-diabetes.” We estimated the prevalence of IFG, IGT, and pre-diabetes among U.S. adolescents using data from a nationally representative sample. RESEARCH DESIGN AND METHODS—We analyzed data from participants aged 12–19 years in the National Health and Nutrition Examination Survey 2005–2006. We used fasting plasma glucose and 2-h glucose during an oral glucose tolerance test to assess the prevalence of IFG, IGT, and pre-diabetes and used the log-binomial model to estimate the prevalence ratios (PRs) and 95% CIs. RESULTS—The unadjusted prevalences of IFG, IGT, and pre-diabetes were 13.1, 3.4, and 16.1%, respectively. Boys had a 2.4-fold higher prevalence of pre-diabetes than girls (95% CI 1.3–4.3). Non-Hispanic blacks had a lower rate than non-Hispanic whites (PR 0.6, 95% CI 0.4–0.9). Adolescents aged 16–19 years had a lower rate than those aged 12–15 years (0.6, 0.4–0.9). Overweight adolescents had a 2.6-fold higher rate than those with normal weight (1.3–5.1). Adolescents with two or more cardiometabolic risk factors had a 2.7-fold higher rate than those with none (1.5–4.8). Adolescents with hyperinsulinemia had a fourfold higher prevalence (2.2–7.4) than those without. Neither overweight nor number of cardiometabolic risk factors was significantly associated with pre-diabetes after adjustment for hyperinsulinemia. CONCLUSIONS—Pre-diabetes was highly prevalent among adolescents. Hyperinsulinemia was independently associated with pre-diabetes and may account for the association of overweight and clustering of cardiometabolic risk factors with pre-diabetes.

Health of the world's adolescents: a synthesis of internationally comparable data

Adolescence and young adulthood offer opportunities for health gains both through prevention and early clinical intervention. Yet development of health information systems to support this work has been weak and so far lagged behind those for early childhood and adulthood. With falls in the number of deaths in earlier childhood in many countries and a shifting emphasis to non-communicable disease risks, injuries, and mental health, there are good reasons to assess the present sources of health information for young people. We derive indicators from the conceptual framework for the Series on adolescent health and assess the available data to describe them. We selected indicators for their public health importance and their coverage of major health outcomes in young people, health risk behaviours and states, risk and protective factors, social role transitions relevant to health, and health service inputs. We then specify definitions that maximise international comparability. Even with this optimisation of data usage, only seven of the 25 indicators, covered at least 50% of the worlds adolescents. The worst adolescent health profiles are in sub-Saharan Africa, with persisting high mortality from maternal and infectious causes. Risks for non-communicable diseases are spreading rapidly, with the highest rates of tobacco use and overweight, and lowest rates of physical activity, predominantly in adolescents living in low-income and middle-income countries. Even for present global health agendas, such as HIV infection and maternal mortality, data sources are incomplete for adolescents. We propose a series of steps that include better coordination and use of data collected across countries, greater harmonisation of school-based surveys, further development of strategies for socially marginalised youth, targeted research into the validity and use of these health indicators, advocating for adolescent-health information within new global health initiatives, and a recommendation that every country produce a regular report on the health of its adolescents.

The association between fruit and vegetable intake and chronic disease risk factors.

Understanding the associations between fruit and vegetable intake and other health behaviors is important for properly interpreting the rapidly growing number of studies that link low intakes of fruits and vegetables to the risk of cancer and cardiovascular disease. To examine the association between fruit and vegetable intake and behavioral risk factors for chronic diseases, we analyzed data from a population-based behavioral risk factor survey. Data were collected in 1990 from 21,892 adults in 16 states by a random-digit-dial telephone survey. Respondents answered questions about behaviors related to chronic disease risk, including their frequency of intake of fruits and vegetables, using a six-item questionnaire. Consumption of fruits and vegetables was lowest among those who also reported that they were sedentary, heavy smokers, heavy drinkers, or had never had their blood cholesterol checked. Because fruit and vegetable intake covaries with several other chronic disease risk factors, it is important to account for possible confounding between fruit and vegetable intake and other behaviors in etiologic studies of the risk of cancer and cardiovascular disease.

Liver cirrhosis mortality in 187 countries between 1980 and 2010: a systematic analysis

BackgroundLiver cirrhosis is a major yet largely preventable and underappreciated cause of global health loss. Variations in cirrhosis mortality at the country level reflect differences in prevalence of risk factors such as alcohol use and hepatitis B and C infection. We estimated annual age-specific mortality from liver cirrhosis in 187 countries between 1980 and 2010.MethodsWe systematically collected vital registration and verbal autopsy data on liver cirrhosis mortality for the period 1980 to 2010. We corrected for misclassification of deaths, which included deaths attributed to improbable or nonfatal causes. We used ensemble models to estimate liver cirrhosis mortality with uncertainty by age, sex, country and year. We used out-of-sample predictive validity to select the optimal model.ResultsGlobal liver cirrhosis deaths increased from around 676,000 (95% uncertainty interval: 452,863 to 1,004,530) in 1980 to over 1 million (1,029,042; 670,216 to 1,554,530) in 2010 (about 2% of the global total). Over the same period, the age-standardized cirrhosis mortality rate decreased by 22%. This was largely driven by decreasing cirrhosis mortality rates in China, the US and countries in Western Europe. In 2010, Egypt, followed by Moldova, had the highest age-standardized cirrhosis mortality rates, 72.7 and 71.2 deaths per 100,000, respectively, while Iceland had the lowest. In Egypt, almost one-fifth (18.1%) of all deaths in males 45- to 54-years old were due to liver cirrhosis. Liver cirrhosis mortality in Mexico is the highest in Latin America. In France and Italy, liver cirrhosis mortality fell by 50% to 60%; conversely, in the United Kingdom, mortality increased by about one-third. Mortality from liver cirrhosis was also comparatively high in Central Asia countries, particularly Mongolia, Uzbekistan and Kyrgyzstan, and in parts of sub-Saharan Africa, notably Gabon.ConclusionsLiver cirrhosis is a significant cause of global health burden, with more than one million deaths in 2010. Our study identifies areas with high and/or rapidly increasing mortality where preventive measures to control and reduce liver cirrhosis risk factors should be urgently strengthened.Please see related commentary: http://www.biomedcentral.com/1741-7015/12/159/abstract.

The validity of self-reports of past body weights by U.S. adults.

Past weight or patterns of weight change may be more important to chronic disease risk than current weight. Self-reports, however, are often the only source of information about past body weight. To date, very few studies have examined factors affecting the validity of self-reported past body weight. We examined the validity of self-reported past body weights of 1,931 U.S. adults who were participants in the First National Health and Nutrition Examination Survey (1971–1975) and were interviewed again in the National Health and Nutrition Examination Survey I Epidemiologic Follow-up Study (1982–1984). We compared the body weight measured during the initial examination (1971–1975) with the recalled 1971–1975 body weight reported during the follow-up interview (1982–1984). Recalled past weight was strongly correlated with previously measured weight (r = 0.73 for men, and r = 0.74 for women). Men overestimated their past body weight, whereas women underestimated their past weight. Although 39% of men and 41% of women estimated their past weight within 5 pounds, approximately 17% of women and 10% of men underestimated their past weight more than 15 pounds. Accuracy of reporting was influenced by sex, race, current body mass index, and the amount of weight gained over the 10 years following the initial examination. These factors should be considered when using recalled weight in epidemiologic studies.

Prevalence of depression among U.S. adults with diabetes: findings from the 2006 behavioral risk factor surveillance system.

OBJECTIVE—To estimate the prevalence rate of depression among adults with diabetes using a large population-based sample in the U.S. RESEARCH DESIGN AND METHODS—Data from the 2006 Behavioral Risk Factor Surveillance System, a standardized telephone survey among U.S. adults aged ≥18 years, were analyzed (n = 18,814). The Patient Health Questionnaire diagnostic algorithm was used to identify major depression. RESULTS—The age-adjusted prevalence rate of major depression was 8.3% (95% CI 7.3–9.3), ranging from a low of 2.0% in Connecticut to a high of 28.8% in Alaska. There were 25-fold differences in the rate among racial/ethnic subgroups (lowest, 1.1% among Asians; highest, 27.8% among American Indians/Alaska Natives). People with type 2 diabetes who were currently using insulin had a higher rate than people with type 1 diabetes (P = 0.0009) and those with type 2 diabetes who were currently not using insulin (P = 0.01). CONCLUSIONS—Major depression was highly prevalent among people with diabetes; the prevalence rate varied greatly by demographic characteristics and diabetes types.

Trends in fruit and vegetable consumption among adults in 16 US states: behavioral risk factor surveillance system, 1990-1996.

OBJECTIVES This study examined trends in fruit and vegetable consumption among adults in 16 US states. METHODS Data from telephone surveys were used to stratify respondents by sociodemographic and health-related characteristics. RESULTS The proportion of adults who consumed fruits and vegetables at least 5 times daily was 19%, 22%, and 23% in 1990, 1994, and 1996, respectively. While the proportion increased among those with active leisure-time physical activities and normal weight, it remained almost the same among inactive people and dropped among the obese. CONCLUSIONS Progress in fruit and vegetable intake from 1990 to 1994 was encouraging, but it changed little between 1994 and 1996.