National Burden Of Disease Study Research Articles

Establishing disease models for the Belgian national burden of disease study: challenges and perspectives

Abstract The Belgian national burden of disease study (BeBOD) was launched in 2022, and currently provides disease burden estimates for 38 key diseases. The calculation of the non-fatal component of the disease burden, the Years Lived with Disability (YLD), follows a stepwise approach that aims to establish priority outcomes; quantify prevalence “best estimates”; establish disease models; and perform expert evaluation of methods and results. The disease models visualize the relationship between the different health states associated with a given outcome. Health states include the different acute and chronic stages of the outcome (including complications), which may be stratified in different severity levels (e.g., mild, moderate, severe). Disease models used in burden of disease studies primarily aim to document the considered health states, and do not aim at a representation of the complete clinical picture of the condition. The disease models instead help in understanding how the number of cases for each health state is calculated. Models typically start with one “parent node”, which contains all cases. This parent node then gives rise to multiple “child nodes”, with the terminal child nodes representing the individual health states. In BeBOD, disease models and severity distributions are adapted from the Global Burden of Disease (GBD) study, and complemented with local data where possible. This process ensures consistency with available disability weights, while still allowing for local data to feed into the calculations. In this presentation, we will demonstrate the BeBOD process for establishing disease models based on a number of archetypical examples, which represent varying challenges linked to disease model complexity, clarity and completeness of the GBD disease model documentation, and availability of local data. Future perspectives will be discussed, including the improved leveraging of local clinical data, and the implementation of tailored active data collection.

Reception of health data using the Australian Burden of Disease study as an example

Abstract Background Health data, especially on Burden of Disease (BoD), are vital for evidence-based health promotion and effective dissemination is crucial due to resource intensiveness. Germany’s national BoD study is currently transitioning to permanence. Analysing the Australian Institute of Health and Welfare’s (AIHW) well-established collaboration with stakeholders and their reception of health data at national and regional level offers insights for improved knowledge translation. Methods To follow the path of stakeholder engagement, this 3-month project involved scientific exchanges with the AIHW and Department of Health, Western Australia. It compiled communication strategy examples and documents stating examples of BoD data use. A quantitative online survey accompanied by a series of 18 qualitative 45-minute interviews was conducted. The survey implemented via Swift Digital has been running for 20+ days. Interview partners originated from the fields of health research, politics, planning and advocacy for patients or population groups. Results were analysed, illustrated digitally as a booklet and refined in a participatory workshop. Results Communication strategies such as embargoed press and stakeholder releases as well as regular online formats were identified. The survey and interviews displayed the required technical and content-detail level from key facts to raw data and visualisation needs. Noteworthy are the demand to link data to economic aspects like disease expenditure, trends and future scenarios. It elucidated how diverse target groups utilize data to place disease significance and preventive public health measures, aiding dissemination. Alongside, it shows examples of knowledge translation by emphasizing impact over indicators when targeting communities. Conclusions Prioritizing target group identification and employing tailored communication strategies regarding data format and detail level are essential when utilizing new data. Key messages • Analyzing a well-established collaboration with stakeholders offers insights for improved knowledge translation and reveals leveraging engagement strategies for others. • Understanding stakeholder needs is essential for promoting broader health data use in policy and practice, fostering evidence-based decision-making, and enhancing public health outcomes.

Burden of inflammatory bowel disease in Belgium, 2020

Abstract Inflammatory bowel disease (IBD) comprises digestive disorders resulting from non-infectious inflammation of the colon and gastrointestinal tract. With its global prevalence on the rise, IBD poses significant challenges to healthcare systems. There is a need for more accurate disease burden estimates to guide decision-making processes within the health sector. As a part of the Belgian national burden of disease study (BeBOD), this study aims to estimate the burden of IBD in Belgium based on locally available data. We estimated the Belgian IBD burden in 2020 in terms of mortality, prevalence, years of life lost (YLLs) due to premature death, years lived with disability (YLDs), and disability-adjusted life years (DALYs). As there is no single comprehensive data source on prevalence of IBD in Belgium, a critical appraisal of existing local and national data sources was conducted. Prevalence data were combined with disability weights to yield YLDs. YLLs were calculated using the most recent Global Burden of Disease (GBD) 2019 reference life table and the number of deaths caused by non-infective IBD (ICD-10 K50-52). Cause of death data were extracted from Statbel, the Belgian statistical office. The best available data source to estimate the IBD prevalence in Belgium was a widespread network of general practitioners. The prevalence of IBD was 1.5% in 2020. The prevalence-based YLD for IBD was 220 YLDs per 100 000, while the YLL rate was 11.5 per 100 000. We estimated 26 276 DALYs caused by IBD in 2020. Of the total DALYs caused by IBD, 5% were due to YLLs and 95% were due to YLDs. Our burden estimates for IBD in Belgium were however higher than those of the GBD study. IBD imposes a low fatal burden, whereas the burden of morbidity is more prominent. Our findings could be useful for policy makers to justify and prioritize resource allocation. Integrating the current research in BeBOD will allow monitoring the burden of IBD over time. Key messages • Inflammatory bowel disease is characterized by a substantial non-fatal burden due to chronic relapsing and persistent symptoms. • National inflammatory bowel disease burden estimates are useful to guide decision-making within the health sector.

Burden of disease due to road traffic noise in Flanders, Belgium

Abstract This study estimates the disease burden of ischemic heart disease (IHD), stroke and diabetes mellitus attributable to road traffic noise in the Flemish Region (Belgium) for the year 2020, expressed in disability-adjusted life years (DALYs). The research proposes an approach to stratify population exposure to noise according to age and sex, which allows to examine internal differences in noise burden related to both varying risk and baseline burden. Stratification of population exposure to noise is achieved by (1) linking modelled noise exposure to age- and sex-stratified population data at small area-level, (2) dividing the prevalence in each exposure class proportionally over the strata, and (3) aggregating the small areas to a Flemish total per stratum. Annual day-evening-night level exposure is translated into the fraction of attributable burden relying on relative risks (RR) from the WHO’s Environmental Noise Guidelines and more recent studies. Baseline burden for the three outcomes is sourced from the Belgian National Burden of Disease Study. The lower and upper bound of the RR’s 95% confidence interval (CI) are used to calculate the uncertainty range on the burden estimates. The total noise DALYs estimated are 1092 (95% CI: 135, 2061) for IHD, 761 (379, 1017) for stroke, and 671 (486, 918) for diabetes. Noise burden rates rise steeply with age for all outcomes, although the wide CIs on the IHD estimates prevent to ascertain a significant trend. The IHD burden is twice as high in men as in women, while both sexes are almost equal for the other outcomes. The variations between age and sex groups are largely explained by differences in baseline burden, as exposure is fairly constant across strata. This study estimates age- and sex-stratified disease burden attributable to noise traffic in Flanders, Belgium. As differential exposure between the population subgroups is limited, any variation in noise DALYs is mainly related to stratum-specific baseline burden. Key messages • Road traffic noise is responsible for hundreds of healthy life years lost in Flanders, Belgium. • The noise burden for stroke and diabetes rises sharply with age, and the burden for ischemic heart disease is twice as high in men as in women.

The burden of psoriasis in Belgium, 2021

Abstract Psoriasis is a common, chronic, inflammatory skin disease with a great impact on healthcare systems. Given the limitations of the currently available burden estimates, estimates of the Belgian national burden of disease study are necessary in order to guide decision-making processes within the health sector. According to the Global Psoriasis Atlas, the prevalence of psoriasis is rising globally. The current study aims to estimate the burden of psoriasis in Belgium using national data. As there is no single comprehensive data source on prevalence of psoriasis in Belgium, a critical appraisal of existing local and national data sources was conducted. We estimated the non-fatal psoriasis burden in terms of years lived with disability (YLD). Estimated prevalence data were combined with disability weights to yield YLDs imposed by psoriasis. Mortality attributable to psoriasis was assumed to be zero, in line with the Global Burden of Disease study (GBD) 2019. We assessed three data sources containing information on existing cases with psoriasis in Belgium. Based on qualitative and quantitative appraisal, a widespread network of general practitioners was identified as the best available national data source. In 2021, the prevalence of psoriasis in Belgium was 2.1%, leading to 13084 DALYs (113 DALYs per 100 000). The burden of psoriasis was in line with national disease burden estimates for bipolar disorder, multiple myeloma, and hearing loss. Our prevalence, YLD, and DALY estimates for psoriasis in Belgium were however lower than those of the GBD study. Psoriasis imposes a non-negligible burden on population health in Belgium, despite it not being a cause of death. Along progression in psoriasis management, objective evaluation of psoriasis burden is critical to track the trends at the population level. Key messages • Psoriasis is a common skin disease with a relatively high morbidity burden. • Information on psoriasis prevalence and burden are crucial for disease management and appropriate health-care planning.

Methodological insights into severity distribution of non-fatal cancer burden in Belgium using a microsimulation model (2004-2019)

Abstract This study leverages a registry-based microsimulation model to analyze the non-fatal burden of cancer in Belgium from 2004 to 2019, emphasizing the methodology for severity distribution. Utilizing incidence- and prevalence-based approaches, we estimated Years Lived with Disability (YLD) through detailed national cancer registry data coupled with tailored disease models. The microsimulation model employed enabled nuanced translation of cancer incidence into prevalence estimates, incorporating the longitudinal impacts of disease severity influenced by treatment. Methodologically, the model integrated expert elicitation to adjust for treatment-related disabilities, such as surgical aftereffects, enhancing the accuracy of disability weight assignment across different cancer stages. This approach allowed for a dynamic assessment of disease burden, reflecting real-world complexities of cancer prognosis and treatment pathways. Significant findings include a substantial increase in the age-standardized non-fatal burden for non-melanoma skin cancer, highlighting the model’s capability to detect shifts in disease impact over time. By focusing on the microsimulation’s capacity to delineate severity distributions within the cancer burden landscape, this analysis underscores the model’s utility in refining health policy decisions and resource allocation. Ultimately, this study presents a robust framework for national burden of disease studies, facilitating detailed evaluations of health interventions and their longitudinal effectiveness.

Estimating the economic burden of mental and substance use disorders in Belgium

Abstract Mental and substance use disorders are the leading cause of disease burden (disability-adjusted life years, DALYs) in Belgium. Strong mental health policies are needed to reduce the burden, taking into account effectiveness and cost-effectiveness of possible interventions. Next to providing an overview of the economic burden of mental health conditions (what is), routine cost-of-illness studies also serve as a source of information for modelling the cost-effectiveness of policies and interventions to improve the mental health of populations (what could be). In the context of an extension of the Belgian Health Status Report and the Belgian National Burden of Disease Study, we calculated the direct medical costs of a range of health conditions, including mental health conditions such as depression. We used self-reported diagnostic data from the Belgian health Interview Survey linked with claims data to calculate the incremental costs attributable to mental health disorders with g-computation. We correct for confounders such as age and sex, and also look at uncertainty brought about by the data source and modelling. This presentation aims to share the experience of calculating the economic burden of mental ill-health in the context of a routine cost-of-illness study. We will present the results of the study and discuss alternative ways in which the costs of common mental health conditions such as depression could be estimated, for example based entirely on claims data using pharmaceutical cost groups.

Trends of Gaps Between Health-Adjusted Life Expectancy and Life Expectancy at the Regional Level in Korea Using a Group-Based Multi-Trajectory Modeling Approach (2008-2019).

Health-adjusted life expectancy (HALE) is an indicator of the average lifespan in good health. Through this study, we aimed to identify regional disparities in the gap between HALE and life expectancy, considering the trends that have changed over time in Korea. We employed a group-based multi-trajectory modeling approach to capture trends in the gap between HALE and life expectancy at the regional level from 2008 to 2019. HALE was calculated using incidence-based "years lived with disability." This methodology was also employed in the Korean National Burden of Disease Study. Based on five different information criteria, the most fitted number of trajectory groups was seven, with at least 11 regions in each group. Among the seven groups, one had an exceptionally large gap between HALE and life expectancy compared to that of the others. This group was assigned to 17 regions, of which six were metropolitan cities. Based on the results of this study, we identified regions in which health levels have deteriorated over time, particularly within specific areas of metropolitan cities. These findings can be used to design comprehensive policy interventions for community health promotion and urban regeneration projects in the future.

Investigating the Epidemiological Trend and Estimating the Burden of COVID-19 in the Military Population of the Islamic Republic of Iran

Background: The Burden of Disease study provides a comprehensive picture of mortality and disability across countries, time periods, age groups, and genders. Objectives: This study was conducted to determine the epidemiological trend and estimate the burden of COVID-19 in the military population of Iran. Methods: This cross-sectional study used the methods by the World Health Organization for the national burden of disease studies to estimate the years of life lost due to premature death and burden of disability (YLD), years of life lost from mortality (YLL), years of life lost due to disability diseases, and the total burden of death and disability in terms of disability-adjusted life years (DALY). The information to calculate the desired indicators for COVID-19 in the military population of Iran, including the number of deaths, the number of hospitalizations, and the costs of hospitalization and treatment of patients, was obtained from the insurance organization of the armed forces. Excel software version 2017 is used to calculate 3 indicators. Results: The total DALY for COVID-19 in the Iranian military population during the three-year study period was calculated to be 162,429 years, which is a significant figure. The disease burden showed an increasing trend in the study years and reached its peak in 2021, which aligns with the overall disease situation in the country. In general, the burden of disease was higher in men than in women. Conclusions: The impact of COVID-19 on the military and its economic burden was substantial in the studied areas. Therefore, it is crucial to undertake careful planning in addressing these issues. Using economic burden studies and examining their dimensions provides policymakers with sufficient evidence to allocate financial resources to vital sectors and adopt appropriate policies in critical situations.

Risk ranking of foodborne diseases in Denmark: Reflections on a national burden of disease study

National burden of foodborne disease (FBD) studies are useful for risk ranking and identifying priorities for food safety resource allocation. FBD are caused by microbiological and chemical hazards, which have different incidence and mortality, and lead to health-outcomes varying in severity and duration. Due to their different origins and characteristics, distinct prevention strategies can be implemented. We present the Danish initiative to estimate the burden of FBD caused by pathogens and chemicals. We describe the methodological approaches and data used, present an overview of results for the reference year 2019, and discuss lessons learned throughout more than seven years of the project. Our estimates show that the leading causes of FBD in Denmark include both pathogens and chemicals, suggesting that food safety strategies should be diversified to tackle different issues. The experiences with this national study are useful for other countries planning to implement a burden of FBD study.

Years Lived with Disability due to COVID-19 in the capital of Serbia in 2020 and 2021

Abstract Background Valid estimates of the national disease burden often lack during crises. They need to be improved to help assess the effectiveness and efficiency of the national public health system. To determine the magnitude of acute COVID-19 in Belgrade in 2020 and 2021, we estimated the total, age and sex-disaggregated Years Lived with Disability (YLD). Methods YLD and YLD/100,000 population due to acute COVID-19 were calculated for Belgrade (Serbia) in 2020 (March 6 - December 31) and 2021 (January 1 - December 31) within the EU COST Action 18218 and the BoCO-19 study. The City Institute of Public Health Belgrade provided surveillance numbers of cases of ICD-X: U07.1 and U07.2 (unknown age cases were proportionally redistributed) and population estimates. Severity weights and length of the disease were taken from the German National Burden of Disease study. Results In 2020, 33,842 acute COVID-19 cases (50.04% were men) had 73.0 YLD (men: 40.6 YLD or 5.1 YLD /100,000; women: 32.4 YLD or 3.6 YLD/100,000). In 2021, 65,020 COVID-19 cases (54.5% were women) had 130.3 YLD (men: 65.1 YLD or 8.2 YLD /100,000; women: 65.2 YLD or 7.3 YLD/100,000). Mild cases were more often among men 10-19 years and women 35-44 years. Moderate cases were more often among persons 35-44 years. Critical cases were more often among the men. More YLD were estimated for severe cases among women in 2021 than in 2020. Conclusions In Belgrade, the YLD burden of acute COVID-19 in 2021 was almost double that of 2020. Women had more often severe forms of acute COVID-19 and more YLD in 2021 than in 2020. Men often had moderate and critical cases of acute COVID-19 and higher YLD rates than women. The COVID-19 pandemic demonstrates the importance of having disease burden metrics to help contextually assess the health system's response to crises. Belgrade-level estimates can also be used for national estimates because of the same case definitions, treatment protocols, and data collection methods. Key messages • The YLD burden of the COVID-19 pandemic in 2021 was almost double that of 2020 for population of Belgrade. • In 2020, higher YLD had men due to critical cases, in 2020, women due to severe cases in 2021 indicating greater exposure of men and greater vulnerability of women.

Global, regional, and national burden of disease study of atrial fibrillation/flutter, 1990–2019: results from a global burden of disease study, 2019

BackgroundData from the Global Burden of Disease, Injury, and Risk Factor Study 2019 (GBD 2019) was used to assess the burden and change in prevalence, incidence, deaths, disability-adjusted life years, and risk factors for atrial fibrillation/flutter in 204 countries and territories between 1990 and 2019.MethodsIncidence, prevalence, deaths, disability-adjusted life years (DALYs), and their age-standardized rates of AF/AFL were analyzed by age, sex, socio-demographic index (SDI), and human development index (HDI) using the Global Burden of Disease study 2019 (GBD2019) results，and risk factors for AF/AFL (mainly high systolic blood pressure, high body-mass index, alcohol use, smoking and diet high in sodium) were differentially analyzed.ResultsThere are 59.70 million (95% uncertainty interval (UI) 45.73–75.29 million) AF/AFL patients worldwide in 2019, with 4.72 million (95% uncertainty interval (UI) 3.64–5.96 million) new cases and 0.315 million deaths (95% uncertainty interval (UI) 0.268–0.361 million) and 8.39 million disability-adjusted years (95% uncertainty interval (UI) 6.69–10.54 million). The highest risk factor for deaths, DALYs attributable to AF/AFL in 2019 was high systolic blood pressure, high body-mass index, alcohol use, smoking, and diet high in sodium. It is estimated that between 2030 and 2034, the total incidence of male AF/ AFL will be 16.08 million, and the total number of deaths will be 1.01 million. For females, the total number of incidence is 16.85 million, and the total number of deaths is 1.49 million.ConclusionsAF/AFL remains a major global public health problem, although the ASR of prevalence, incidence, and DALY at the worldwide level showed a decreasing trend from 1990 to 2019(the ASR of deaths increased slightly). However, the unfavorable trend observed in this study in countries with lower SDI suggests that current prevention and treatment strategies should be reoriented. Some countries should develop more targeted and specific strategies to prevent the increase of AF/AFL.

9.Q. Skills building seminar: Redistribution of ill-defined deaths: a methodological conundrum

Abstract Today, several countries are conducting national burden of disease (BOD) studies, calculating Disability-Adjusted Life Years (DALYs) for a variety of diseases, injuries and risk factors. The DALY metric is composed of a morbidity component, the Years Lived with Disability (YLDs), and a mortality component, the Years of Life Lost (YLLs). The calculation of YLLs typically starts from national cause of death data, which are coded using the International Statistical Classification of Diseases and Related Health Problems (ICD). National BOD studies however often follow (a modified version of) the cause hierarchy of the Global Burden of Disease (GBD) study, which applies coarser categories, and does not contain unknown or ill-defined causes. This implies that not all ICD codes can be mapped to one specific BOD cause, giving rise to so-called “ill-defined” or “garbage” codes. To include all deaths in a national BOD study, it is therefore necessary to redistribute the ill-defined deaths to specific BOD causes. Several methodological approaches exist for redistribution of ill-defined deaths, ranging from the use of fixed redistribution proportions to advanced redistribution algorithms based on multiple cause of death data. The choice of the methodology needs to depend on the nature of the available cause of death data, and as a consequence, methodologies are typically tailored to the specific data at hand. The absence of a single best methodology, and the methodological heterogeneity across applications, has made redistribution of ill-defined deaths into a methodological conundrum. This skills building workshop will present the redistribution methods applied in different national burden of disease studies, including a discussion of their strengths and weaknesses. By providing a step-by-step presentation of how the methods have been applied, attendees will gain unique insights in the different redistribution methods currently applied. Key messages • Redistribution of ill-defined deaths is an essential part of national burden of disease studies, but is methodologically challenging. • Attendees will receive an overview of the redistribution methods applied in different national burden of disease studies, including a discussion of their strengths and weaknesses.

Conducting national burden of disease studies and knowledge translation in eight small European states: challenges and opportunities

BackgroundSeveral countries across Europe are engaging in burden of disease (BoD) studies. This article aims to understand the experiences of eight small European states in relation to their research opportunities and challenges in conducting national BoD studies and in knowledge translation of research outputs to policy-making.MethodsCountries participating in the study were those outlined by the WHO/Europe Small Countries Initiative and members of the Cooperation in Science and Technology (COST) Action CA18218 European Burden of Disease Network. A set of key questions targeting the research landscape were distributed to these members. WHO’s framework approach for research development capacities was applied to gain a comprehensive understanding of shortages in relation to national BoD studies in order to help strengthen health research capacities in the small states of Europe.ResultsMost small states lack the resources and expertise to conduct BoD studies, but nationally representative data are relatively accessible. Public health officials and researchers tend to have a close-knit relationship with the governing body and policy-makers. The major challenge faced by small states is in knowledge generation and transfer rather than knowledge translation. Nevertheless, some policy-makers fail to make adequate use of knowledge translation.ConclusionsSmall states, if equipped with adequate resources, may have the capacity to conduct national BoD studies. This work can serve as a model for identifying current gaps and opportunities in each of the eight small European countries, as well as a guide for translating country BoD study results into health policy.

6.Q. Skills building seminar: Integrating social inequalities in the burden of disease framework

Abstract Driven by the influential Global Burden of Disease (GBD) study, the burden of disease (BOD) approach has gained wide interest at national and international level to quantify the state of health and health inequalities. Central to the BOD approach is the Disability-Adjusted Life Year (DALY) metric, which quantifies the health impact of diseases, injuries and risk factors as the number of healthy life years lost compared to a counterfactual scenario of perfect health all life long. The BOD approach offers a valuable platform to quantify social inequalities in health, i.e., differences in health status by socioeconomic and sociodemographic characteristics. This is highly relevant, as health inequalities penalising socially disadvantaged groups are one of the most consistent, and persistent, findings in epidemiology, for almost every health outcome and socioeconomic indicator. Monitoring social inequalities in health is therefore a key priority for national health authorities. There are different ways by which social inequalities can be integrated in the BOD framework, but all come with important data challenges. Individual-level stratification is a common approach for quantifying inequalities by age and sex, but is more challenging for other sociodemographic and socioeconomic indicators. Area-level stratification allows for ecological analyses between BOD estimates and indices of social deprivation. Social inequalities can also be assessed using comparative risk assessment, by which the relative risk for adverse health outcomes in function of social position is to be quantified. This skills building workshop will present the methods that have been applied in different national burden of disease studies to include social inequalities, including a discussion of their strengths and weaknesses. By providing a step-by-step presentation of how the methods have been applied, attendees will gain unique insights in the different ways by which social inequalities can be integrated in the BOD framework. Key messages • The burden of disease framework offers a valuable platform to quantify and monitor social inequalities in health, which is a key priority for health authorities. • Attendees will receive an overview of the different ways by which social inequalities can be integrated in the burden of disease framework, including a discussion of their strengths and weaknesses.

Estimating the changing burden of disease attributable to high body mass index in South Africa for 2000, 2006 and 2012.

A high body mass index (BMI) is associated with several cardiovascular diseases, diabetes and chronic kidney disease, cancers, and other selected health conditions. To quantify the deaths and disability-adjusted life years (DALYs) attributed to high BMI in persons aged ≥20 years in South Africa (SA) for 2000, 2006 and 2012. The comparative risk assessment (CRA) methodology was followed. Meta-regressions of the BMI mean and standard deviation from nine national surveys spanning 1998 - 2017 were conducted to provide estimates by age and sex for adults aged ≥20 years. Population attributable fractions were calculated for selected health outcomes using relative risks identified by the Global Burden of Disease Study (2017), and applied to deaths and DALY estimates from the second South African National Burden of Disease Study to estimate the burden attributed to high BMI in a customised Microsoft Excel workbook. Monte Carlo simulation-modelling techniques were used for the uncertainty analysis. BMI was assumed to follow a log-normal distribution, and the theoretical minimum value of BMI below which no risk was estimated was assumed to follow a uniform distribution from 20 kg/m2 to 25 kg/m2. Between 2000 and 2012, mean BMI increased by 6% from 27.7 kg/m2 (95% confidence interval (CI) 27.6 - 27.9) to 29.4 kg/m2 (95% CI 29.3 - 29.5) for females, and by 3% from 23.9 kg/m2 (95% CI 23.7 - 24.1) to 24.6 kg/m2 (95% CI 24.5 - 24.8) for males. In 2012, high BMI caused 58 757 deaths (95% uncertainty interval (UI) 46 740 - 67 590) or 11.1% (95% UI 8.8 - 12.8) of all deaths, and 1.42 million DALYs (95% UI 1.15 - 1.61) or 6.9% (95% UI 5.6 - 7.8) of all DALYs. Over the study period, the burden in females was ~1.5 - 1.8 times higher than that in males. Type 2 diabetes mellitus became the leading cause of death attributable to high BMI in 2012 (n=12 382 deaths), followed by hypertensive heart disease (n=12 146), haemorrhagic stroke (n=9 141), ischaemic heart disease (n=7 499) and ischaemic stroke (n=4 044). The age-standardised attributable DALY rate per 100 000 population for males increased by 6.6% from 3 777 (95% UI 2 639 - 4 869) in 2000 to 4 026 (95% UI 2 831 - 5 115) in 2012, while it increased by 7.8% for females from 6 042 (95% UI 5 064 - 6 702) to 6 513 (95% UI 5 597 - 7 033). Average BMI increased between 2000 and 2012 and accounted for a growing proportion of total deaths and DALYs. There is a need to develop, implement and evaluate comprehensive interventions to achieve lasting change in the determinants and impact of overweight and obesity, particularly among women.

Estimating the burden of disease attributable to a diet low in fruit and vegetables in South Africa for 2000, 2006 and 2012.

Low intake of fruit and vegetables is associated with an increased risk of various non-communicable diseases, including major causes of death and disability such as cardiovascular disease, diabetes mellitus and cancers. Diets low in fruit and vegetables are prevalent in the South African (SA) population, and average intake is well below the internationally recommended threshold. To estimate the burden of disease attributable to a diet low in fruit and vegetables by sex and age group in SA for the years 2000, 2006 and 2012. We followed World Health Organization and Global Burden of Disease Study comparative risk assessment methodology. Population attributable fractions - calculated from fruit and vegetable intake estimated from national and local surveys and relative risks for health outcomes based on the current literature - were applied to the burden estimates from the second South African National Burden of Disease Study (SANBD2). Outcome measures included deaths and disability-adjusted life years (DALYs) lost from ischaemic heart disease, stroke, type 2 diabetes, and five categories of cancers. Between 2000 and 2012, the average intake of fruit of the SA adult population (≥25 years) declined by 7%, from 48.5 g/d (95% uncertainty interval (UI) 46.6 - 50.5) to 45.2 g/d (95% UI 42.7 - 47.6). Vegetable intake declined by 25%, from 146.9 g/d (95% UI 142.3 - 151.8) to 110.5 g/d (95% UI 105.9 - 115.0). In 2012, these consumption patterns are estimated to have caused 26 423 deaths (95% UI 24 368 - 28 006), amounting to 5.0% (95% UI 4.6 - 5.3%) of all deaths in SA, and the loss of 514 823 (95% UI 473 508 - 544 803) healthy life years or 2.5% (95% UI 2.3 - 2.6%) of all DALYs. Cardiovascular disease comprised the largest proportion of the attributable burden, with 83% of deaths and 84% of DALYs. Age-standardised death rates were higher for males (145.1 deaths per 100 000; 95% UI 127.9 - 156.2) than for females (108.0 deaths per 100 000; 95% UI 96.2 - 118.1); in both sexes, rates were lower than those observed in 2000 (-9% and -12%, respectively). Despite the overall reduction in standardised death rates observed since 2000, the absolute burden of disease attributable to inadequate intake of fruit and vegetables in SA remains of significant concern. Effective interventions supported by legislation and policy are needed to reverse the declining trends in consumption observed in most age categories and to curb the associated burden.

Estimating the changing disease burden attributable to iron deficiency in South Africa, 2000, 2006 and 2012.

Worldwide, iron deficiency, and consequent iron-deficiency anaemia, remains the most common nutritional disorder. Iron-deficiency anaemia mostly affects young children and women of reproductive age, especially in Asia and Africa. Iron deficiency may contribute to disability directly or indirectly as a risk factor for other causes of death, and may rarely contribute to death. To estimate the changing burden of disease attributable to iron deficiency in males and females (all ages) for the years 2000, 2006 and 2012 in South Africa (SA). The comparative risk assessment methodology developed by the World Health Organization (WHO) and the Global Burden of Diseases, Injuries, and Risk Factors Studies was used to estimate the burden attributable to iron deficiency in SA for the years 2000, 2006 and 2012. We attributed 100% of the estimated iron-deficiency anaemia burden across all age groups by sex to iron deficiency. For maternal conditions, the attributable burden to iron deficiency was calculated using the counterfactual method and applied to all women of reproductive age. The population attributable fraction calculated for these selected health outcomes was then applied to local burden estimates from the Second SA National Burden of Disease Study (SANBD2). Age-standardised rates were calculated using WHO world standard population weights and SA mid-year population estimates. There was a slight decrease in the prevalence of iron-deficiency anaemia in women of reproductive age from ~11.9% in 2000 to 10.0% in 2012, although the prevalence of anaemia fluctuated over time (25.5% - 33.2%), with a peak in 2006. There has been a gradual decline in the number of deaths from maternal conditions attributable to iron deficiency in SA between 2000 (351 deaths (95% uncertainty interval (UI) 248 - 436)) and 2012 (307 deaths (95% UI 118 - 470)), with a peak in 2006 (452 deaths (95% UI 301 - 589)). Furthermore, our analysis showed a 26% decrease between 2000 and 2012 in the age-standardised burden rates from maternal conditions (truncated to 15 - 49 years) attributable to iron deficiency. Between 2000 and 2012, the age-standardised disability-adjusted life year (DALY) rate from iron-deficiency anaemia attributable to iron deficiency markedly decreased by 33% in males, and increased by 3% in females of all ages. Approximately 1.1 - 1.4% of all DALYs in SA from 2000 to 2012 were attributable to iron deficiency. Iron-deficiency anaemia prevalence can be markedly reduced if iron deficiency is eliminated. Hence it is essential to encourage, reappraise and strengthen the measures that have been put in place to address iron deficiency, especially in women of reproductive age and children.

Estimating the changing burden of disease attributable to alcohol use in South Africa for 2000, 2006 and 2012.

Alcohol use was one of the leading contributors to South Africa (SA)'s disease burden in 2000, accounting for 7% of deaths and disability-adjusted life years (DALYs) in the first South African Comparative Risk Assessment Study (SACRA1). Since then, patterns of alcohol use have changed, as has the epidemiological evidence pertaining to the role of alcohol as a risk factor for infectious diseases, most notably HIV/AIDS and tuberculosis (TB). To estimate the burden of disease attributable to alcohol use by sex and age group in SA in 2000, 2006 and 2012. The analysis follows the World Health Organization (WHO)'s comparative risk assessment methodology. Population attributable fractions (PAFs) were calculated from modelled exposure estimated from a systematic assessment and synthesis of 17 nationally representative surveys and relative risks based on the global review by the International Model of Alcohol Harms and Policies. PAFs were applied to the burden of disease estimates from the revised second South African National Burden of Disease Study (SANBD2) to calculate the alcohol-attributable burden for deaths and DALYs for 2000, 2006 and 2012. We quantified the uncertainty by observing the posterior distribution of the estimated prevalence of drinkers and mean use among adult drinkers (≥15 years old) in a Bayesian model. We assumed no uncertainty in the outcome measures. The alcohol-attributable disease burden decreased from 2000 to 2012 after peaking in 2006, owing to shifts in the disease burden, particularly infectious disease and injuries, and changes in drinking patterns. In 2012, alcohol-attributable harm accounted for an estimated 7.1% (95% uncertainty interval (UI) 6.6 - 7.6) of all deaths and 5.6% (95% UI 5.3 - 6.0) of all DALYs. Attributable deaths were split three ways fairly evenly across major disease categories: infectious diseases (36.4%), non-communicable diseases (32.4%) and injuries (31.2%). Top rankings for alcohol-attributable DALYs for specific causes were TB (22.6%), HIV/AIDS (16.0%), road traffic injuries (15.9%), interpersonal violence (12.8%), cardiovascular disease (11.1%), cancer and cirrhosis (both 4%). Alcohol remains an important contributor to the overall disease burden, ranking fifth in terms of deaths and DALYs. Although reducing overall alcohol use will decrease the burden of disease at a societal level, alcohol harm reduction strategies in SA should prioritise evidence-based interventions to change drinking patterns. Frequent heavy episodic (i.e. binge) drinking accounts for the unusually large share of injuries and infectious diseases in the alcohol-attributable burden of disease profile. Interventions should focus on the distal causes of heavy drinking by focusing on strategies recommended by the WHO's SAFER initiative.

Estimating the changing burden of disease attributable to high sodium intake in South Africa for 2000, 2006 and 2012.

Elevated sodium consumption is associated with increased blood pressure, a major risk factor for cardiovascular and chronic kidney disease. To quantify the deaths and disability-adjusted life years (DALYs) attributed to high sodium intake in persons aged ≥25 years in South Africa (SA) for 2000, 2006 and 2012. Comparative risk assessment (CRA) methodology was used and population attributable fractions (PAFs) of high sodium intake, mediated through high blood pressure (BP), for cardiovascular and chronic kidney disease were estimated. This was done by taking the difference between the PAF for elevated systolic BP (SBP) based on the estimated SBP level in the population and the PAF based on the estimated SBP that would result if sodium intake levels were reduced to the theoretical minimum risk exposure level (1 g/day) according to population group and hypertension categories. A meta-regression based on data from nine national surveys conducted between 1998 and 2017 was used to estimate the prevalence of hypertension by age, sex and population group. Relative risks identified from international literature were used and the difference in PAFs was applied to local burden estimates from the second South African National Burden of Disease Study. Age-standardised rates were calculated using World Health Organization (WHO) standard population weights. The attributable burden was also estimated for 2012 using an alternative target of 2 g/day proposed in the National Strategic Plan for the Prevention and Control of Non-communicable Diseases (NSP). High sodium intake as mediated through high SBP was estimated to cause 8 071 (95% uncertainty interval (UI) 6 542 - 15 474) deaths in 2012, a drop from 9 574 (95% UI 8 158 - 16 526) in 2006 and 8 431 (95% UI 6 972 - 14 511) in 2000. In 2012, ischaemic heart disease caused the highest number of deaths in persons (n=1 832), followed by haemorrhagic stroke (n=1 771), ischaemic stroke (n=1 484) and then hypertensive heart disease (n=1 230). Ischaemic heart disease was the highest contributor to deaths for males (27%), whereas for females it was haemorrhagic stroke (23%). In 2012, 1.5% (95% UI 1.3 - 2.9) of total deaths and 0.7% (95% UI 0.6 - 1.2) of total DALYs were attributed to high sodium intake. If the NSP target of <2 g/day sodium intake had been achieved in 2012, ~2 943 deaths and 48 870 DALYs would have been averted. Despite a slight decreasing trend since 2006, high sodium intake mediated through raised BP accounted for a sizeable burden of disease in 2012. Realising SA's target to reduce sodium intake remains a priority, and progress requires systematic monitoring and evaluation.