Global Burden Of Disease Project Research Articles

Mortality of HIV-Infected Patients Starting Antiretroviral Therapy in Sub-Saharan Africa: Comparison with HIV-Unrelated Mortality

Mortality in HIV-infected patients who have access to highly active antiretroviral therapy (ART) has declined in sub-Saharan Africa, but it is unclear how mortality compares to the non-HIV-infected population. We compared mortality rates observed in HIV-1-infected patients starting ART with non-HIV-related background mortality in four countries in sub-Saharan Africa. Patients enrolled in antiretroviral treatment programmes in Côte d'Ivoire, Malawi, South Africa, and Zimbabwe were included. We calculated excess mortality rates and standardised mortality ratios (SMRs) with 95% confidence intervals (CIs). Expected numbers of deaths were obtained using estimates of age-, sex-, and country-specific, HIV-unrelated, mortality rates from the Global Burden of Disease project. Among 13,249 eligible patients 1,177 deaths were recorded during 14,695 person-years of follow-up. The median age was 34 y, 8,831 (67%) patients were female, and 10,811 of 12,720 patients (85%) with information on clinical stage had advanced disease when starting ART. The excess mortality rate was 17.5 (95% CI 14.5-21.1) per 100 person-years SMR in patients who started ART with a CD4 cell count of less than 25 cells/microl and World Health Organization (WHO) stage III/IV, compared to 1.00 (0.55-1.81) per 100 person-years in patients who started with 200 cells/microl or above with WHO stage I/II. The corresponding SMRs were 47.1 (39.1-56.6) and 3.44 (1.91-6.17). Among patients who started ART with 200 cells/microl or above in WHO stage I/II and survived the first year of ART, the excess mortality rate was 0.27 (0.08-0.94) per 100 person-years and the SMR was 1.14 (0.47-2.77). Mortality of HIV-infected patients treated with combination ART in sub-Saharan Africa continues to be higher than in the general population, but for some patients excess mortality is moderate and reaches that of the general population in the second year of ART. Much of the excess mortality might be prevented by timely initiation of ART.

Uncovering Pneumococcal Disease Burden in Bangladesh

Uncovering Pneumococcal Disease Burden in Bangladesh

The end of life: unknown and unplanned?

In an age when we can map the human genome and communicate globally across the Internet, it is amazing how little we know about the experience of people towards the end of life. For those who die, we do not know how many feel pain at the end of life their lives, how many receive effective symptom control, how many die in the place they want to be cared for, or what the quality of their care is. We do not know how many families feel supported during or after the illness, or to what extent this strains them and their finances. We also do not know what it costs to care for people towards the end of their lives, although there are global concerns about the inappropriate use of expensive technologies at the end of life.1 These issues are only just beginning to be addressed in cancer and even here knowledge is still patchy. This lack of knowledge is especially acute now, because of the changes in the patterns of illness across the world. In most countries populations are ageing rapidly.2 Increasingly, more people die as a result of serious chronic disease. More people are now living with the effects of serious chronic illnesses towards the end of life. Older people in particular are more likely to suffer from multi-organ failure. The WHO Global Burden of Disease Project predicts that in 2020 the top five causes of death will be heart disease, cerebrovascular disease, chronic respiratory disease, respiratory infections and lung cancer.3 In …

Projections of Global Mortality and Burden of Disease from 2002 to 2030

BackgroundGlobal and regional projections of mortality and burden of disease by cause for the years 2000, 2010, and 2030 were published by Murray and Lopez in 1996 as part of the Global Burden of Disease project. These projections, which are based on 1990 data, continue to be widely quoted, although they are substantially outdated; in particular, they substantially underestimated the spread of HIV/AIDS. To address the widespread demand for information on likely future trends in global health, and thereby to support international health policy and priority setting, we have prepared new projections of mortality and burden of disease to 2030 starting from World Health Organization estimates of mortality and burden of disease for 2002. This paper describes the methods, assumptions, input data, and results.Methods and FindingsRelatively simple models were used to project future health trends under three scenarios—baseline, optimistic, and pessimistic—based largely on projections of economic and social development, and using the historically observed relationships of these with cause-specific mortality rates. Data inputs have been updated to take account of the greater availability of death registration data and the latest available projections for HIV/AIDS, income, human capital, tobacco smoking, body mass index, and other inputs. In all three scenarios there is a dramatic shift in the distribution of deaths from younger to older ages and from communicable, maternal, perinatal, and nutritional causes to noncommunicable disease causes. The risk of death for children younger than 5 y is projected to fall by nearly 50% in the baseline scenario between 2002 and 2030. The proportion of deaths due to noncommunicable disease is projected to rise from 59% in 2002 to 69% in 2030. Global HIV/AIDS deaths are projected to rise from 2.8 million in 2002 to 6.5 million in 2030 under the baseline scenario, which assumes coverage with antiretroviral drugs reaches 80% by 2012. Under the optimistic scenario, which also assumes increased prevention activity, HIV/AIDS deaths are projected to drop to 3.7 million in 2030. Total tobacco-attributable deaths are projected to rise from 5.4 million in 2005 to 6.4 million in 2015 and 8.3 million in 2030 under our baseline scenario. Tobacco is projected to kill 50% more people in 2015 than HIV/AIDS, and to be responsible for 10% of all deaths globally. The three leading causes of burden of disease in 2030 are projected to include HIV/AIDS, unipolar depressive disorders, and ischaemic heart disease in the baseline and pessimistic scenarios. Road traffic accidents are the fourth leading cause in the baseline scenario, and the third leading cause ahead of ischaemic heart disease in the optimistic scenario. Under the baseline scenario, HIV/AIDS becomes the leading cause of burden of disease in middle- and low-income countries by 2015.ConclusionsThese projections represent a set of three visions of the future for population health, based on certain explicit assumptions. Despite the wide uncertainty ranges around future projections, they enable us to appreciate better the implications for health and health policy of currently observed trends, and the likely impact of fairly certain future trends, such as the ageing of the population, the continued spread of HIV/AIDS in many regions, and the continuation of the epidemiological transition in developing countries. The results depend strongly on the assumption that future mortality trends in poor countries will have a relationship to economic and social development similar to those that have occurred in the higher-income countries.

Estimating the prevalence of schizophrenia in Spain using a disease model

There are two main sources of information on the epidemiology of schizophrenia: prevalence and incidence studies. Prevalence rates can be estimated from incidence figures, and vice versa. The present article aims to provide an estimate of the prevalence of schizophrenia in Spain, calculated from epidemiological and demographic data, using a disease model of schizophrenia which applies the specific methodology of the WHO Global Burden of Disease project. Our model assumes a causal relationship between incidence and prevalence, but takes into account other competing risk factors of mortality; this approach is more realistic than one assuming a simple linear relationship between both parameters. Our findings indicate an estimated mean prevalence of 3.0 per 1000 inhabitants per year for men, but slightly lower for women: 2.86 per 1000. Our model enables us to compare incidence figures with those provided by prevalence studies and obtain accurate estimates of the distribution of schizophrenia in the general population, which can be used to better identify treatment needs and the consequent allocation of resources.

The burden of cancer attributable to alcohol drinking

We estimated the number of cancer cases and deaths attributable to alcohol drinking in 2002 by sex and WHO subregion, based on relative risks of cancers of the oral cavity, pharynx, esophagus, liver, colon, rectum, larynx and female breast obtained from recent meta- and pooled analyses and data on prevalence of drinkers obtained from the WHO Global Burden of Disease project. A total of 389,100 cases of cancer are attributable to alcohol drinking worldwide, representing 3.6% of all cancers (5.2% in men, 1.7% in women). The corresponding figure for mortality is 232,900 deaths (3.5% of all cancer deaths). This proportion is particularly high among men in Central and Eastern Europe. Among women, breast cancer comprises 60% of alcohol-attributable cancers. Although our estimates are based on simplified assumptions, the burden of alcohol-associated cancer appears to be substantial and needs to be considered when making public health recommendations on alcohol drinking.

Global burden of disease (GBD) for hepatitis C.

Hepatitis C virus (HCV) infection is now a global public health issue. However, the global burden of disease attributable to HCV infection is unknown. The objectives of this WHO informal consultation included the following: (1) defining a strategy to estimate the global burden of disease (GBD) associated with HCV infection in terms of morbidity and mortality, (2) describing the natural history of HCV infection in terms of morbidity and mortality, and (3) identifying areas for which more research is needed. The GBD project is an attempt to examine all causes of morbidity and mortality using an approach common to all conditions. The World Health Organization (WHO) already has estimated the burden of disease associated with hepatitis B virus (HBV) infection and is now about to conduct the same analysis for HCV infection. A review has been conducted to estimate the prevalence of HCV infection by age, gender, and region. These figures can be used to estimate incidence, although there are a number of areas of uncertainty. Combined with natural history parameters, incidence estimates could be used to estimate the future burden due to current infections. However, the present model is not validated and requires calibration before it can be used. A consensus was reached over the strategies to be used to (1) estimate the current burden due to past infections and (2) estimate the future burden due to current infections. Provisional expert consensus was reached over natural history parameters and cofactors that influence them. However, systematic literature reviews and meta-analysis are preferable for obtaining estimates to be included in models. Areas deserving future research include (1) obtaining a better estimate of HCV infection prevalence by age groups, (2) characterizing the various morbidity states associated with HCV infection and their disability weights, (3) understanding the long-term natural history of HCV infection beyond 20 years after infection, and (4) estimating the prevalence (and numbers of) of HCV infection among the drug-using population worldwide. A working group was created to address unmet needs and to assist the WHO in estimating the GBD associated with HCV infection.

Use of injections in healthcare settings worldwide, 2000: literature review and regional estimates

Objective To describe injection practices worldwide in terms of frequency and safety.Design Literature review. The global burden of disease project of the World Health Organization defined 14 regions on the...

Comparação das informações sobre as prevalências de doenças crônicas obtidas pelo suplemento saúde da PNAD/98 e as estimadas pelo estudo Carga de Doença no Brasil

Neste estudo, estimativas de prevalência de cinco doenças crônicas cirrose, depressão, diabetes, insuficiência renal crônica e tuberculose obtidas pelo Suplemento Saúde da PNAD/98 foram comparadas com as obtidas no Projeto Carga Global de Doença no Brasil. Essas estimativas foram baseadas em análise sistemática de literatura e banco de dados de morbidade disponíveis. Os resultados mostram que a PNAD apresentou número de casos mais elevados para depressão e insuficiência renal crônica, enquanto as estimativas do Projeto Carga de Doença no Brasil apresentou maiores prevalências para cirrose, diabetes e tuberculose.

Targets in health policy

In the 1980s epidemiology was rediscovered by health policy makers and health target setting was introduced. Although it brought back the populations' health as the central goal in health policy, some problems were also identified with the use of targets. First, of course, the political risk of being so explicit in a field where one does not control all the relevant determinants. Secondly, problems were encountered in terms of epidemiological methodology and data availability. However, the fact that in some countries targets could be sustained over several cabinets shows that they may also help to keep health policy on a steady course. In addition, public health epidemiology and public health models have since provided many of the tools necessary to set realistic targets and to translate the results of epidemiological research adequately into estimates of the potential health benefits of alternative interventions. Not long ago the World Health Organisation (WHO) presented its new generation of targets, in its policy 'Health for All in the 21st Century'. With these targets the WHO has once again chosen to put social justice and the public's health high on the health policy agenda. It is to be hoped that the progress which has been made with the methodology of public health epidemiology and the necessary data for the member states in the next Global Burden of Disease project will allow for the use of these targets in the core of policy making, the priority setting of resource allocation.

Is it feasible or desirable to measure burdens of disease as a single number?

This paper questions the feasibility and desirability of creating a composite health index, such as the DALY (disability adjusted life years), that aggregates information about both mortality and morbidity into one number, to represent the burden of disease. Despite the expressed intention not to include contextual factors in the description of health states, in practice, doing so is unavoidable when trying to construct a health indicator. Including contextual factors leads to severe problems, however, regarding validity and reliability, and these are increased when evaluations of the described health states are made. This renders little confidence in DALYs as a measurement of the burden of disease. Using cost-effectiveness analyses and DALYs as tools in priority setting might have unwanted consequences, and this is not the only method of achieving economic efficiency. The use of this method might also serve to relieve politicians of the responsibility for resource allocation in the health sector. An alternative to a composite index is better and more comprehensive epidemiological data on sexual and reproductive health mortality, morbidity and diseases rather than the better use of health indicators of questionable validity and reliability. These kinds of data are nowbeing collected in connection with the Global Burden of Disease Project. It should be up to the decisions-makers to allocate existing resources based on a balancing of the many good purposes and goals available.

Global Burden of Disease and Injury Due to Occupational Factors

We made estimates of absolute morbidity and mortality due to occupational factors for the world using all available published data as of 1994, and, where no data were available, applying the most appropriate (in terms of similar economy, race, and environment) age-/sex-/diagnosis-specific incidence and mortality rates to known working population distributions. We report results according to economic groupings determined by the World Bank (World Development Report, 1993) and disease and injury groupings according to The Global Burden of Disease project (1997). This was part of a larger study that estimated the total global disease burden. We present aggregate results and analyses by region and disease. We estimate that approximately 100,000,000 occupational injuries (100,000 deaths) and 11,000,000 occupational diseases (700,000 deaths) occur in the world each year. We regard these as very conservative estimates which, although unavoidably crude, can nevertheless provide a basis for health priority planning at global level.

Blood Pressure and the Global Burden of Cardiovascular Disease

Cardiovascular disease is responsible for a large and increasing proportion of death and disability worldwide. Half of this burden occurs in Asia. This study assessed the possible effects of population-wide (2% lower DBP for all) and targeted (7% lower DBP for those with usual DBP ≥ 95 mmHg) BP interventions in Asia, using data from surveys of blood pressure levels, the Global Burden of Disease Project, Eastern Asian cohort studies and randomised trials of blood pressure lowering. Overall each of the two interventions would be expected to avert about one million deaths per year throughout Asia in 2020. These benefits would be approximately additive. About half a million deaths might be averted annually by each intervention in China alone, with about four-fifths of this benefit due to averted stroke. The relative benefits of these two strategies are similar to estimates made for US and UK populations. However, the absolute benefits are many times greater due to the size of the predicted CVD burden in Asia.