Showing papers by "Christopher J L Murray published in 2004"

Comparative quantification of health risks : global and regional burden of disease attributable to selected major risk factors

Abstract: During the last quarter of the twentieth century, a number of works have addressed both the methodological and empirical aspects of population-wide impacts of major causes of diseases. This gradual establishment of "risk assessment" or "risk quantification" has been driven partly by the academic curiosity of individual researchers and partly by the demands of regulatory agencies and public policy for better quantitative evidence on the health implications of certain risk exposures. These efforts nonetheless have generally been within the disciplinary and methodological traditions of individual risk factors and in a limited number of settings. As a result, the criteria for evaluating scientific evidence have varied greatly across risk factors resulting in lack of comparability across risk factors. This book provides a comprehensive assessment of the scientific evidence on prevalence and hazards, and the resulting health effects, of a range of exposures that are known to be hazardous to human health, including childhood and maternal undernutrition, nutritional and physiological risk factors for adult health, addictive substances, sexual and reproductive health, and risks in the physical environments of households and communities, as well as among workers. This book is the culmination of over 3 years of scientific enquiry and data collection, collectively known as the comparative risk assessment (CRA) project, involving over 100 scientists, applying a common analytical framework and methods to ensure greater consistency and comparability in using and evaluating scientific evidence across risks. As a result, our understanding of the comparative extent of disease burden caused by various exposures worldwide has advanced, and key areas of scientific enquiry to better inform policy needs to reduce risks have been elucidated. As public health researchers and practitioners evaluate policy alternatives for improving population health, this book not only demonstrates the enormous potential for disease prevention, but also provides a fundamental reference for the scientific evidence on some of the most important global risks to health.

Global burden of depressive disorders in the year 2000

Abstract: Background The initial Global Burden of Disease study found that depression was the fourth leading cause of disease burden, accounting for 3.7% of total disability adjusted life years (DALYs) in the world in 1990. Aims To presentthe new estimates of depression burden for the year 2000. Method DALYs for depressive disorders in each world region were calculated, based on new estimates of mortality, prevalence, incidence, average age at onset, duration and disability severity. Results Depression is the fourth leading cause of disease burden, accounting for 4.4% of total DALYs in the year 2000, and it causes the largest amount of non-fatal burden, accounting for almost 12% of all total years lived with disability worldwide. Conclusions These data on the burden of depression worldwide represent a major public health problem that affects patients and society.

Comparability of self rated health: cross sectional multi-country survey using anchoring vignettes

Abstract: Objective To examine differences in expectations for health using anchoring vignettes, which describe fixed levels of health on dimensions such as mobility. Design Cross sectional survey of adults living in the community. Setting China, Myanmar, Sri Lanka, Pakistan, Turkey, and United Arab Emirates. Participants 3012 men and women aged 18 years and older (self ratings); subsample of 406 (vignette ratings). Main outcome measures Self rated mobility levels and ratings of hypothetical vignettes using the same questions and response categories. Results Consistent rankings of vignettes are evidence that vignettes are understood in similar ways in different settings, and internal consistency of orderings on two mobility questions indicates good comprehension. Variation in vignette ratings across age groups suggests that expectations for mobility decline with age. Comparison of responses to two different mobility questions supports the assumption that individual ratings of hypothetical vignettes relate to expectations for health in similar ways as self assessments. Conclusions Anchoring vignettes could provide a powerful tool for understanding and adjusting for the influence of different health expectations on self ratings of health. Incorporating anchoring vignettes in surveys can improve the comparability of self reported measures.

Distribution of major health risks: Findings from the global burden of disease study

Abstract: Background Most analyses of risks to health focus on the total burden of their aggregate effects. The distribution of risk-factor-attributable disease burden, for example by age or exposure level, can inform the selection and targeting of specific interventions and programs, and increase costeffectiveness.

Potential health gains from reducing multiple risk factors

Abstract: Portions of this chapter have been published previously in The Lancet, 2003, 362:271–280, and have been reproduced with permission from Elsevier Science.

Monitoring global health: time for new solutions

Abstract: Improved global health monitoring requires new technologies and methods, strengthened national capacity, norms and standards, and gold standard global reporting. The World Health Organization's many functions limit its capacity for global reporting, and a new global health monitoring organisation is needed to provide independent gold standard health information to the world.

The Global epidemiology of infectious diseases

Abstract: The collection and use of timely and reliable health information in support of health policies and programmes have been actively promoted by the World Health Organization since its foundation. Valid health statistics are required at all levels of the health system, ranging from data for health services support at the local community level, through to national statistics and information used to monitor the effectiveness of national health strategies. Equally, regional and global data are required to monitor global epidemics and to continuously assess the effectiveness of global public health approaches to disease and injury prevention and control, as coordinated by WHO technical programmes. Despite the clear need for epidemiological data, reliable and comprehensive health statistics are not available in many Member states of WHO, and, indeed, in many countries the ascertainment of disease levels, patterns and trends is still very uncertain.

Global patterns of healthy life expectancy in the year 2002.

Abstract: Background Healthy life expectancy – sometimes called health-adjusted life expectancy (HALE) – is a form of health expectancy indicator that extends measures of life expectancy to account for the distribution of health states in the population. The World Health Organization reports on healthy life expectancy for 192 WHO Member States. This paper describes variation in average levels of population health across these countries and by sex for the year 2002.

A multi-method approach to measuring health-state valuations.

Abstract: Existing techniques for eliciting health-state valuations incorporate both strength of preferences for health states and other values such as risk aversion or time preference. This paper presents a new methodological approach that allows estimation of a set of core underlying health-state values based on responses elicited through multiple measurement techniques. A study was undertaken in which respondents completed the visual analogue (VAS) scale, time trade-off (TTO), standard gamble (SG) and person trade-off (PTO) for a range of states. By specifying flexible parametric functions to explain responses on each measurement technique, we estimated both the underlying strength of preference values for the health states in the study and the values for a set of auxiliary parameters characterising risk attitudes, discount rates, distributional concerns and scale distortion effects in the group of respondents. This study demonstrates that it is possible to understand responses on these four different measurement techniques based on a consistent set of core values. The approach presented here can provide insights into different sources of observed variation in VAS, TTO, SG and PTO responses and facilitate appropriate adjustment of valuations elicited through different methods for use in summary health measures and economic analyses.

World health system performance revisited: the impact of varying the relative importance of health system goals.

Abstract: In 2002, the World Health Organization published a health system performance ranking for 191 member countries. The ranking was based on five indicators, with fixed weights common to all countries. We investigate the feasibility and desirability of using mathematical programming techniques that allow weights to vary across countries to reflect their varying circumstances and objectives. By global distributional measures, scores and ranks are found to be not very sensitive to changes in weights, although differences can be large for individual countries. Building the flexibility of variable weights into calculation of the performance index is a useful way to respond to the debates and criticisms appearing since publication of the ranking.

Mortality and burden of disease attributable to individual risk factors

Abstract: disease attributable to individual risk factors were calculated, as described in chapter 25, using risk factor exposure and hazard estimates provided in risk factor chapters. Mortality and burden of disease attributable to individual risk factors were then calculated by multiplying the PAFs by the estimates of total mortality and burden of disease from the Global Burden of Disease (GBD) databases in each of the 224 subregionage-sex groups, as described in chapter 25. These results are presented in the Annex Tables for each risk factor and summarized here across risks.

Estimating attributable burden of disease from exposure and hazard data

Abstract: RR(x): relative risk at exposure level x P(x): population distribution of exposure P¢(x): counterfactual distribution of exposure, and m: maximum exposure level The first and second terms in the numerator of Equation 1a represent the total exposure-weighted risk of disease or mortality in the population under current and counterfactual exposure distributions. The corresponding relationship when exposure is described as a discrete variable with n levels is given by: PIF RR x P x dx RR x P x dx

Conclusions and directions for future research

Abstract: using comparable methods as outlined in these volumes has ensured greater consistency and comparability in evaluating and using scientific evidence on major risks to health. At the same time, data and knowledge gaps identified in the analyses of these risks illustrate key areas of scientific enquiry necessary to better inform policies and programs that aim to prevent disease by reducing risk factor exposure. The principal findings were discussed in individual risk factor chapters, as well as in those that presented summary results for individual risk factors (chapter 26) and for the joint effects of multiple risks (chapter 27). In this chapter, we use these findings to describe broadly how the analyses might affect pubic health practice as well as research on risk factors. The analyses of the selected risk factors considered in this work, based on comprehensive reviews of available evidence on exposure and hazards, suggest that a small number of risks, such as childhood and maternal underweight and unsafe sex, accounted for a very large contribution to global loss of healthy life. Further, several risks, such as high blood pressure, tobacco and alcohol, have relative prominence in regions at all stages of development. While reducing all of the above risks to their theoretical minima may not be possible using current interventions, the results illustrate that disease prevention by addressing known distal and proximal risk factors can provide substantial, and under-appreciated, public health gains. Treatment of established disease will always have a role in public health, especially in the case of diseases such as tuberculosis where treatment contributes to prevention. At the same time, the current devotion of a disproportionately small share of resources to prevention by reducing exposure to major known risk factors, through personal and nonpersonal interventions, should be reconsidered in a more systematic way in the light of this evidence. Chapter 29