The Global Burden of Disease Assessments—WHO Is Responsible?

et al. (2007) The Global Burden of Disease Assessments-WHO Is Responsible? PLoS Negl Trop Dis 1(3): e161. doi:10.1371/journal.pntd.0000161 The Global Burden of Disease Assessments-WHO Is Responsible? Claudia Stein 0 Tanja Kuchenmu ller 0 Saskia Hendrickx 0 Annette Pru ss-U stu n 0 Lara Wolfson 0 Dirk Engels 0 Jrgen Schlundt 0 Juerg Utzinger, Swiss Tropical Institute, Switzerland 0 World Health Organization , Geneva , Switzerland The Global Burden of Disease (GBD) concept has been used by the World Health Organization (WHO) for its reporting on health information for nearly 10 years. The GBD approach results in a single summary measure of morbidity, disability, and mortality, the so-called disabilityadjusted life year (DALY). To ensure transparency and objectivity in the derivation of health information, WHO has been urged to use reference groups of external experts to estimate burden of disease. Under the leadership and coordination of WHO, expert groups have been appraising and abstracting burden of disease information. Examples include the Child Health Epidemiology Reference Group (CHERG), the Malaria Monitoring and Evaluation Reference Group (MERG), and the recently established Foodborne Disease Burden Epidemiology Reference Group (FERG). The structure and functioning of and lessons learnt by these groups are described in this paper. External WHO expert groups have provided independent scientific health information while operating under considerable differences in structure and functioning. Although it is not appropriate to devise a single ''best practice'' model, the common thread described by all groups is the necessity of WHO's leadership and coordination to ensure the provision and dissemination of health information that is to be globally accepted and valued. - Borrowing the words of the New Testament Apostle Paul, Samuel H. Preston stated that before 1990, the global disease landscape...was perceived through a glass darkly [1]. Indeed, the Global Burden of Disease (GBD) 1990 series [2] was a landmark publication that constructed an internally consistent global overview of morbidity, disability, and mortality burden for some 130 diseases and conditions. Frustrated by fragmented, incomplete, incomparable, and often advocacy-driven health information, the authors of the GBD 1990 synthesized a plethora of data and health measures into a single health metric, the so-called disability-adjusted life year (DALY), thus permitting policy makers to directly compare the burden of different diseases, set priorities, and evaluate the cost-effectiveness of their interventions. The World Health Organization (WHO) was a major partner in the GBD 1990 study and officially adopted its approach for reporting on health information in the late 1990s. Soon individual technical units and programs within WHO used and further developed the method and built collaborations with external experts to publish disease burden estimates beyond the classic GBD cause list [35]. Since then, the tapestry of burden of disease assessments has continued to grow, and major collaborative initiatives have emerged to this effect at WHO in recent years. In this paper, we describe WHOs responsibility in global burden of disease assessment and summarize major ongoing and planned activities in the synthesis and appraisal of existing and new global burden of disease data put forward by WHO. We explore the critical role of WHO in these efforts and outline how areas of collaboration, partnership, and synergy can be forged to provide credible and meaningful global health statistics. However, the function and activities of the WHO department specifically dedicated to health information, including the hosting of the global partnership of the Health Metrics Network [6], are sufficiently extensive to be dealt with in a separate publication in this series [7]. The GBD approach was developed in the 1980s with the commissioning of cost-effectiveness analyses by the World Bank. The results of this effort were first published in the World Development Report 1993 [8] and the Disease Control Priorities in Developing Countries project [9]. Since adopting the GBD approach in its health reporting, WHO has not only undertaken a major review of the GBD 1990 with its GBD 2000 publications [10], but also provided annual updates in the annex tables of the World Health Report [11]. Moreover, in collaboration with external scientists, WHO developed creative new methodologies for the assessment of disease burden resulting from risk factors [12]. The latter included a widely publicized contribution estimating the GBD from environmental factors such as unsafe water and sanitation, climate change, unsafe sex, and lead exposure, among others. The DALY approach brought new knowledge to the public health community, which was particularly evident in the World Health Report 2001Mental Health: New Understanding, New Hope [13]. This publication quantified for the first time the silent burden of mental disorders by identifying depressive disorders as the leading cause of disability among men and women world-wide. A succinct summary of the GBD study and its evolution is given by Mathers et al. [7]. The technical approach of the GBD is complex, both in concept and in application, and the interpretation of results requires detailed methodological knowledge. As WHO increasingly used these approaches, it was urged by Member States and international scientists to provide more transparency in the underlying methods and inputs used [14]. This was a particular concern in the wake of the World Health Report 2000, which controversially published a league-table of countries health systems performance using complex mathematical models [15]. In 2005, WHO therefore convened an international high-level advisory panel on health statistics [16], which recommended that WHO work with external reference groups to ensure accuracy and transparency of estimates. The panel made a number of detailed recommendations in the areas of data collection and reporting, comparability of statistics between countries, and the provision of time series of epidemiological information, as well as the reporting of uncertainty ranges, especially when providing country-level estimates. Moreover, the panel advised WHO to make major efforts to support the in-country application of estimation procedures, including the simplification of tools and methods and building of national capacity. The high-level panel echoed statements previously made by Burden of Disease champions, including Christopher Murray, who expressed hope that WHO would advance the GBD methods [17]. The panel particularly emphasized WHOs constitutional and legitimate link with its Member States [16], which mandates the reporting of health data, capitalizes on the convening power of WHO to reach consensus and its leadership to develop and harmonize methods and tools for health information, in collaboration with releva (...truncated)