LS iY D UB I7 Statistical annex The six tables in this technical annex present updated information on summary measures of population health, mortality and the burden of disease in WHO Member States and regions, and selected national health accounts aggregates for 1997-2001. Life expectancy and healthy life expectancy estimates and the national health accounts aggregates have been revised to take new data into account and, for many Member States, are not directly comparable with those published in The World Health Report 2002. The work leading to these annex tables was undertaken mostly by the WHO Global Programme on Evidence for Health Policy in colla boration with counterparts from WHO regional offices and representatives of WHO in Member States Where data are presented by country, initial WHO estimates and technical explanations were sent to Member States for comment. The estimates reported here should, however, still be interpreted as being the best estimates of Who rather than the official viewpoints of Member States
Statistical Annex 133 Statistical Annex The six tables in this technical annex present updated information on summary measures of population health, mortality and the burden of disease in WHO Member States and regions, and selected national health accounts aggregates for 1997–2001. Life expectancy and healthy life expectancy estimates and the national health accounts aggregates have been revised to take new data into account and, for many Member States, are not directly comparable with those published in The World Health Report 2002. The work leading to these annex tables was undertaken mostly by the WHO Global Programme on Evidence for Health Policy in collaboration with counterparts from WHO regional offices and representatives of WHO in Member States. Where data are presented by country, initial WHO estimates and technical explanations were sent to Member States for comment. The estimates reported here should, however, still be interpreted as being the best estimates of WHO rather than the official viewpoints of Member States
134 The World Health Report 2003
Statistical annex Explanatory notes The tables in this technical annex present updated information on summary measures of population health, mortality and the burden of disease in WHO Member States and regions, and selected national health accounts aggregates for 1997-2001. Life expectancy and healthy life expectancy estimates and the national health accounts aggregates have been revised to take new data into account and, for many Member States, are not directly comparable with those published in The World Health Report 2002. The work leading to these annex tables wa undertaken mostly by the WHo Global Programme on Evidence for Health Policy in col laboration with counterparts from WHO regional offices and representatives of WHO in Member States. These notes provide an overview of concepts, methods and data sources gether with references to more detailed documentation It is hoped that careful scrutiny and use of the results will lead to progressive improvements in the measurement of health attainment and health system financing in future editions of The World Health Report. The main results in the health attainment tables are reported with ncertainty intervals in order to communicate to the user the plausible range of estimates for each country on each measure Where data are presented by country, initial WHO estimates and technical explanations were sent to Member States for comment. Comments or data provided in response were discussed with the Member State and incorporated where possi- ble. The estimates reported here should, however, still be interpreted as being the best esti ates of Who rather than the official viewpoints of Member States Annex Table 1 To assess overall levels of health achievement, it is crucial to develop the best possible ment of the life table for each country. New life tables have been developed for all 192 Mem ber States starting with a systematic review of all available evidence from surveys, censuses sample registration systems, population laboratories and vital registration on levels and trends in child mortality and adult mortality (1). This review benefited greatly from a collaborative assessment of child mortality levels for 2001 by WHO and UNICEF and from analyses of general mortality by the United States Census Bureau(2)and the United Nations Populatic All estimates of population size and structure for 2002 are based on the 2002 demographic assessments prepared by the United Nations Population Division(3). These estimates refer to the de facto population and not the de jure population in each Member State. To aid in
Statistical Annex 135 The tables in this technical annex present updated information on summary measures of population health, mortality and the burden of disease in WHO Member States and regions, and selected national health accounts aggregates for 1997–2001. Life expectancy and healthy life expectancy estimates and the national health accounts aggregates have been revised to take new data into account and, for many Member States, are not directly comparable with those published in The World Health Report 2002. The work leading to these annex tables was undertaken mostly by the WHO Global Programme on Evidence for Health Policy in collaboration with counterparts from WHO regional offices and representatives of WHO in Member States. These notes provide an overview of concepts, methods and data sources together with references to more detailed documentation. It is hoped that careful scrutiny and use of the results will lead to progressive improvements in the measurement of health attainment and health system financing in future editions of The World Health Report. The main results in the health attainment tables are reported with uncertainty intervals in order to communicate to the user the plausible range of estimates for each country on each measure. Where data are presented by country, initial WHO estimates and technical explanations were sent to Member States for comment. Comments or data provided in response were discussed with the Member State and incorporated where possible. The estimates reported here should, however, still be interpreted as being the best estimates of WHO rather than the official viewpoints of Member States Annex Table 1 To assess overall levels of health achievement, it is crucial to develop the best possible assessment of the life table for each country. New life tables have been developed for all 192 Member States starting with a systematic review of all available evidence from surveys, censuses, sample registration systems, population laboratories and vital registration on levels and trends in child mortality and adult mortality (1). This review benefited greatly from a collaborative assessment of child mortality levels for 2001 by WHO and UNICEF and from analyses of general mortality by the United States Census Bureau (2) and the United Nations Population Division (3). All estimates of population size and structure for 2002 are based on the 2002 demographic assessments prepared by the United Nations Population Division (3). These estimates refer to the de facto population and not the de jure population in each Member State. To aid in Statistical Annex Explanatory notes
The World Health Report 2003 demographic, cause-of-death and burden-of-disease analyses, the 192 Member States have been divided into five mortality strata on the basis of their level of child and adult male mortality. The matrix defined by the six WHO regions and the five mortality strata leads to 14 subregions, since not every mortality stratum is represented in every region. These subregions are defined on pages 184-185 and used in Tables 2 and 3 for presentation of Because of increasing heterogeneity of patterns of adult and child mortality, WHO has devel oped a model life table system of two-parameter logit life tables using a global standard, and with additional age-specific parameters to correct for systematic biases in the application of a two-parameter system(4). This system of model life tables has been used extensively in the development of life tables for those Member States without adequate vital registration and in projecting life tables to 2002 when the most recent data available are from earlier year Demographic techniques(Preston-Coale method, Brass Growth-Balance method, General- ized Growth-Balance method and Bennett-Horiuchi method)have been applied, as appro- priate, to assess the level of completeness of recorded mortality data for Member States with vital registration systems. For Member States without national vital registration systems, all available survey, census and vital registration data were assessed, adjusted and averaged to estimate the probable trend in child mortality over the past few decades. This trend was projected to estimate child mortality levels in 2002. In addition, adult sibling survival data from available population surveys were analysed to obtain additional information on adult ortalit WHO uses a standard method to estimate and project life tables for all Member States with comparable data. This may lead to minor differences compared with official life tables pre pared by Member States. Life expectancies for the year 2002 for many Member States have been revised from those published for 2000 and 2001 in The World Health Report 2002 to take into account more recently available mortality data To capture the uncertainty resulting from sampling, indirect estimation technique or projec tion to 2002, a total of 1000 life tables have been developed for each Member State. Uncer- tainty bounds are reported in Annex Table l by giving key life table values at the 2. 5th percentile and the 97. 5th percentile. This uncertainty analysis was facilitated by the development of new methods and software tools(5). In countries with a substantial HIV/AIDS epidemic, recent estimates of the level and uncertainty range of the magnitude of the epidemic have been incorporated into the life table uncertainty analysis. Annex Tables 2 and 3 Causes of death in the 14 subregions and the world have been estimated based on data from 112 national vital registration systems that capture about 18.6 million deaths annually, repre senting one-third of all deaths occurring in the world. In addition, information from sample registration systems, population laboratories and epidemiological analyses of specific condi tions has been used to improve estimates of the cause-of-death patterns(6-16). These data are used to estimate death rates by age and sex for underlying causes of death as defined by the International Statistical Classification of Diseases and Related Health Problems(IcD classification rules Cause-of-death data have been carefully analysed to take into account incomplete coverage of vital registration in countries and the likely differences in cause-of-death patterns that would be expected in uncovered and often poorer sub-populations. Techniques to
136 The World Health Report 2003 demographic, cause-of-death and burden-of-disease analyses, the 192 Member States have been divided into five mortality strata on the basis of their level of child and adult male mortality. The matrix defined by the six WHO regions and the five mortality strata leads to 14 subregions, since not every mortality stratum is represented in every region. These subregions are defined on pages 184–185 and used in Tables 2 and 3 for presentation of results. Because of increasing heterogeneity of patterns of adult and child mortality, WHO has developed a model life table system of two-parameter logit life tables using a global standard, and with additional age-specific parameters to correct for systematic biases in the application of a two-parameter system (4). This system of model life tables has been used extensively in the development of life tables for those Member States without adequate vital registration and in projecting life tables to 2002 when the most recent data available are from earlier years. Demographic techniques (Preston–Coale method, Brass Growth–Balance method, Generalized Growth–Balance method and Bennett–Horiuchi method) have been applied, as appropriate, to assess the level of completeness of recorded mortality data for Member States with vital registration systems. For Member States without national vital registration systems, all available survey, census and vital registration data were assessed, adjusted and averaged to estimate the probable trend in child mortality over the past few decades. This trend was projected to estimate child mortality levels in 2002. In addition, adult sibling survival data from available population surveys were analysed to obtain additional information on adult mortality. WHO uses a standard method to estimate and project life tables for all Member States with comparable data. This may lead to minor differences compared with official life tables prepared by Member States. Life expectancies for the year 2002 for many Member States have been revised from those published for 2000 and 2001 in The World Health Report 2002 to take into account more recently available mortality data. To capture the uncertainty resulting from sampling, indirect estimation technique or projection to 2002, a total of 1000 life tables have been developed for each Member State. Uncertainty bounds are reported in Annex Table 1 by giving key life table values at the 2.5th percentile and the 97.5th percentile. This uncertainty analysis was facilitated by the development of new methods and software tools (5). In countries with a substantial HIV/AIDS epidemic, recent estimates of the level and uncertainty range of the magnitude of the epidemic have been incorporated into the life table uncertainty analysis. Annex Tables 2 and 3 Causes of death in the 14 subregions and the world have been estimated based on data from 112 national vital registration systems that capture about 18.6 million deaths annually, representing one-third of all deaths occurring in the world. In addition, information from sample registration systems, population laboratories and epidemiological analyses of specific conditions has been used to improve estimates of the cause-of-death patterns (6–16). These data are used to estimate death rates by age and sex for underlying causes of death as defined by the International Statistical Classification of Diseases and Related Health Problems (ICD) classification rules. Cause-of-death data have been carefully analysed to take into account incomplete coverage of vital registration in countries and the likely differences in cause-of-death patterns that would be expected in uncovered and often poorer sub-populations. Techniques to
Statistical annex undertake this analysis have been developed based on the global burden of disease study (17) and further refined using a much more extensive database and more robust modelling tech Special attention has been paid to problems of misattribution or miscoding of causes of death in cardiovascular diseases, cancer, injuries and in general ill-defined categories. A correction algorithm for reclassifying ill-defined cardiovascular codes has been developed (19).Cancer mortality by site has been evaluated using both vital registration data and population-based cancer incidence registries. The latter have been analysed using a complete age, period cohort Annex Table 3 provides estimates of the burden of disease for the 14 epidemiological subregions using disability-adjusted life years(DALYs). One DALY can be thought of as one lost year of healthy life and the burden of disease as a measurement of the gap between the current health of a population and an ideal situation in which everyone in the population lives into old age in full health(20, 21). DALYs for a disease or health condition are calculated as th sum of the years of life lost(YLL) through premature mortality in the population and the years lost through disability(YLD) for incident cases of the health condition. DALYs for 2002 have been estimated using cause-of-death information for each subregion and regional or country-level assessments of the epidemiology of major disabling conditions. For this report, burden-of-disease estimates have been updated for many of the cause categories included in the Global Burden of Disease 2000 study, based on the wealth of data on major diseases and njuries available to WHO technical programmes and through collaboration with scientists worldwide(16). These data, together with new and revised estimates of deaths by cause, and sex, for all Member States, have been used to develop internally consistent estimates of incidence, prevalence, duration and DALYs for over 130 major causes, for 14 subregions of the world WHO programme participation in the development of these estimates and con sultation with Member States ensures that estimates reflect all information and knowledge available to WHO. Estimates of incidence and point prevalence for selected major causes by subregionarealsoavailableontheWhowebsiteatwww.who.int/evidence/bod. Annex Table 4 Annex Table 4 reports the average level of population health for WHO Member States in terms of health-adjusted life expectancy(HALE). HALE is based on life expectancy at birth (Annex Table 1)but includes an adjustment for time spent in poor health. It is most easil understood as the equivalent number of years in full health that a newborn can expect to live based on current rates of ill-health and mortality(22, 23). The methods used by WHo to calculate hale have been developed to maximize compara bility across populations. WHO analyses of more than 50 existing national health surveys fo the calculation of healthy life expectancy identified severe limitations in the comparability of self-reported health status data from different populations, even when identical survey struments and methods were used(24). These comparability problems are a result of unmeasured differences in expectations and norms for health, so that the meaning different populations attach to the labels used for response categories in self-reported questions (such as mild, moderate or severe)can vary greatly (25). To resolve these problems, WHO under- took a Multi-Country Survey Study(MCSS )in 2000-2001 in collaboration with Member States, using a standardized health status survey instrument together with new statistical nethods for adjusting biases in self-reported health(25, 26)
Statistical Annex 137 undertake this analysis have been developed based on the global burden of disease study (17) and further refined using a much more extensive database and more robust modelling techniques (18). Special attention has been paid to problems of misattribution or miscoding of causes of death in cardiovascular diseases, cancer, injuries and in general ill-defined categories. A correction algorithm for reclassifying ill-defined cardiovascular codes has been developed (19). Cancer mortality by site has been evaluated using both vital registration data and population-based cancer incidence registries. The latter have been analysed using a complete age, period cohort model of cancer survival in each region (15). Annex Table 3 provides estimates of the burden of disease for the 14 epidemiological subregions using disability-adjusted life years (DALYs). One DALY can be thought of as one lost year of “healthy” life and the burden of disease as a measurement of the gap between the current health of a population and an ideal situation in which everyone in the population lives into old age in full health (20, 21). DALYs for a disease or health condition are calculated as the sum of the years of life lost (YLL) through premature mortality in the population and the years lost through disability (YLD) for incident cases of the health condition. DALYs for 2002 have been estimated using cause-of-death information for each subregion and regional or country-level assessments of the epidemiology of major disabling conditions. For this report, burden-of-disease estimates have been updated for many of the cause categories included in the Global Burden of Disease 2000 study, based on the wealth of data on major diseases and injuries available to WHO technical programmes and through collaboration with scientists worldwide (16). These data, together with new and revised estimates of deaths by cause, age and sex, for all Member States, have been used to develop internally consistent estimates of incidence, prevalence, duration and DALYs for over 130 major causes, for 14 subregions of the world. WHO programme participation in the development of these estimates and consultation with Member States ensures that estimates reflect all information and knowledge available to WHO. Estimates of incidence and point prevalence for selected major causes by subregion are also available on the WHO web site at www.who.int/evidence/bod. Annex Table 4 Annex Table 4 reports the average level of population health for WHO Member States in terms of health-adjusted life expectancy (HALE). HALE is based on life expectancy at birth (Annex Table 1) but includes an adjustment for time spent in poor health. It is most easily understood as the equivalent number of years in full health that a newborn can expect to live based on current rates of ill-health and mortality (22, 23). The methods used by WHO to calculate HALE have been developed to maximize comparability across populations. WHO analyses of more than 50 existing national health surveys for the calculation of healthy life expectancy identified severe limitations in the comparability of self-reported health status data from different populations, even when identical survey instruments and methods were used (24). These comparability problems are a result of unmeasured differences in expectations and norms for health, so that the meaning different populations attach to the labels used for response categories in self-reported questions (such as mild, moderate or severe) can vary greatly (25). To resolve these problems, WHO undertook a Multi-Country Survey Study (MCSS) in 2000–2001 in collaboration with Member States, using a standardized health status survey instrument together with new statistical methods for adjusting biases in self-reported health (25, 26)