Neonatal cause-of-death estimates for the early and late neonatal periods for 194 countries: 2000–2013

ObjectiveTo estimate cause-of-death distributions in the early (0–6 days of age) and late (7–27 days of age) neonatal periods, for 194 countries between 2000 and 2013.MethodsFor 65 countries with high-quality vital registration, we used each country’s observed early and late neonatal proportional cause distributions. For the remaining 129 countries, we used multinomial logistic models to estimate these distributions. For countries with low child mortality we used vital registration data as inputs and for countries with high child mortality we used neonatal cause-of-death distribution data from studies in similar settings. We applied cause-specific proportions to neonatal death estimates from the United Nations Inter-agency Group for Child Mortality Estimation, by country and year, to estimate cause-specific risks and numbers of deaths.FindingsOver time, neonatal deaths decreased for most causes. Of the 2.8 million neonatal deaths in 2013, 0.99 million deaths (uncertainty range: 0.70–1.31) were estimated to be caused by preterm birth complications, 0.64 million (uncertainty range: 0.46–0.84) by intrapartum complications and 0.43 million (uncertainty range: 0.22–0.66) by sepsis and other severe infections. Preterm birth (40.8%) and intrapartum complications (27.0%) accounted for most early neonatal deaths while infections caused nearly half of late neonatal deaths. Preterm birth complications were the leading cause of death in all regions of the world.ConclusionThe neonatal cause-of-death distribution differs between the early and late periods and varies with neonatal mortality rate level. To reduce neonatal deaths, effective interventions to address these causes must be incorporated into policy decisions.     

Persistent and acute diarrhoea as the leading causes of child mortality in urban Guinea Bissau.

An investigation of child mortality in a semi-urban community, Bandim II, in the capital of Guinea Bissau was carried out from April 1987 to March 1990. 153 deaths were recorded among 1426 live-born children who were followed for 2753 child-years. The under-five mortality risk was 215 per 1000 children (95% confidence interval [CI] 176-264), infant mortality 94 per 1000 (95% CI 73-115), and perinatal mortality 52 per 1000 (95% CI 41-63). By prospective registration of morbidity, post-mortem interviews, and examination of available hospital records, a presumptive cause of death was established in 86% of the deaths. Persistent and acute diarrhoea were the most frequent causes of death, accounting for 43 and 31 deaths per 1000 children, respectively. Fever deaths (possibly malaria), neonatal deaths, acute respiratory infections, and measles were other frequent causes. The access to health services was relatively easy: 75% of the children who died had attended for treatment at a hospital or a health centre. It is important to find ways of preventing and managing persistent diarrhoea, the major cause of death, and to improve the control of acute diarrhoea by a targeted approach.     

Estimating the causes of 4 million neonatal deaths in the year 2000

BACKGROUND: Information on cause-of-death is lacking for 98% of the world's 4 million neonatal deaths that occur in countries with inadequate vital registration (VR). Our aim was to estimate, by country for the year 2000, the distribution of neonatal deaths across programme-relevant causes including: asphyxia, preterm birth, congenital abnormalities, sepsis/pneumonia, neonatal tetanus, diarrhoea, and 'other'. METHODS: Two sources of neonatal cause-of-death data were examined: VR datasets for countries with high coverage (>90%), and published and unpublished studies identified through systematic searches. Multinomial regression was used to model the distribution of neonatal deaths. A VR-based model was used to estimate the distribution of causes of death for 37 low-mortality countries without national data. A study-based model was applied to obtain estimates for 111 high-mortality countries. Uncertainty estimates were derived using the jackknife approach. RESULTS: Data from 44 countries with VR (96 797 neonatal deaths) and from 56 studies (29 countries, 13 685 neonatal deaths) met inclusion criteria. The distribution of reported causes of death varied substantially between countries and across studies. Based on 193 countries, the major causes of neonatal death globally were estimated to be infections (sepsis/pneumonia, tetanus, and diarrhoea, 35%), preterm birth (28%), and asphyxia (23%). Regional variation is important. Substantial uncertainty surrounds these estimates. CONCLUSIONS: This exercise highlights the lack of reliable cause-of-death data in the settings in which most neonatal deaths occur. Complex statistical models are not a panacea. Representative data with comparable case definitions and consistent hierarchical cause-of-death attribution are required.     

Malnutrition as an underlying cause of childhood deaths associated with infectious diseases in developing countries

INTRODUCTION: Recent estimates suggest that malnutrition (measured as poor anthropometric status) is associated with about 50% of all deaths among children. Although the association between malnutrition and all-cause mortality is well documented, the malnutrition-related risk of death associated with specific diseases is less well described. We reviewed published literature to examine the evidence for a relation between malnutrition and child mortality from diarrhoea, acute respiratory illness, malaria and measles, conditions that account for over 50% of deaths in children worldwide. METHODS: MEDLINE was searched for suitable review articles and original reports of community-based and hospital-based studies. Findings from cohort studies and case-control studies were reviewed and summarized. RESULTS: The strongest and most consistent relation between malnutrition and an increased risk of death was observed for diarrhoea and acute respiratory infection. The evidence, although limited, also suggests a potentially increased risk for death from malaria. A less consistent association was observed between nutritional status and death from measles. Although some hospital-based studies and case-control studies reported an increased risk of mortality from measles, few community-based studies reported any association. DISCUSSION: The risk of malnutrition-related mortality seems to vary for different diseases. These findings have important implications for the evaluation of nutritional intervention programmes and child survival programmes being implemented in settings with different disease profiles.     

Undernutrition as an underlying cause of child deaths associated with diarrhea, pneumonia, malaria, and measles

BACKGROUND: Previous analyses derived the relative risk (RR) of dying as a result of low weight-for-age and calculated the proportion of child deaths worldwide attributable to underweight. OBJECTIVES: The objectives were to examine whether the risk of dying because of underweight varies by cause of death and to estimate the fraction of deaths by cause attributable to underweight. DESIGN: Data were obtained from investigators of 10 cohort studies with both weight-for-age category (<-3 SDs, -3 to <-2 SDs, -2 to <-1 SD, and >-1 SD) and cause of death information. All 10 studies contributed information on weight-for-age and risk of diarrhea, pneumonia, and all-cause mortality; however, only 6 studies contributed information on deaths because of measles, and only 3 studies contributed information on deaths because of malaria or fever. With use of weighted random effects models, we related the log mortality rate by cause and anthropometric status in each study to derive cause-specific RRs of dying because of undernutrition. Prevalences of each weight-for-age category were obtained from analyses of 310 national nutrition surveys. With use of the RR and prevalence information, we then calculated the fraction of deaths by cause attributable to undernutrition. RESULTS: The RR of mortality because of low weight-for-age was elevated for each cause of death and for all-cause mortality. Overall, 52.5% of all deaths in young children were attributable to undernutrition, varying from 44.8% for deaths because of measles to 60.7% for deaths because of diarrhea. CONCLUSION: A significant proportion of deaths in young children worldwide is attributable to low weight-for-age, and efforts to reduce malnutrition should be a policy priority.     

Estimating child mortality due to diarrhoea in developing countries

OBJECTIVE: The major objective of this study is to provide estimates of diarrhoea mortality at country, regional and global level by employing the Child Health Epidemiology Reference Group (CHERG) standard. METHODS: A systematic and comprehensive literature review was undertaken of all studies published since 1980 reporting under-5 diarrhoea mortality. Information was collected on characteristics of each study and its population. A regression model was used to relate these characteristics to proportional mortality from diarrhoea and to predict its distribution in national populations. FINDINGS: Global deaths from diarrhoea of children aged less than 5 years were estimated at 1.87 million (95% confidence interval, CI: 1.56-2.19), approximately 19% of total child deaths. WHO African and South-East Asia Regions combined contain 78% (1.46 million) of all diarrhoea deaths occurring among children in the developing world; 73% of these deaths are concentrated in just 15 developing countries. CONCLUSION: Planning and evaluation of interventions to control diarrhoea deaths and to reduce under-5 mortality is obstructed by the lack of a system that regularly generates cause-of-death information. The methods used here provide country-level estimates that constitute alternative information for planning in settings without adequate data.     

Incidence and risk factors for Malaria, pneumonia and diarrhea in children under 5 in UNHCR refugee camps: A retrospective study

Background

United Nations High Commissioner for Refugees (UNHCR) refugee camps are located predominantly in rural areas of Africa and Asia in protracted or post-emergency contexts. Recognizing the importance of malaria, pneumonia and diarrheal diseases as major causes of child morbidity and mortality in refugee camps, we analyzed data from the UNHCR Health Information System (HIS) to estimate incidence and risk factors for these diseases in refugee children younger than five years of age.

Methods

Data from 90 UNHCR camps in 16 countries, including morbidity, mortality, health services and refugee health status, were obtained from the UNHCR HIS for the period January 2006 to February 2010. Monthly camp-level data were aggregated to yearly estimates for analysis and stratified by location in Africa (including Yemen) or Asia. Poisson regression models with random effects were constructed to identify factors associated with malaria, pneumonia and diarrheal diseases. Spatial patterns in the incidence of malaria, pneumonia and diarrheal diseases were mapped to identify regional heterogeneities.

Results

Malaria and pneumonia were the two most common causes of mortality, with confirmed malaria and pneumonia each accounting for 20% of child deaths. Suspected and confirmed malaria accounted for 23% of child morbidity and pneumonia accounted for 17% of child morbidity. Diarrheal diseases were the cause of 7% of deaths and 10% of morbidity in children under five. Mean under-five incidence rates across all refugee camps by region were: malaria [Africa 84.7 cases/1000 U5 population/month (95% CI 67.5-102.0), Asia 2.2/1000/month (95% CI 1.4-3.0)]; pneumonia [Africa 59.2/1000/month (95% CI 49.8-68.7), Asia 254.5/1000/month (95% CI 207.1-301.8)]; and diarrheal disease [Africa 35.5/1000/month (95% CI 28.7-42.4), Asia 69.2/1000/month (95% CI 61.0-77.5)]. Measles was infrequent and accounted for a small proportion of child morbidity (503 cases, < 1%) and mortality (6 deaths, < 1%).

Conclusions

As in stable settings, pneumonia and diarrhea are important causes of mortality among refugee children. Malaria remains a significant cause of child mortality in refugee camps in Africa and will need to be addressed as part of regional malaria control and elimination efforts. Little is known of neonatal morbidity and mortality in refugee settings, and neonatal deaths are likely to be under-reported. Global measles control efforts have reduced the incidence of measles among refugee children.     

No cry at birth: global estimates of intrapartum stillbirths and intrapartum-related neonatal deaths

OBJECTIVE: Fewer than 3% of 4 million annual neonatal deaths occur in countries with reliable vital registration (VR) data. Global estimates for asphyxia-related neonatal deaths vary from 0.7 to 1.2 million. Estimates for intrapartum stillbirths are not available. We aimed to estimate the numbers of intrapartum-related neonatal deaths and intrapartum stillbirths in the year 2000. METHODS: Sources of data on neonatal death included: vital registration (VR) data on neonatal death from countries with full (> 90%) VR coverage (48 countries, n = 97,297); studies identified through literature searches (> 4000 abstracts) and meeting inclusion criteria (46 populations, 30 countries, n = 12,355). A regression model was fitted to cause-specific proportionate mortality data from VR and the literature. Predicted cause-specific proportions were applied to the number of neonatal deaths by country, and summed to a global total. Intrapartum stillbirths were estimated using median cause-specific mortality rate by country (73 populations, 52 countries, n = 46,779) or the subregional median in the absence of country data. FINDINGS: Intrapartum-related neonatal deaths were estimated at 0.904 million (uncertainty 0.65-1.17), equivalent to 23% of the global total of 4 million neonatal deaths. Country-level model predictions compared well with population-based data sets not included in the input data. An estimated 1.02 million intrapartum stillbirths (0.66-1.48 million) occur annually, comprising 26% of global stillbirths. CONCLUSION: Intrapartum-related neonatal deaths account for almost 10% of deaths in children aged under 5 years. Intrapartum stillbirths are a huge and invisible problem, but are potentially preventable. Programmatic attention and improved information are required.     

Myanmar mortality registration: an assessment for system improvement

Background

The vital registration system in Myanmar has a long history and geographical coverage is currently high. However, a recent assessment of vital registration systems of 148 countries showed poor performance of the death registration system in Myanmar, suggesting the need for improvement. This study assessed the quality of mortality data generated from the vital registration system with regard to mortality levels and patterns, quality of cause of death data, and completeness of death registration in order to identify areas for improvement.

Methods

The study used registered deaths in 2013 from the vital registration system, data from the 2014 Myanmar Population and Housing Census, and mortality indicators and COD information for the country estimated by international organizations. The study applied the guidelines recommended by AbouZahr et al. 2010 to assess mortality levels and patterns and quality of cause of death data. The completeness of death registration was assessed by a simple calculation based on the estimated number of deaths.

Results

Findings suggested that the completeness of death registration was critically low (less than 60%). The under-registration was more severe in rural areas, in states and regions with difficult transportation and poor accessibility to health centers and for infant and child deaths. The quality of cause of death information was poor, with possible over-reporting of non-communicable disease codes and a high proportion of ill-defined causes of death (22.3% of total deaths).

Conclusion

The results indicated that the vital registration system in Myanmar does not produce reliable mortality statistics. In response to monitoring mortalities as mandated by the Sustainable Development Goals, a significant and sustained government commitment and investment in strengthening the vital registration system in Myanmar is recommended.

     

Contemporary patterns of Pacific Island mortality

BACKGROUND: The Pacific Island countries are at different stages of the demographic and epidemiological transitions. The availability of accurate and current mortality data is of vital importance for priority setting in health. Available mortality data generally underestimate death rates among both children and adults. In many Pacific Island populations, little is reliably known about levels and causes of death, particularly among adults. METHODS: The results of two comprehensive approaches to obtaining mortality estimates are reported. First, a systematic review of available life expectancy and infant mortality information reported by countries from 1990 onwards was undertaken and evaluated with respect to quality, and a final "best estimate" was established. Methods were based on registered deaths and indirect demographic methods. The second approach consisted of a demographic evaluation of vital registration data for completeness, with death rates adjusted accordingly, or where vital registration was not available, the application of new model life table methods to generate life tables from estimates of child mortality, as used by the World Health Organisation (WHO). RESULTS: This analysis reveals substantial uncertainty about mortality conditions in Pacific Island populations. In some countries, life expectancy variations of 10 years or more were recorded in the 1990s, depending on the source. Best approaches suggest that life expectancy (at birth) varied considerably, from levels of around 55-60 years in some Melanesian and Micronesian states to levels above 70 years in low-mortality countries. The principal issues with regard to uncertainty around mortality levels include underenumerated vital registration data; annual stochastic fluctuations in mortality in small populations; errors in the imputation of adult mortality from infant and childhood rates; implausible results from indirect demographic methods; use of possibly inappropriate model life tables to adjust death data or for indirect methods; and inadequately described and implausible projections. The WHO model life table method based on adjusted vital registration generally yielded results similar to those suggested by an evaluation of published data, with some exceptions, which are further discussed. CONCLUSIONS: This study indicates the urgent need to improve infrastructure, training, and resources for routine mortality estimation in many Pacific Island countries in order to better inform and evaluate health and public policy.     

Compiling mortality statistics from civil registration systems in Viet Nam: the long road ahead

Accurate mortality statistics, needed for population health assessment, health policy and research, are best derived from data in vital registration systems. However, mortality statistics from vital registration systems are not available for several countries including Viet Nam. We used a mixed methods case study approach to assess vital registration operations in 2006 in three provinces in Viet Nam (Hòa Bình, Thùa Thiên–Hué and Bình Duong), and provide recommendations to strengthen vital registration systems in the country. For each province we developed life tables from population and mortality data compiled by sex and age group. Demographic methods were used to estimate completeness of death registration as an indicator of vital registration performance. Qualitative methods (document review, key informant interviews and focus group discussions) were used to assess administrative, technical and societal aspects of vital registration systems. Completeness of death registration was low in all three provinces. Problems were identified with the legal framework for registration of early neonatal deaths and deaths of temporary residents or migrants. The system does not conform to international standards for reporting cause of death or for recording detailed statistics by age, sex and cause of death. Capacity-building along with an intersectoral coordination committee involving the Ministries of Justice and Health and the General Statistics Office would improve the vital registration system, especially with regard to procedures for death registration. There appears to be strong political support for sentinel surveillance systems to generate reliable mortality statistics in Viet Nam.     

Maternal mortality in a rural district of southeastern Tanzania: an application of the sisterhood method

BACKGROUND: Deaths from maternal causes represent the leading cause of death among women of reproductive age in most developing countries. It is estimated that the highest risk occurs in Africa, with 20% of world births but 40% of the world maternal deaths. The level of maternal mortality is difficult to assess especially in countries without an adequate vital registration system. Indirect techniques are an attractive cost-effective tool to provide estimates of orders of magnitude for maternal mortality. METHOD: The level of maternal mortality estimated by the sisterhood method is presented for a rural district in the Morogoro Region of Southeastern Tanzania and the main causes of maternal death are studied. Information from region-specific data using the sisterhood method is compared to data from other sources. RESULTS: The maternal mortality ratio (MMR) was 448 maternal deaths per 100,000 live births (95%CI : 363-534 deaths per 100,000 live births). Maternal causes accounted for 19% of total mortality in this age group. One in 39 women who survive until reproductive age will die before age 50 due to maternal causes. The main cause of death provided by hospital data was puerperal sepsis (35%) and postpartum haemorrhage (17%); this is compatible with the main causes reported for maternal death in settings with high levels of maternal mortality, and similar to data for other regions in Tanzania. The sisterhood method provides data comparable with others, together with a cost-effective and reliable estimate for the determination of the magnitude of maternal mortality in the rural Kilombero District.     

Global and regional cause-of-death patterns in 1990.

Demographic estimation techniques suggest that worldwide about 50 million deaths occur each year, of which about 39 million are in the developing countries. In countries with adequate registration of vital statistics, the age at death and the cause can be reliably determined. Only about 30-35% of all deaths are captured by vital registration (excluding sample registration schemes); for the remainder, cause-of-death estimation procedures are required. Indirect methods which model the cause-of-death structure as a function of the level of mortality can provide reasonable estimates for broad cause-of-death groups. Such methods are generally unreliable for more specific causes. In this case, estimates can be constructed from community-level mortality surveillance systems or from epidemiological evidence on specific diseases. Some check on the plausibility of the estimates is possible in view of the hierarchical structure of cause-of-death lists and the well-known age-specific patterns of diseases and injuries. The results of applying these methods to estimate the cause of death for over 120 diseases or injuries, by age, sex and region, are described. The estimates have been derived in order to calculate the years of life lost due to premature death, one of the two components of overall disability-adjusted life years (DALYs) calculated for the 1993 World development report. Previous attempts at cause-of-death estimation have been limited to a few diseases only, with little age-specific detail. The estimates reported in detail here should serve as a useful reference for further public health research to support the determination of health sector priorities.     

The burden of malaria mortality among African children in the year 2000

BACKGROUND: Although malaria is a leading cause of child deaths, few well-documented estimates of its direct and indirect burden exist. Our objective was to estimate the number of deaths directly attributable to malaria among children <5 years old in sub-Saharan Africa for the year 2000. METHODS: We divided the population into six sub-populations and, using results of studies identified in a literature review, estimated a malaria mortality rate for each sub-population. Malaria deaths were estimated by multiplying each sub-population by its corresponding rate. Sensitivity analyses were performed to assess the impact of varying key assumptions. RESULTS: The literature review identified 31 studies from 14 countries in middle Africa and 17 studies and reports from four countries in southern Africa. In 2000, we estimated that approximately 100 million children lived in areas where malaria transmission occurs and that 803 620 (precision estimate: 705 821-901 418) children died from the direct effects of malaria. For all of sub-Saharan Africa, including populations not exposed to malaria, malaria accounted for 18.0% (precision estimate: 15.8-20.2%) of child deaths. These estimates were sensitive to extreme assumptions about the causes of deaths with no known cause. CONCLUSIONS: These estimates, based on the best available data and methods, clearly demonstrate malaria's enormous mortality burden. We emphasize that these estimates are an approximation with many limitations and that the estimates do not account for malaria's large indirect burden. We describe information needs that, if filled, might improve the validity of future estimates.     

Causes of death: an assessment of global patterns of mortality around 1985

Cause-of-death statistics are available for virtually the entire population of the developed world (1.17 billion in 1985) and thus estimates of the mortality pattern in these countries can be made with some confidence, notwithstanding the artefacts which arise due to differences in diagnostic and certification practices between countries. In the developing countries, cause-of-death estimation is much more difficult due to the paucity of mortality statistics. Nonetheless, there are several sources of information on mortality, ranging from surveillance systems and small-scale community studies to complete vital registration, which can be exploited to estimate mortality patterns. Of the 50 million deaths which occur throughout the world each year, roughly 39 million (78%) occur in developing countries. For the developing countries as a whole, infectious and parasitic diseases are estimated to have accounted for almost one-half of all deaths in 1985. Diarrhoeal diseases, acute respiratory diseases (primarily pneumonia) and tuberculosis each claimed about 3-5 million deaths in the developing world in the mid-1980s, with a further 2.6 million due to measles and whooping cough. Perinatal conditions are estimated to have been responsible for a little over 3.2 million deaths in 1985 in developing countries, one-quarter of which were due to neonatal tetanus alone. Maternal causes claimed the lives of about 0.5 million women. At the same time, the chronic diseases are emerging as a leading cause of death in several regions of the developing world, particularly Latin America and East Asia. Circulatory and specific degenerative diseases are estimated to have caused about 6.5 million deaths in 1985. Chronic lung diseases and cancer are each thought to have claimed about 2.5 million lives in 1985. External causes also probably accounted for 2.0-2.5 million deaths.     

Needs in vital and health statistics in underdeveloped countries

The author discusses the types of health and vital statistics that would be of the greatest practical value to countries with only slightly developed public-health and vital registration systems and the ways by which these statistics may be obtained.While a regular census is necessary for proper mortality and natality statistics, population estimates may be successfully used until a census can be taken. Natality statistics should include live-births, stillbirths, legitimacy, and age of mother. For morbidity measurement, four sources of information or types of inquiry can be used before complete registration systems are available: sickness surveys by home visits of families; records of notifiable communicable diseases; medical records of sickness in schools; and records of health welfare centres and health visitors, when these exist. The use of infant mortality figures in underdeveloped countries is subject to considerable error, and great effort will be needed to get every living child in the birth register. A useful local index of health is the recording in selected areas of deaths during the first three years of life. Death-rates at higher ages can only be assessed where death registration is fairly complete.It is suggested that reliable information on population changes, child mortality and sickness, and the incidence of disease can be obtained by a continuous study programme in carefully selected model survey and registration districts. Apart from the immediate results from such a programme, it would prepare the ground for the subsequent establishment of a full vital registration system.     

Estimating mortality using data from civil registration: a cross-sectional study in India

ObjectiveTo analyse the design and operational status of India’s civil registration and vital statistics system and facilitate the system’s development into an accurate and reliable source of mortality data.MethodsWe assessed the national civil registration and vital statistics system’s legal framework, administrative structure and design through document review. We did a cross-sectional study for the year 2013 at national level and in Punjab state to assess the quality of the system’s mortality data through analyses of life tables and investigation of the completeness of death registration and the proportion of deaths assigned ill-defined causes. We interviewed registrars, medical officers and coders in Punjab state to assess their knowledge and practice.FindingsAlthough we found the legal framework and system design to be appropriate, data collection was based on complex intersectoral collaborations at state and local level and the collected data were found to be of poor quality. The registration data were inadequate for a robust estimate of mortality at national level. A medically certified cause of death was only recorded for 965 992 (16.8%) of the 5 735 082 deaths registered.ConclusionThe data recorded by India’s civil registration and vital statistics system in 2011 were incomplete. If improved, the system could be used to reliably estimate mortality. We recommend improving political support and intersectoral coordination, capacity building, computerization and state-level initiatives to ensure that every death is registered and that reliable causes of death are recorded – at least within an adequate sample of registration units within each state.     

Validation of cause-of-death statistics in urban China

BACKGROUND: National vital registration systems are the principal source of cause specific mortality statistics, and require periodic validation to guide use of their outputs for health policy and programme purposes, and epidemiological research. We report results from a validation of cause of death statistics from health facilities in urban China. METHODS: 2917 deaths from health facilities located in six cities in China constituted the study sample. A reference diagnosis of the underlying cause was derived for each death, based on expert review of available medical records, and compared with that filed at registration. Sensitivity, specificity and positive predictive value were computed for specific causes/cause categories according to the International Classification of Diseases (ICD), including analyses based on quality of evidence scores for each cause. Patterns of misclassification by the registration system were studied for individual causes of death. RESULTS: The registration system had good sensitivity in diagnosing cerebrovascular disease and several site specific cancers (lung, liver, stomach, colorectal, breast and pancreas). Sensitivity was average (50-75%) for some major causes of adult death in China, namely ischaemic heart disease (IHD), chronic obstructive lung disease (COPD), diabetes, and liver and kidney diseases, with compensatory misclassification patterns observed between several of them. Sensitivity was particularly low for hypertensive disease. CONCLUSIONS: Although diagnostic misclassification is not uncommon in urban death registration data, they appear to balance each other at the population level. Compensating misclassification errors suggest that caution is required when drawing conclusions about particular chronic causes of adult death in China. Investment is required to improve the quality of cause attribution for health facility deaths, and to assess the validity of cause attribution for home deaths. Periodic assessments of the quality of cause of death statistics will enhance their usability for health policy and epidemiological research.     

Mortality in the Islamic Republic of Iran, 1964-2004

OBJECTIVE: Reliable information on the pattern, level and trend of mortality is essential for evidence-based policy to improve health. Various sources of mortality data in the Islamic Republic of Iran have not been critically assessed. This paper aims to document and evaluate the completeness of the different data sources on mortality and to estimate the level and trends of mortality over the past 40 years according to various mortality indices such as child mortality, adult mortality and life expectancy. METHODS: We undertook a systematic review of all available studies on infant mortality from 1964 to 2004 and estimated the most probable trend in child mortality. Death registration data from between 1992 and 2004 were assessed for completeness to estimate the level of adult mortality. Life tables for 2004 were constructed for the Islamic Republic of Iran based on these data, corrected for under-registration of death. FINDINGS: Infant mortality decreased from an estimated 154 deaths per 1000 live births in 1964 to 26 in 2004. The risk of adult mortality in 2004 was estimated to be 0.124 and 0.175 for females and males respectively. According to adjusted death registration data, life expectancy at birth in 2004 was 71.2 for females and 68.7 for males. The average completeness of death registration for ages 5 years and older across all systems was 76% for the period 2001-2004. CONCLUSION: There has been a general decline in child mortality in the Islamic Republic of Iran over the past three decades. Adult mortality levels also have declined, but less substantially. Mortality information systems have improved, yet serious concerns remain regarding the completeness and quality of data.     

BCG vaccination scar associated with better childhood survival in Guinea-Bissau

BACKGROUND: Recent studies have suggested that Bacille Calmette-Guerin (BCG) vaccination may have a non-specific beneficial effect on infant survival and that a BCG scar may be associated with lower child mortality. No study has previously examined the influence of BCG vaccination on cause of death. METHODS: Two cohorts (A and B) were used to describe the mortality pattern for children with and without BCG scar and to determine specific causes of death. In cohort A (n = 1813), BCG scar was assessed at 6 months of age and as previously described children with a BCG scar had lower mortality over the next 12 months than children with no BCG scar. In cohort B, 1617 children aged 3 months to 5 years of age had their BCG scar status assessed in a household-based survey and mortality was assessed during a 12-month period. Causes of death were determined by verbal autopsy (VA) and related to BCG scar status in a cause-specific hazard function. RESULTS: Controlling for background factors associated with mortality, there was lower mortality for children with a BCG scar than without in cohort B, the mortality ratio (MR) being 0.45 (95% CI 0.21-0.96). Exclusion of children exposed to TB did not have any impact on the result. In a combined analysis of cohorts A and B, the MR was 0.43 (95% CI 0.28-0.65) controlling for background factors. There were no large differences in distribution of the five major causes of death (malaria, pneumonia, acute diarrhoea, chronic diarrhoea, and meningitis/encephalitis) according to BCG scar status in the two cohorts. Having a BCG scar significantly reduced the risk of death from malaria [MR 0.32 (95% CI 0.13-0.76)]. CONCLUSIONS: A BCG scar is a marker of better survival among children in countries with high child mortality. BCG vaccination may affect the response to several major infections including malaria.