Kenneth Hill

Estimates of maternal mortality worldwide between 1990 and 2005: an assessment of available data

BACKGROUND Maternal mortality, as a largely avoidable cause of death, is an important focus of international development efforts, and a target for Millennium Development Goal (MDG) 5. However, data weaknesses have made monitoring progress problematic. In 2006, a new maternal mortality working group was established to develop improved estimation methods and make new estimates of maternal mortality for 2005, and to analyse trends in maternal mortality since 1990. METHODS We developed and used a range of methods, depending on the type of data available, to produce comparable country, regional, and global estimates of maternal mortality ratios for 2005 and to assess trends between 1990 and 2005. FINDINGS We estimate that there were 535,900 maternal deaths in 2005, corresponding to a maternal mortality ratio of 402 (uncertainty bounds 216-654) deaths per 100,000 livebirths. Most maternal deaths in 2005 were concentrated in sub-Saharan Africa (270,500, 50%) and Asia (240,600, 45%). For all countries with data, there was a decrease of 2.5% per year in the maternal mortality ratio between 1990 and 2005 (p<0.0001); however, there was no evidence of a significant reduction in maternal mortality ratios in sub-Saharan Africa in the same period. INTERPRETATION Although some regions have shown some progress since 1990 in reducing maternal deaths, maternal mortality ratios in sub-Saharan Africa have remained very high, with little evidence of improvement in the past 15 years. To achieve MDG5 targets by 2015 will require sustained and urgent emphasis on improved pregnancy and delivery care throughout the developing world.

Levels and trends in child mortality, 1990–2009

This article looks at the levels and trends in child mortality from 1990-2009. It tracks the progress that has been made in this area and states that removing financial and social barriers to accessing welfare services innovations to make supply of critical services more available to the poor and increasing local accountability of the health systems are examples of policy interventions that have allowed health systems to improve equity.

Stillbirth rates: delivering estimates in 190 countries

BACKGROUND While information about 4 million neonatal deaths worldwide is limited, even less information is available for stillbirths (babies born dead in the last 12 weeks of pregnancy) and there are no published, systematic global estimates. We sought to identify available data and use these to estimate the rates and numbers of stillbirths for 190 countries for the year 2000, and provide uncertainty estimates. METHODS We assessed three sources of stillbirth data according to specified inclusion criteria: vital registration; demographic and health surveys (DHS), based on a new analysis of contraceptive calendar data; and study reports that include published studies identified through systematic literature searches of more than 30,000 abstracts and unpublished studies. A random effects regression model was developed to predict national stillbirth rates and associated uncertainty intervals. FINDINGS Data from 44 countries with vital registration (71,442 stillbirths), 30 DHS surveys from 16 countries (2989 stillbirths), and 249 study populations from 103 countries (93,023 stillbirths) met the inclusion criteria. Model-based estimates were used for 128 countries. For 62 countries, the observed values were adjusted by a correction factor derived from the model. The resultant stillbirth rates ranged from five per 1000 in rich countries to 32 per 1000 in south Asia and sub-Saharan Africa. The estimated number of global stillbirths is 3.2 million (uncertainty range 2.5-4.1 million). In light of the data limitations and the conservative approach taken, the real number might be higher than this. INTERPRETATION The numbers of stillbirths are high and there is a dearth of usable data in countries and regions in which most stillbirths occur, with under-reporting being a major challenge. Although our estimates are probably underestimates, they represent a rigorous attempt to measure the numbers of babies dying during the last trimester of pregnancy. Improving stillbirth data is the first step towards making stillbirths count in public-health action.

Can we achieve Millennium Development Goal 4? New analysis of country trends and forecasts of under-5 mortality to 2015

BACKGROUND Global efforts have increased the accuracy and timeliness of estimates of under-5 mortality; however, these estimates fail to use all data available, do not use transparent and reproducible methods, do not distinguish predictions from measurements, and provide no indication of uncertainty around point estimates. We aimed to develop new reproducible methods and reanalyse existing data to elucidate detailed time trends. METHODS We merged available databases, added to them when possible, and then applied Loess regression to estimate past trends and forecast to 2015 for 172 countries. We developed uncertainty estimates based on different model specifications and estimated levels and trends in neonatal, post-neonatal, and childhood mortality. FINDINGS Global under-5 mortality has fallen from 110 (109-110) per 1000 in 1980 to 72 (70-74) per 1000 in 2005. Child deaths worldwide have decreased from 13.5 (13.4-13.6) million in 1980 to an estimated 9.7 (9.5-10.0) million in 2005. Global under-5 mortality is expected to decline by 27% from 1990 to 2015, substantially less than the target of Millennium Development Goal 4 (MDG4) of a 67% decrease. Several regions in Latin America, north Africa, the Middle East, Europe, and southeast Asia have had consistent annual rates of decline in excess of 4% over 35 years. Global progress on MDG4 is dominated by slow reductions in sub-Saharan Africa, which also has the slowest rates of decline in fertility. INTERPRETATION Globally, we are not doing a better job of reducing child mortality now than we were three decades ago. Further improvements in the quality and timeliness of child-mortality measurements should be possible by more fully using existing datasets and applying standard analytical strategies.

Association of Maternal Stature With Offspring Mortality, Underweight, and Stunting in Low- to Middle-Income Countries

CONTEXT Although maternal stature has been associated with offspring mortality and health, the extent to which this association is universal across developing countries is unclear. OBJECTIVE To examine the association between maternal stature and offspring mortality, underweight, stunting, and wasting in infancy and early childhood in 54 low- to middle-income countries. DESIGN, SETTING, AND PARTICIPANTS Analysis of 109 Demographic and Health Surveys in 54 countries conducted between 1991 and 2008. Study population consisted of a nationally representative cross-sectional sample of children aged 0 to 59 months born to mothers aged 15 to 49 years. Sample sizes were 2,661,519 (mortality), 587,096 (underweight), 558,347 (stunting), and 568,609 (wasting) children. MAIN OUTCOME MEASURES Likelihood of mortality, underweight, stunting, or wasting in children younger than 5 years. RESULTS The mean response rate across surveys in the mortality data set was 92.8%. In adjusted models, a 1-cm increase in maternal height was associated with a decreased risk of child mortality (absolute risk difference [ARD], 0.0014; relative risk [RR], 0.988; 95% confidence interval [CI], 0.987-0.988), underweight (ARD, 0.0068; RR, 0.968; 95% CI, 0.968-0.969), stunting (ARD, 0.0126; RR, 0.968; 95% CI, 0.967-0.968), and wasting (ARD, 0.0005; RR, 0.994; 95% CI, 0.993-0.995). Absolute risk of dying among children born to the tallest mothers (> or = 160 cm) was 0.073 (95% CI, 0.072-0.074) and to those born to the shortest mothers (< 145 cm) was 0.128 (95% CI, 0.126-0.130). Country-specific decrease in the risk for child mortality associated with a 1-cm increase in maternal height varied between 0.978 and 1.011, with the decreased risk being statistically significant in 46 of 54 countries (85%) (alpha = .05). CONCLUSION Among 54 low- to middle-income countries, maternal stature was inversely associated with offspring mortality, underweight, and stunting in infancy and childhood.

Characterizing the epidemiological transition in Mexico: national and subnational burden of diseases, injuries, and risk factors.

Background Rates of diseases and injuries and the effects of their risk factors can have substantial subnational heterogeneity, especially in middle-income countries like Mexico. Subnational analysis of the burden of diseases, injuries, and risk factors can improve characterization of the epidemiological transition and identify policy priorities. Methods and Findings We estimated deaths and loss of healthy life years (measured in disability-adjusted life years [DALYs]) in 2004 from a comprehensive list of diseases and injuries, and 16 major risk factors, by sex and age for Mexico and its states. Data sources included the vital statistics, national censuses, health examination surveys, and published epidemiological studies. Mortality statistics were adjusted for underreporting, misreporting of age at death, and for misclassification and incomparability of cause-of-death assignment. Nationally, noncommunicable diseases caused 75% of total deaths and 68% of total DALYs, with another 14% of deaths and 18% of DALYs caused by undernutrition and communicable, maternal, and perinatal diseases. The leading causes of death were ischemic heart disease, diabetes mellitus, cerebrovascular disease, liver cirrhosis, and road traffic injuries. High body mass index, high blood glucose, and alcohol use were the leading risk factors for disease burden, causing 5.1%, 5.0%, and 7.3% of total burden of disease, respectively. Mexico City had the lowest mortality rates (4.2 per 1,000) and the Southern region the highest (5.0 per 1,000); under-five mortality in the Southern region was nearly twice that of Mexico City. In the Southern region undernutrition and communicable, maternal, and perinatal diseases caused 23% of DALYs; in Chiapas, they caused 29% of DALYs. At the same time, the absolute rates of noncommunicable disease and injury burdens were highest in the Southern region (105 DALYs per 1,000 population versus 97 nationally for noncommunicable diseases; 22 versus 19 for injuries). Conclusions Mexico is at an advanced stage in the epidemiologic transition, with the majority of the disease and injury burden from noncommunicable diseases. A unique characteristic of the epidemiological transition in Mexico is that overweight and obesity, high blood glucose, and alcohol use are responsible for larger burden of disease than other noncommunicable disease risks such as tobacco smoking. The Southern region is least advanced in the epidemiological transition and suffers from the largest burden of ill health in all disease and injury groups.

The effect of water and sanitation on child health: evidence from the demographic and health surveys 1986–2007

BACKGROUND Despite continued national and international efforts, access to improved water and sanitation remains limited in many developing countries. The health consequences of lacking access to water and sanitation are severe, and particularly important for child development. METHODS To investigate the associations between child health and access to water and sanitation, we merged all available Demographic and Health Surveys (DHS) with complete birth histories and water and sanitation information. The merged data set of 171 surveys includes information on 1.1 million children under the age of 5 years in 70 low- and middle-income countries over the period 1986-2007. We used logistic models to estimate the effect of water and sanitation access on infant and child mortality, diarrhoea and stunting. RESULTS Access to improved sanitation was associated with lower mortality (OR = 0.77, 95% CI 0.68-0.86), a lower risk of child diarorhea (OR = 0.87, 95% CI 0.85-0.90) and a lower risk of mild or severe stunting (OR = 0.73, 95% CI 0.71-0.75). Access to improved water was associated with a lower risk of diarrhoea (OR = 0.91, 95% CI 0.88-0.94) and a lower risk of mild or severe stunting (OR = 0.92, 95% CI 0.89-0.94), but did not show any association with non-infant child mortality (OR = 0.97, 95% CI 0.88-1.04). CONCLUSIONS Although our point estimates indicate somewhat smaller protective effects than some of the estimates reported in the existing literature, the results presented in this article strongly underline the large health consequences of lacking access to water and sanitation for children aged <5 years in low- and middle-income countries.

Mortality in China 1964-2000

This paper uses data from censuses and surveys to re-estimate mortality levels and trends in China ,from the 1960s to 2000. We use the General Growth Balance method to evaluate the completeness of death reporting above the youngest ages in three censuses of the Peoples Republic of China from 1982 to 2000, concluding that reporting quality is quite high, and revisit the completeness of death recording in the 1973–75 Cancer Epidemiology Survey. Estimates of child mortality from a variety of direct and indirect sources are reviewed, and best estimates arrived at. Our estimates show a spectacular improvement in life expectancy in China: from about 60 years in the period 1964–82 to nearly 70 years in the period 1990–2000, with a further improvement to over 71 years by 2000. We discuss why survival rates continue improving in China despite reduced government involvement in and increasing privatization of health services, with little insurance coverage.

Interim measures for meeting needs for health sector data : births, deaths, and causes of death

Most developing countries do not have fully effective civil registration systems to provide necessary information about population health. Interim approaches—both innovative strategies for collection of data, and methods of assessment or estimation of these data—to fi ll the resulting information gaps have been developed and refined over the past four decades. To respond to the needs for data for births, deaths, and causes of death, data collection systems such as population censuses, sample vital registration systems, demographic surveillance sites, and internationally-coordinated sample survey programmes in combination with enhanced methods of assessment and analysis have been successfully implemented to complement civil registration systems. Methods of assessment and analysis of incomplete information or indirect indicators have also been improved, as have approaches to ascertainment of cause of death by verbal autopsy, disease modelling, and other strategies. Our knowledge of demography and descriptive epidemiology of populations in developing countries has been greatly increased by the widespread use of these interim approaches; although gaps remain, particularly for adult mortality. However,these approaches should not be regarded as substitutes for complete civil registration but rather as complements,essential parts of any fully comprehensive health information system. International organisations, national governments, and academia all have responsibilities in ensuring that data continue to be collected and that methods continue to be improved.

Further developments in indirect mortality estimation

Summary A variety of indirect estimators of mortality; survival of children by marriage duration of mother, survival of first spouse by marriage duration and by age, maternal orphanhood, and survival of siblings, are investigated by the use of a wide range of model fertility and mortality situations. Survival probabilities are then related by regression analysis to the proportions with a particular characteristic, to yield an equation which can then be used to estimate the survival probability in a population. Maternal orphanhood and survival of first spouse by age have already shown themselves to be useful, and the new developments are only simplifications of the existing methodology. Survival of first spouse by duration of marriage, and survival of siblings are, however, new methods which have yet to be justified by field experience. In conclusion, the features common to all indirect mortality estimation procedures are outlined, and the direction future developments may take in response to gradually improving data quality is suggested.