THE SPATIAL RELATIONSHIP BETWEEN INFANT MORTALITY AND BIRTH DEFECT RATES IN A U.S. CITY

The spatial patterns of infant mortality and birth defect rates in the Des Moines, Iowa, urban region are described as a contoured surface based on the punctual kriging of address-matched vital statistics records from The Iowa Department of Public Health. Areas defined as having high rates are shown to be sensitive to the size of the spatial filtering units. There is no correlation between infant mortality and birth defect rates in the region. The significance of areas with high rates is determined by a Monte Carlo simulation procedure. One area of high infant mortality is found in the region, which contrasts with many smaller areas with high birth defect rates in the region. The observed birth defect rate pattern is consistent with the hypothesis that each birth was equally likely to result in a birth defect, while the infant mortality pattern is unlikely to be the result of such an equal likelihood process.     

Intra-urban variations of neonatal and post-neonatal mortality in a developing city

Numerous surveys at the national and regional level have demonstrated that large inequalities in infant health status exist in Southern Africa. Few studies have assessed infant mortality at the intra-urban scale of geographic analysis. Comparisons between infant mortality rates from different areas are made even more meaningful if the data are divided into two primary categories based on period-of-death; these being the neonatal and post-neonatal components. This study presents the results of a survey undertaken in Metropolitan Cape Town (population 1.6 million) during 1982. The aim was to determine the spatial variation of neonatal and post-neonatal mortality at the suburb (or community) level within the city. Overall, a total of 36,789 live births and 928 infant deaths were recorded; 53.4% in the neonatal period and 46.6% in the post-neonatal period. The mean infant mortality rate was 25.2 per 1000 live births; the neonatal mortality rate and post-neonatal mortality rate being 13.5/1000 and 11.7/1000, respectively. A marked range in death rates was evident for both components. For the neonatal category it was 0.0-49.9/1000 and 0.0-40.0/1000 for the post-neonatal period. The generally low post-neonatal mortality rate among the 69 suburbs studied has made the neonatal component the dominant contributor to the infant mortality rate. However, in the lowest socio-economic areas the post-neonatal mortality rate was responsible for over 60% of infant deaths.(ABSTRACT TRUNCATED AT 250 WORDS)     

The perinatal and infant health status of Native Hawaiians.

Hawaii vital record data for 1979 through 1990 were analyzed to examine potentially differing relationships between maternal and infant risks and outcomes in native Hawaiian and White infants. Despite high rates of inadequate prenatal care and teenage and unmarried childbearing, the Hawaiian low-birth-weight rate was below the US average. Hawaiian infants experienced an elevated risk of mortality, particularly among those of normal birthweight during the postneonatal period. Public health initiatives to reduce infant mortality must go beyond preventing teenage pregnancy and low birthweight to address Hawaiian infants' unique pattern of risk factors and the social and economic environment in which such risks abound.     

Patterns of infant mortality and cancer death in Alabama, USA

Aim  To use recent information of infant and cancer mortality in Alabama counties of the USA to test their relationships with social, economic, and environmental conditions at a large scale to identify potential public health issues. Subjects and methods  The data of infant mortality rates and cancer deaths in the recent years, biodiversity, including species number of plants, fishes, reptiles, and amphibians, roadless areas, metropolitan areas, river basins, African-American and minority populations, and per person income for all 67 Alabama counties were obtained and organized by geographic information system. The relationships between infant mortality rates and cancer deaths and social, economic, and environmental conditions at a large scale were analyzed. Results  Infant mortality was significantly higher in African-American and other minority populations than in white populations, but cancer mortality was higher in white populations than in African-American and minority populations. There was no significant difference in infant mortality rate between populations in the urban areas and the rural areas, but the mortality rate of cancers was significantly higher in the rural population than in the urban population. Mortality rates for cancers in wealthy counties were lower than in poorer counties. The incidences of infant and cancer mortality were lower in counties with higher biodiversity. The emergent spatial pattern suggests that the incidences of infant and cancer mortality were higher in the Sipsey/Warrior River Basin, Coosa/Tallapoosa River Basin, and Conecuh River Basins. Conclusion  This study indicates that ethnic disparities in infant and cancer mortality still exist in Alabama. This study also suggests that pattern analyses at larger scales can provide new insight for understanding public health.     

Infant mortality Social inequality in a Swedish city

Infant mortality rates for geographical areas of Göteborg(Gothenburg), Sweden, were studied for 78,357 infants livingin Göteborg from 1971 to 1985. During this time 637 infantdeaths occurred. The 32 parishes of Göteborg were dividedinto three groups referred to as high, medium and low incomeareas. The difference in infant mortality among the areas wasstatistically significant and increased over time. The relativerisk of Infant death was 1.8 in the medium and 2.0 in the lowcompared to the high income areas in 1981–1985. The infantmortality rate varied from 3.8 to 7.6/1000. The high incomeareas had lower death rates overall, in congenital malformationsand in perinatal conditions. The low income areas had a significantlyhigher rate of sudden infant death syndrome than the other groups.Political and administrative decentralization was implementedin Sweden in the 1980s. Local area research thus has a directrelevance for policy, planning and provision of services. Theresults reflect the social segregation, associated not onlywith economic stratification but also with differences in lifestylesand cultural environment. Further analyses are necessary toprovide Information on preventable risk factors In order todecrease the observed socio-economic differences. The resultscan, however, be used for targeting infant mortality levelsand for the allocation of resources.     

The estimation of mortality for ethnic groups at local scale within the United Kingdom

As an input to projections of sub-national populations by ethnicity, this paper develops the first estimates of the mortality risks experienced by the UK ethnic groups. Two estimates were developed using alternative methods. In the first, UK 2001 Census data on limiting long-term illness to predict mortality levels and regression equations between local Standardized Illness and Mortality Ratios for all ethnicities are assumed to apply to individual ethnic groups. In the second, the geographical distribution of ethnic groups by local areas is combined with local mortality for all ethnicities to estimate national mortality rates by ethnicity, which are then employed to estimate local ethnic mortality. A comparison of the two estimates indicates that the method based on illness rates produces more plausible outcomes. The local SMRs produced for each ethnic group were used to generate ethnic group life tables for 432 UK local authority areas in 2001, which included estimates of survivorship probabilities by single year of age, gender and ethnic group for each local area for use in a projection model.     

Spatio-temporal patterns of diarrhoeal mortality in Mexico

Diarrhoeal mortality rates in Mexican children dramatically declined during the 1980s and 1990s, concomitant with a temporal shift in peak deaths from summer to autumn-winter. The spatial dynamics of these patterns have not previously been studied. We first describe the seasonal features of paediatric diarrhoeal mortality in Mexico as a whole, then across individual states. While no geographical gradients in the magnitude of diarrhoeal mortality rates have been detected in recent years, we identified a distinct spatial pattern in the timing of peak mortality rate. In the 1980s the summer peak mortality was earliest around Mexico's capital and later in states to the southeast and northwest. Our results suggest that the direction and timing of those annual waves are related to the mean monthly precipitation and mean daily temperature. This pattern has disintegrated in recent years as the summer peak has diminished.     

The contribution of specific causes of death to mortality differences by marital status in the Netherlands

The purpose of this study was to describe the differences inmortality by marital status in the Netherlands in the period1986–1990 for specific causes of death and to estimatethe contribution of each specific cause to the differences intotal mortality. We have used mortality and population datafrom Statistics Netherlands. Poisson regression was used tocalculate relative risks of dying from the specific causes ofdeath. The relative risks and the overall mortality rates wereused to estimate the contribution of the specific causes ofdeath to the differences in total mortality by marital status.For men the general pattern was that the divorced had the highestrisks, followed by the never-married and that the widowed hadrisks closest to married men. For women the general patternwas that the divorced had the highest risks, while widowed andnever-married women alternately had risks closest to marriedwomen. Important exceptions to these risk patterns were foundfor, among others, infectious and parasitic diseases among menand breast cancer among women. External causes of death in particular,contributed more to the excess mortality of the 3 unmarriedgroups of men and women than expected, while the contributionsof malignant neoplasms and diseases of the circulatory systemwere lower than expected on the basis of the percentages ofthese causes of death in mortality in the married population.Since the causes of death that contributed disproportionatelyto the excess mortality of the unmarried almost all have unhealthylifestyles as important risk factors, we argue that the majorityof the mortality differences by marital status can be explainedby social causation (marital status affects health through lifestyledifferences). However, longitudinal data are necessary to ruleout selection effects (effect of health on marital status),preferably controlling for sociodemographic confounders suchas socioeconomic status and taking into account living arrangements.     

Hospital system as a source of information to estimate stillbirth and neonatal mortality rates

OBJECTIVE: Studies on the evolution of infant mortality rate are very relevant. Nevertheless, lack of vital statistics in Brazil limits the temporal and spatial analysis of this indicator. This study aims to investigate the possible use of the Brazilian Hospital Information System as an alternative information source for stillbirth and neonatal mortality rates by age group. METHODS: A new method to estimate the stillbirth and neonatal mortality rates is proposed. It was applied in a set of selected Brazilian states in the year of 1995. For comparative purposes, the Brazilian Death Information System was assessed to estimate the mortality rates under study, after adjusting the registered number of live births by using a demographic tool. RESULTS: By assessing the Hospital Information System a larger number of fetal and early neonatal deaths were observed when compared to data given by the death information system of the Northeastern states. Besides, in the Southern and Southeastern states, where death records are more thorough, the mortality rates calculated using both information sources were very similar. CONCLUSIONS: The results suggest that the proposed methodology could greatly contribute to the analysis of the spatial-time evolution of stillbirth and neonatal death rates in recent years in Brazil, as data on death registration in the majority of the Brazilian states are less thorough than those from the hospital information system.     

Spatio-temporal interaction with disease mapping

Markov chain Monte Carlo methods are used to estimate mortality rates under a Bayesian hierarchical model. Spatial correlations are introduced to examine spatial effects relative to both regional and regional changes over time by groups. A special feature of the models is the inclusion of longitudinal variables which will describe temporal trends in mortality or incidences for different population groups. Disease maps are used to illustrate the role of different parameters in the model and pinpointing areas of interesting patterns. The methods are demonstrated by male cancer mortality data from the state of Missouri during 1973-1992. Of special interest will be the geographic variations in the trend of lung cancer mortality over the recent past. Marginal posterior distributions are used to examine effects due to spatial correlations and age difference in temporal trends. Numerical results from the Missouri data show that although spatial correlations exist, they do not have a large effect on the estimated mortality rates.     

Exceptions to the rule: healthy deprived areas and unhealthy wealthy areas

In general, inhabitants of low socio-economic areas are unhealthier than inhabitants of high socio-economic areas, but some areas are an exception to this rule. These exceptions imply that other factors besides the socio-economic level of an area contribute to the health of the inhabitants of an area, e.g. environmental factors. In our study we concentrate on areas within the Netherlands that are healthier or unhealthier than could be expected based on their socio-economic level. This study first identifies these areas and secondly determines which area characteristics distinguish these areas from those areas where the level of health is in agreement with their socio-economic level. We used nation-wide data on neighbourhood differences in population composition (gender, age, marital status and ethnicity), urbanisation and two health indicators: mortality and hospitalisation rates. In the Netherlands, many areas are healthier or unhealthier than could be expected based on their income level alone. Areas with higher mortality rates than expected are mainly urban areas with high percentages of elderly people and persons living alone. Similar but opposite associations are observed for areas with lower mortality rates than expected, which are further characterised by a low percentage of non-western immigrants. Areas with lower hospitalisation rates than expected are mainly rural areas with few non-western immigrants. From these results, we conclude that urbanisation and residential segregation based on age, ethnicity and marital status might be important contributors to geographical health inequalities.     

No fathers' names: a risk factor for infant mortality in the State of Georgia, USA

Many studies have explored maternal and infant factors as risks for infant mortality, but little attention is given to paternal factors. In Georgia, listing a father's name on the birth certificate is optional for married couples and possible after paternal acknowledgment for unmarried couples. The authors evaluated father's name reporting as a paternity measure and risk for infant mortality. Using the linked 1989-1990 birth and death certificates of singleton Georgia infants to calculate relative risks (RRs), infant mortality rates for 38,943 infants with no father's names listed were compared to rates for 178,100 with father's names listed. Compared with the rate for married women listing names, the death rates were higher for unmarried mothers not listing fathers (relative risk, RR = 2.5; 95% CI 2.3-2.7), unmarried mothers listing fathers (RR = 1.4; 95% CI 1.3-1.6), and married women not listing fathers (RR = 2.3; 95% CI 1.6-3.1). Increased risks remained after stratifying by maternal race, age, adequacy of prenatal care and medical risks; and congenital malformations, birthweight, gestational age, and small-for-gestational age. Using logistic regression to examine for effect modification and to adjust for these factors together, the adjusted relative risks for death varied across different groups without fathers' names, regardless of marital status. For example, it remained statistically higher for infants with no father listed and without effect-modifying conditions such as low birthweight (estimated RR = 2.0; 95% CI 1.6-2.4). Although these findings suggest paternal involvement, as measured by listing fathers' names, is protective against low birthweight and infant mortality, further evaluation is needed.     

Cultural background and infant survival in Ghana

This study is premised on the hypothesis that ethnic specific socio-cultural practices such as dietary taboos and food avoidances on mothers and infants, as well as perceptions of disease aetiology and treatment patterns may be salient to understanding infant mortality differentials in Ghana. To inform policy, the paper explores if there are significant ethnic differences in infant survival, and whether such differences reflect socio-economic disparities or intrinsic factors. Using data from the 1998 Ghana Demographic and Health Survey, there was evidence of significant ethnic differences in infant survival at the bivariate level. Using Asante mothers as reference, the risk of death was significantly higher among children whose mothers were Mole-Dagbani, Grussi, Gruma, Dagarti, Fanti and Other Akan. In the multivariate models, however, the higher mortality risks associated with these children significantly attenuated after controlling for the socio-economic and bio-demographic factors except for the Fanti. The findings are discussed with reference to the characteristics and cultural theoretical paradigms.     

Spatial patterns of infant mortality in Mali: the effect of malaria endemicity

A spatial analysis was carried out to identify factors related to geographic differences in infant mortality risk in Mali by linking data from two spatially structured databases: the Demographic and Health Surveys of 1995-1996 and the Mapping Malaria Risk in Africa database for Mali. Socioeconomic factors measured directly at the individual level and site-specific malaria prevalence predicted for the Demographic and Health Surveys' locations by a spatial model fitted to the Mapping Malaria Risk in Africa database were examined as possible risk factors. The analysis was carried out by fitting a Bayesian hierarchical geostatistical logistic model to infant mortality risk, by Markov chain Monte Carlo simulation. It confirmed that mother's education, birth order and interval, infant's sex, residence, and mother's age at infant's birth had a strong impact on infant mortality risk in Mali. The residual spatial pattern of infant mortality showed a clear relation to well-known foci of malaria transmission, especially the inland delta of the Niger River. No effect of estimated parasite prevalence could be demonstrated. Possible explanations include confounding by unmeasured covariates and sparsity of the source malaria data. Spatial statistical models of malaria prevalence are useful for indicating approximate levels of endemicity over wide areas and, hence, for guiding intervention strategies. However, at points very remote from those sampled, it is important to consider prediction error.     

Geographic information systems as a tool for monitoring health inequalities]

OBJECTIVE: To show how geographic information systems (GISs) can be used as technological tools to support health policy and public health actions. METHODS: We assessed the relationship between infant mortality and a number of socio-economic and geographic determinants. In explaining how GISs are applied, we stressed their ability to integrate data, which makes it possible to perform epidemiologic evaluations in a simpler, faster, automated way that simultaneously analyzes multiple variables with different levels of aggregation. In this study, GISs were applied in analyzing infant mortality data with three levels of aggregation in countries of the Americas from 1995 to 2000. RESULTS: Infant mortality in the Region of the Americas was estimated at an overall average of 24.4 deaths per 1,000 live births. However, the inequalities that were found indicate that the probability of an infant death is almost 20 times greater in the less developed countries of the Region than in more developed ones. Mapping infant mortality throughout the Region of the Americas allowed us to identify the countries that need to focus more attention on health policy and health programs, but not to determine what specific actions are of the highest priority. An analysis of smaller geopolitical units (states and municipalities) revealed important differences within countries. This shows that, as is true of data for the entire Region of the Americas, using national-level average figures for indicators can obscure the differences that exist within countries. When we examined the relationship between female illiteracy and malnutrition as determinants of infant mortality in Brazil and Ecuador, we identified social and epidemiologic strata where risk factors had different distribution patterns and that thus require health interventions that match their individual social and epidemiologic profiles. CONCLUSIONS: With this type of epidemiologic study using GISs at the local level of health services, it is easy to see how a health event and its risk factors behave at a specific period in time. It is also possible to identify patterns in the spatial distribution of risk factors and in these factors' potential impact on health. Using GISs in an appropriate way will make it easier to deliver more effective, equitable public health services.     

Spatial patterns of fetal loss and infant death in an arsenic-affected area in Bangladesh

Background  

Arsenic exposure in pregnancy is associated with adverse pregnancy outcome and infant mortality. Knowledge of the spatial characteristics of the outcomes and their possible link to arsenic exposure are important for planning effective mitigation activities. The aim of this study was to identify spatial and spatiotemporal clustering of fetal loss and infant death, and spatial relationships between high and low clusters of fetal loss and infant death rates and high and low clusters of arsenic concentrations in tube-well water used for drinking.     

The Asian birth outcome gap

Asians are often considered a single group in epidemiological research. This study examines the extent of differences in maternal risks and birth outcomes for six Asian subgroups. Using linked birth/infant death certificate data from the State of California for the years 1992-97, we assessed maternal socio-economic risks and their effect on birthweight, preterm delivery (PTD), neonatal, post-neonatal and infant mortality for Filipino (87,120), Chinese (67,228), Vietnamese (45,237), Korean (23,431), Cambodian/Laotian (21,239) and Japanese (18,276) live singleton births. The analysis also included information about non-Hispanic whites and non-Hispanic blacks in order to give a sense of the magnitude of risks among Asians. Logistic regression models explored the effect of maternal risk factors and PTD on Asian subgroup differences in neonatal and post-neonatal mortality, using Japanese as the reference group. Across Asian subgroups, the differences ranged from 2.5- to 135-fold for maternal risks, and 2.2-fold for infant mortality rate. PTD was an important contributor to neonatal mortality differences. Maternal risk factors contributed to the disparities in post-neonatal mortality. Significant differences in perinatal health across Asian subgroups deserve ethnicity-specific interventions addressing PTD, teen pregnancy, maternal education, parity and access to prenatal care.     

Point pattern analysis with spatially varying covariate effects,applied to the study of cerebrovascular deaths

This article proposes a modeling approach for handling spatial heterogeneity present in the study of the geographical pattern of deaths due to cerebrovascular disease.The framework involvesa point pattern analysis with components exhibiting spatial variation. Preliminary studies indicate that mortality of this disease and the effect of relevant covariates do not exhibit uniform geographic distribution. Our model extends a previously proposed model in the literature that uses spatial and non‐spatial variables by allowing for spatial variation of the effect of non‐spatial covariates. A number of relative risk indicators are derived by comparing different covariate levels, different geographic locations, or both. The methodology is applied to the study of the geographical death pattern of cerebrovascular deaths in the city of Rio de Janeiro. The results compare well against existing alternatives, including fixed covariate effects. Our model is able to capture and highlight important data information that would not be noticed otherwise, providing information that is required for appropriate health decision‐making. Copyright © 2014 John Wiley & Sons, Ltd.     

Cardiovascular mortality focusing on socio-economic influence: the low-risk population of Halland compared to the population of Sweden as a whole

The aim of the study was to investigate the relationship between mortality from cardiovascular diseases (CVD) and socio-economic status (SES) in Sweden and to estimate to what extent the difference between a province with low mortality and the rest of Sweden was dependent on socio-economic factors. A population-based retrospective study with a historical prospective approach was performed covering a 10-y period in the province of Halland, Sweden, as well as Sweden as a whole. Altogether 1,654,744 men and 1,592,467 women were included, of whom 45,394 men and 43,403 women were from Halland, distributed according to SES. Multivariate analysis with Poisson regression was used. Relative risks with 95% confidence intervals were calculated. Both men and women with a low SES showed a significantly higher risk of death from CVD in Sweden as a whole. The risk was 23% higher for male blue-collar workers and 44% higher for female blue-collar workers when compared to their white-collar counterparts. The level of mortality in Halland was 14% lower compared to the country as a whole when only age was taken into account. When the socio-economic variable was also included, this figure was 8%. The results show the substantial significance of social differences with respect to CVD mortality. The effect of SES seems to be more important than that of geographical conditions when the latter are isolated from socio-economic influence.     

Stillbirth and infant mortality in singletons by cause of death,birthweight, gestational age and birthweight‐for‐gestation,Newcastle upon Tyne 1961–2000

Glinianaia SV, Rankin J, Pearce MS, Parker L, Pless‐Mulloli T. Stillbirth and infant mortality in singletons by cause of death, birthweight, gestational age and birthweight‐for‐gestation, Newcastle upon Tyne 1961–2000. Paediatric and Perinatal Epidemiology 2010. The dramatic reduction observed in stillbirth and infant mortality over the last few decades has not been assessed by both birthweight and gestation. We have explored temporal changes in stillbirth and infant mortality in Newcastle upon Tyne, UK, by cause of death, birthweight, gestational age, birthweight standardised for gestation and infant sex during 1961–2000. We included 131 044 singleton births to mothers resident in Newcastle, including 1342 stillbirths and 1620 infant deaths. Cause‐, birthweight‐, gestational age‐ and birthweight‐for‐gestation‐specific stillbirth (per 1000 total births) and infant mortality (per 1000 livebirths) rates were compared between 1961–80 and 1981–2000 and between individual consecutive decades. Between 1961 and 2000, total stillbirth and infant mortality rates declined dramatically from 23.4 to 4.7 per 1000 total births and from 25.7 to 5.9 per 1000 livebirths, respectively. Rates fell continuously during the first two study decades; however, from 1981–90 to 1991–2000 the decline was not statistically significant. Between 1961–80 and 1981–2000, both stillbirth and infant mortality significantly declined in all birthweight and gestational age categories and for most leading causes of death. Although the population mean birthweight during 1981–2000 [3304 g (SD ± 569)] was significantly higher than during 1961–80 [3255 g (SD ± 572)] (P < 0.0001), the lowest stillbirth and infant mortality rates in 1981–2000 were consistently at about 1 SD above the mean birthweight, with mortality rates increasing for babies with lower or higher weight‐for‐gestation. Declines in stillbirth and infant mortality in Newcastle were associated with reductions in birthweight‐ and gestational age‐specific mortality rates and occurred in most cause‐specific groups of death.