A methodological note on the relationship between infant mortality and socioeconomic status with evidence from San Antonio, Texas.

A number of previous studies have concluded from social area analyses of medium-size cities that there is no longer a significant correlation between socioeconomic status (SES) and infant mortality in the U.S. To determine if these findings were an artifact of too small samples, the total, neonatal, and postneonatal infant mortality rates were analyzed for 115 census tracts of San Antonio, Texas. The SES of each tract was measured by a score reflecting equally the variables of income, education, and occupation, and allowed assignment of the tracts to 1 of 4 socioeconomic rankings. All 3 infant mortality rates rose as SES decreased, with the most marked relationship being between SES and postneonatal rates. It was also found that of the 3 variables used to measure SES, income bore the strongest relationship to infant mortality. In general it should be noted that social area analysis of infant mortality is limited by the extreme reductions of sample size when additional variables are induced.     

The relationship between socioeconomic status and infant mortality in metropolitan Ohio, 1999–2001

Abstract

Empirical evidence has consistently documented the direct relationship between infant mortality and socioeconomic inequality in the United States and numerous other countries. While the majority of these studies reveal an inverse relationship between socioeconomic level and infant mortality, not even this finding is free from disagreement. Furthermore, the specific nature and magnitude of this relationship has varied over time.

This study will examine the relationship between socioeconomic status and infant mortality in metropolitan Ohio by using birth and infant death data centered on the 2000 Census. The analyses presented herein will describe and analyze the relationship between infant mortality and socioeconomic status in metropolitan Ohio in the year 2000. The key finding is that in spite of remarkable declines in infant mortality during the past several decades, most notably in neonatal mortality, there continues to be a pronounced inverse association between the infant death rate and the economic status of a population.     

Racial differences in the relationship between infant mortality and socioeconomic status

This study presents an ecological analysis of the relationship between infant mortality and economic status by race in metropolitan Ohio, using census data on mother's residence and economic status determined by the percentage of low-income families living in each area. The analysis updates previous studies as white-non-white comparisons for total infant mortality are examined for the US censuses of 1960, 1970, 1980, 1990 and 2000; and more detailed period- and broad cause-specific rates are presented for 2000. A pronounced inverse association is consistently found between income status and infant mortality for whites, while for non-whites this pattern first emerges in 1979-81, disappears during the 1980s and then returns more strongly during the 1990s. Similarly, the 2000 data reveal a consistent inverse pattern between income status and infant mortality for white and non-white neonatal and postneonatal death rates, as well as exogenous cause-specific death rates. It is concluded that low-income whites and non-whites have infant mortality rates substantially higher than the overall rate for the population. Policy implications are discussed.     

Heredity counseling

Abstract

An ecological analysis of infant mortality rates is conducted using data on Texas counties for the years 1968–72. It is found that when counties along the Texas‐Mexico border (which have unreasonably low infant death rates and which are economically less advantaged than the remainder of the counties) are excluded from the analysis, the associations between socioeconomic status variables and infant mortality rates improve considerably. A significant negative correlation between neonatal mortality and per cent Spanish surname is retained and does not disappear when the effects of other relevant variables (per cent Negro, per cent urban, and per cent below poverty) are controlled using partial correlation and regression analysis. Possible explanations for this unexpected finding are suggested, and implications for further research are discussed.     

Relationships between pregnancy spacing,sex of infants,maternal age,and birth order,and neonatal and post‐neonatal mortality in Bangladesh

Abstract

The relationships between length of the interpregnancy interval, outcome of the pregnancy preceding the interval, sex of the infants, pregnancy order, maternal age, and maternal history of previous child deaths and neonatal and postneonatal mortality were explored in a rural Bangladeshi population using a multiple regression analysis. Specific interactions between the interpregnancy interval, outcome of the pregnancy preceding the interval, sex of the infants, and history of previous child deaths were examined. An inverse relationship was observed between postneonatal mortality and the length of the interpregnancy interval when the pregnancy preceding the interval was a surviving infant. No such trend was observed for neonatal mortality. Post‐neonatal mortality rates among children whose mothers had experienced two or more previous child deaths were essentially the same as that for infants whose mothers had experienced 0–1 child deaths when the interpregnancy intervals were more than 24 months. Although female infants have a lower neonatal mortality than male infants, the neonatal mortality rate for female infants conceived less than twelve months following a male infant birth was higher than for a male infant conceived less than twelve months following another male infant birth. Post‐neonatal mortality is consistently higher for female compared to male infants in all interval categories.     

Patterns and variations in the relationship between infant mortality and socioeconomic status

Abstract

This study utilizes an ecological approach based on census tracts of residence to examine the relationship between infant mortality and socioeconomic status in metropolitan Ohio at two points in time (1959–61 and 1969–71). The data presented clearly indicate that the infant mortality rate continues to exhibit a pronounced inverse association with a wide variety of socio‐economic variables. Although there were some notable exceptions and/or variations from the general patterns, a basic inverse relationship was generally found to be characteristic of both neonatal and postnatal components of infant mortality, for both males and females, and for both major exogenous and endogenous causes of death. Of all the variables examined, the one factor that emerged as the strongest and most consistent determinant of census tract variations in infant mortality was the proportion of low income families. Thus, the overriding conclusion suggested by this study is that in spite of such things as continued advances in medicine and public health, the expansion of a variety of social programs during the 1960's, and the recent resumption of a downward trend in the overall infant mortality rate, there has been little if any progress in achieving more equitable life chances for the economically deprived segments of our population.     

Socioeconomic development,medical care,and nutrition as determinants of infant mortality in less‐developed countries

Abstract

Using data for sixty less‐developed countries, we constructed a causal model in which medical care, nutrition, status of women, and socioeconomic development are examined as determinants of infant mortality. Social and economic development are treated as exogenous variables; medical care, nutrition, and status of women are viewed as variables endogenous to the model. The model is tested by maximum likelihood methods. Results indicate that good nutrition and the presence of informally trained health care personnel, i.e., midwives, are more significantly related to low rates of infant mortality than are the employment status of women and the presence of formally trained health care personnel such as physicians and nurses. The general level of social and economic development conditions these relationships.     

Sudden infant death syndrome and the age‐cause proxy relationship in infancy

Abstract

Evidence from a longitudinal study of the relationship between socioeconomic status and infant mortality in metropolitan Ohio is presented in an effort to throw additional light on the continuing debate over the validity of the age‐cause proxy relationship in infancy. The results indicate that while there is a fairly strong and consistent association between neonatal mortality and endogenous causes of death that is little affected by the classification of Sudden Infant Death Syndrome, the nature of the association between postneonatal mortality and exogenous causes of death varies from weak to moderate depending upon where this cause is included. Additional evidence pertaining to the role of SIDS in contributing to the long‐standing inverse association between infant mortality and socioeconomic status is presented, thus further emphasizing the need for continued research to clarify the etiologic mechanisms of this poorly understood condition.     

Ecological study of social fragmentation,poverty, and suicide

ObjectivesTo investigate the association between suicide and area based measures of deprivation and social fragmentation.DesignEcological study.Setting633 parliamentary constituencies of Great Britain as defined in 1991.ResultsMortality from suicide and all other causes increased with increasing Townsend deprivation score, social fragmentation score, and abstention from voting in all age and sex groups. Suicide mortality was most strongly related to social fragmentation, whereas deaths from other causes were more closely associated with Townsend score. Constituencies with absolute increases in social fragmentation and Townsend scores between 1981 and 1991 tended to have greater increases in suicide rates over the same period. The relation between change in social fragmentation and suicide was largely independent of Townsend score, whereas the association with Townsend score was generally reduced after adjustment for social fragmentation.ConclusionsSuicide rates are more strongly associated with measures of social fragmentation than with poverty at a constituency level.

Key messages

• Place of residence may affect health, and mortality from most common diseases tends to be higher in areas characterised by low socioeconomic position
• Research dating back over 100 years suggests that social fragmentation may influencesuicide
• In the 1980s and 1990s, parliamentary constituencies with high levels of social fragmentation had high rates of suicide, independent of deprivation
• Constituencies with the greatest increases in social fragmentation between 1981 and 1991 also had the greatest increases in suicide rates over the same period
• Any targeting of suicide prevention may be more effective if aimed at socially fragmented rather than deprived areas

     

Causes of death which contribute to the mortality crossover effect

Abstract

Death rates vary over the life cycle in a standard fashion, with mortality probabilities being highest at infant and older ages. Nevertheless, when age curves of mortality are compared for different populations, they sometimes can be seen to intersect so that one population has higher death rates at younger and middle ages and lower rates at older ages. Past research has shown that this phenomenon is not due to erroneous data and is probably a result of some type of selection in survival patterns. A sample of pairs of mortality curves, 31 of which cross over and 31 of which do not, for combinations of countries and dates are analyzed to discover which causes of death are associated with the crossover phenomenon at the older ages. Cardiovascular and “other and unknown” diseases appear to contribute strongly to the crossover effect. Further research should deal with other comparisons and explore the underlying social and environmental factors.     

Trends in undernutrition mortality among children under five years of age and adults over 60

Introduction: Children under five years of age living in poor areas and with low availability of healthy food have a higher risk of undernutrition-related mortality. However, this relationship has not been well established among older adults.Objective: To analyse socioeconomic inequality trends related to undernutrition mortality in children under five years of age and adults over 60 in Colombian municipalities during 2003-2009 and 2010-2016.Materials and methods: We conducted an ecological study of trends between 2003 and 2016. The study population consisted of children under five years of age and adults over 60 residing in the Colombian municipalities during the study period. We estimated smoothed and standardized mortality rates by fitting a hierarchical Bayesian model and explored their relationship with five socioeconomic area-level variables.Results: In most of the municipalities, undernutrition-related mortality was three times higher in older adults compared to children. Moreover, the difference in the risk of undernutrition-related mortality between municipalities showed a marked reduction. Finally, the poor and less developed municipalities had higher rates of undernutrition-related mortality in children; conversely, wealthier territories had higher rates in older adults.Conclusions: Although in most of the municipalities the mortality rates due to undernutrition in children under five and older adults have decreased, their socioeconomic conditions influence in different ways the risk of mortality for these two populations so there is the need to develop age-specific strategies to close social gaps considering the structural conditions of the areas.     

Breast‐feeding,social variables,and infant mortality: A hazards model analysis of the case of Malaysia

Abstract

This study is an attempt to use a hazards model to estimate the relative risks of mortality experienced at different periods during the first year of life among Malaysian infants breast‐fed for various durations. Data on mortality, breast‐feeding, and social variables were obtained from the retrospective Malaysian Family Life Survey and were used after checking for quality and consistency. Using LOGLIN to calculate hazards models, essentially multidimensional life‐tables, we found that breast‐feeding had an effect on mortality independent of socio‐economic variables and birth cohort. There was a monotonic relationship between breastfeeding duration and lower infant mortality during each of four subdivisions of the first year of life. Breast‐feeding was a statistically significant predictor of mortality in the first six months. The results are compared with those from the Rand study, which employed regression rather than hazards models.     

Heredity of joint diseases

Abstract

This research examines the infant mortality/socioeconomic status relationship in Toledo, Ohio, for the years centering around 19S0, 1960, and 1970 in order to depict variables that contributed most to infant mortality for each time period. Zero‐order correlation coefficients demonstrated that the relationship has widened mainly as a result of an increasing inverse neonatal/socioeconomic pattern which was due in part to a “cause‐period cross‐over effect” (exogenous causes of death were contributing to deaths in the neonatal period in 1970). Further examination suggested that the status variables through which the differentials were operating have shifted from one time period to another. In 1950, crowded housing conditions and unemployment were primarily responsible; in 1960, it was housing and income; and in 1970, marital instability and income predominated. This paper suggests that as new social phenomena emerge they quickly affect sensitive indicators of well‐being such as the infant mortality rate.     

Determinants of infant mortality and representation in bioarchaeological samples: A review

In bioarchaeological contexts, a complex relationship exists between infant representation in the age-at-death distribution, gestational and young child mortality rates, and the total fertility rate. The representation of infants in a skeletal sample may be influenced by a range of social, biological, and archaeological factors. To better understand the interactions between representation, fertility, and mortality, this study evaluates the relationship between infant-juvenile age-at-death proportions, fertility rates, and a range of gestational and early childhood mortality measures. The statistical component of this study found the correlation between fertility rates and infant-juvenile proportions was stronger than with any mortality rate variable of interest. This suggests that the proportion of infants in a mortuary sample is a stronger indicator of fertility than it is of infant-juvenile mortality. Social, biological, and archaeological variables potentially influencing infant representation in skeletal samples are discussed and a strongly contextualized and holistic approach to infant and juvenile mortality is recommended.     

Sex differentials in infant and child mortality in Korea

Abstract

This paper reports on a study of infant and child mortality in the Republic of Korea, a country known for a strong son preference, using the 1974 World Fertility Survey data. When the age‐specific probabilities of dying for ages zero to five are compared for male and female children, an unusual pattern of relatively high female mortality is observed. The higher female mortality is more pronounced during childhood than during infancy. Multivariate analysis of life tables, using a hazard model, shows that covariates influencing the mortality at young ages differ for male and female children and suggests that male and female children receive unequal care by their parents. The analysis also reveals different patterns of interaction between infant and child mortality and mother's fertility control behavior depending on the sex of the child.     

Blood group and behavioral differences among dizygotic twins: A failure to replicate

Abstract

The relationship between the age of mother and pregnancy outcome is examined using the matched birth‐infant death data for Arkansas. Indicators of pregnancy outcome are examined in relation to measures of SES and access to health care. The hypothesis that the elevated rate of newborn mortality and morbidity among infants delivered by adolescents as a consequence of biologic immaturity is examined. The analysis suggests that the higher levels of obstetric risk observed among teenage mothers is an artifact of lower SES and inferior access to health care and not biological immaturity as previously assumed.     

Mortality rate of Japanese twins: Infant deaths of twins after birth to one year of age

Abstract

In twin individuals born in Japan in the first half of 1974, rates of infant mortality up to one year of age were computed according to sex and order of birth. The rates were 5.50 per cent for males and 3.81 per cent for females. A lower mortality rate for first‐born twins indicates a reduced viability for second‐born twins, even in MZ twins. The effect of maternal age, gestational age, and birth weight on the rates of infant mortality were also analyzed.     

Socioeconomic development and mortality levels in less developed countries

Abstract

Some demographers have argued that post‐World War II mortality declines in the less‐developed countries (LDC's) are not associated with economic and social development because of the diffusion of health and medical techniques from the developed to the underdeveloped countries. This paper examines the current relationship between socioeconomic development and mortality levels in 124 countries, 94 of which are LDC's. The argument is tested with a path model consisting of five multidimensional and three unidimensional indicators. Results indicate that for the LDC's, there is a very strong set of direct and indirect relationships between indicators of socioeconomic development and mortality. Between 62 and 80 per cent of the variances in the crude death rate, infant mortality, and life expectancy are explained in the LDC model. The empirical test of the model demonstrates that lower mortality levels in the LDC's are dependent on socioeconomic factors and health services; continued improvement of socioeconomic levels in the LDC's will result in further mortality declines. For comparative purposes, the same model also is tested for more developed countries. Results for the model with more developed countries (MDC's) show that entirely different measures are necessary for MDC mortality models; the concept of “mortality” for LDC's and MDC's is orthogonal and requires different empirical indicators.     

A Social Gradient in Fatal Opioids and Cocaine Related Overdoses?

BackgroundTo determine the existence of a social gradient in fatal overdose cases related to non-prescribed opioids and cocaine use, recorded in Luxembourg between 1994 and 2011.MethodsOverdose cases were individually matched with four controls in a nested case-control study design, according to sex, year of birth, drug administration route and duration of drug use. The study sample, composed of 272 cases and 1,056 controls, was stratified according to a Social Inequality Accumulation Score (SIAS), based on educational attainment, employment, income, financial situation of subjects and the professional status of their father or legal guardian. Least squares linear regression analysis on overdose mortality rates and ridit scores were applied to determine the Relative Index of Inequality (RII) of the study sample.ResultsA negative linear relationship between the overdose mortality rate and the relative socioeconomic position was observed. We found a difference in mortality of 29.22 overdose deaths per 100 drug users in the lowest socioeconomic group compared to the most advantaged group. In terms of the Relative Inequality Index, the overdose mortality rate of opioid and cocaine users with lowest socioeconomic profiles was 9.88 times as high as that of their peers from the highest socioeconomic group (95% CI 6.49–13.26).ConclusionsOur findings suggest the existence of a marked social gradient in opioids and cocaine related overdose fatalities. Harm reduction services should integrate socially supportive offers, not only because of their general aim of social (re)integration but crucially in order to meet their most important objective, that is to reduce drug-related mortality.     

Women's status and infant mortality in rural Colombia

Abstract

This paper investigates the effects of maternal demographic characteristics and social and economic statuses on infant mortality in rural Colombia. Demographic characteristics include the age of the mother, parity and length of preceding interbirth interval, and sex of infant. Measures of women's status at the time of birth include education, wage labor and occupation, economic stratum, place of residence, and whether the mother is living with a husband. The life history data for the study (involving 4,928 births) were collected in 1986 from a representative sample of two cohorts of women resident in rural central Colombia. Overall diflFerentials in infant mortality by measures of women's status are small and are in good part associated with the differing reproductive behaviors of the women and variations in breastfeeding practices. The sharp declines in infant mortality recorded in rural Colombia in recent years appear less related to improved status of women than to reductions in fertility that enhance infant survivorship and to public health interventions shared by all segments of the population.