The cocos-keeling islands: A demographic laboratory

The Cocos Islands, which are situated in the Indian Ocean approximately halfway between Colombo and Fremantle, were first peopled early in the nineteenth century and were gradually developed as a very isolated coconut plantation with a labour force consisting partly of persons of Malay stock descended from the original group of settlers and partly of Bantamese contract labourers from Java. As the Cocos-born population increased in size, the dependence on contract labour decreased and, before the end of the century, all immigration ceased. The 1947 Malay population of the islands was about 1,800.

The islands are fascinating from a demographer's point of view because there was a virtually complete registration of live births, deaths and marriages and a partial registration of stillbirths. With these registration records it was possible to construct the life history of every individual from birth, through infancy and childhood to marriage, and thence through fatherhood or motherhood to death.

The picture revealed by an analysis of these records is that of a population with very high fertility and with mortality at a high level before the first World war and at a medium level after that war. Crude birth rates varied between 50 and 60 per thousand population during the period 1888 to 1947. Crude death rates were between 30 and 40 per thousand population until 1912 but under 2.0 per thousand population after 1918.

Most Cocos girls married before reaching the age of 20 and there were an average of between eight and nine live births per woman living through the childbearing period. There was a steady decline in the average number of live births with advancing age at marriage from age 16 onwards. A significantly high proportion of those dying in the middle of the childbearing period had never married, but the fertility of those marrying at an early age (14, 15 and 16) and dying before reaching the age of 36 was slightly higher than that of those who married at a similar age and survived. Women who survived to the age of 55 were of higher fertility than those who died between the ages of 40 and 55. An analysis of birth intervals revealed significant differences (a) between birth intervals after a stillbirth or after a live birth in which the child died in early infancy, and birth intervals after a live birth in which the offspring survived for longer than 0.4 years, and (b) between the interval from first to second birth and the subsequent birth intervals. There was a difference of almost exactly a year between the average birth interval after a stillbirth or live birth ending in a neo-natal death and the average birth interval after the birth of a child surviving to age 2; there was a similar difference of a year between corresponding median birth intervals.

From 1888 to 1912 infant mortality was well above 300 per thousand. After 1918 infant mortality averaged rather under 100 infant deaths per 1,000 live births. The reduction in infant mortality rates was accompanied by an increase in the mortality of children aged 1 to 4, and the heavy incidence of mortality at these ages after 1918 is the most striking feature of the analysis of mortality by age. Whilst mortality in infancy fell much more heavily on males than on females, early childhood mortality was much higher in Cocos for girls than for boys. The life table computed for the period 1918 to 1947 indicated a life expectancy of about 50 years for males and 47 years for females.     

Socioeconomic Inequalities in Infant Mortality in Egypt: Analyzing Trends Between 1995 and 2014

This paper analyses the trend of the socioeconomic inequalities in infant mortality rates in Egypt over the period 1995–2014, using repeated cross-sectional data from the National Demographic and Health Survey. A multivariate logistic regression and concentration indices are used to examine the demographic and socioeconomic correlates of infant mortality, and how the degree of socioeconomic disparities in child mortality rates has evolved over time. We find a significant drop in infant mortality rates from 63 deaths per 1000 live births in 1995 to 22 deaths per 1000 live births in 2014. However, analyzing trends over the study period reveals no corresponding progress in narrowing the socioeconomic disparities in childhood mortality. Infant mortality rates remain higher in rural areas and among low-income families than the national average. Results show an inverse association between infant mortality rates and living standard measures, with the poor bearing the largest burden of early child mortality. Though the estimated concentration indices show a decline in the degree of socioeconomic inequality in child mortality rates over time, infant mortality rate among the poor remains twice the rate of the richest wealth quintile. Nonetheless, this decline in the degree of socioeconomic inequality in child mortality is not supported by the results of the multivariate logistic regression model. Results of the logistic model show higher odds of infant mortality among rural households, children who are twins, households with risky birth intervals. We find no statistically significant association between infant mortality and child’s sex, access to safe water, mothers’ work, and mothers’ nutritional status. Infant mortality is negatively associated with household wealth and regular health care during pregnancy. Concerted effort and targeting intervention measures are still needed to reduce the degree of socioeconomic and regional inequalities in child health, including infant mortality, in Egypt.     

A note on some vital statistics of a primitive peasant community in Sierra Leone

In the course of some work in which a community of 1400 primitive Sierra Leone peasants were being re-examined at two-monthly intervals over a period of a year opportunity was taken to record births, deaths and pregnancies. A birth-rate of 32·9 (P.E. ± 3·27), and a death-rate of 38·4 (P.E. ± 3·52) per thousand per annum were obtained. The infant mortality rate was found to be 417 (P.E. · 48) per thousand live births, and the ratio of miscarriages and stillbirths to live births to be 22·9: 100. Since the community was small the figures are subject to a high statistical error, but they are offered because the data are believed to be accurate, and accurate vital statistics of primitive West African communities are practically non-existent.

The most interesting features in regard to deaths were that deaths in children aged 3 years or under accounted for almost half the total deaths at all ages, and that of these deaths in young children 38·5 % were attributed to an acute febrile illness.     

Neo-natal and post-neo-natal mortality in a rural area of Bangladesh

Abstract An analysis of neo-natal and post-neo-natal mortality in 132 villages (population of 117,000) of Matlab thana indicates the following: (i) Neo-natal deaths accounted for 60% of the infant mortality rate of 125. This proportion was unexpectedly high since previous research had maintained that in countries with infant mortality rates over 100, neo-natal deaths account for less than one-third of all infant deaths. Since the present findings on the proportions of neo-natal deaths correspond exactly with results from an earlier registration system in East Pakistan, it is suggested that the long-accepted proposition, 'less developed' areas are characterized by lower proportions of neo-natal deaths than 'more developed' areas, be re-examined. (2) The infant death rate accounts for 36% of all deaths in the population. If the infant death rate were reduced by half the result would be a decrease in the current crude death rate from 16 to 13. Although this reduction would appear to be small, in the context of a current high growth rate of 3% (from 1966-67 to 1968-69) it exerts a sizeable impact. For example, it would take a reduction of eight points in the crude birth rate of 46 just to achieve a growth rate 2·5% under these circumstances. Obviously, continued efforts in death control without an effective birth control programme will perpetuate high rates of growth. (3) Neo-natal and post-neo-natal mortality exhibited the -expected 'U' shaped pattern with parity, and generally varied as expected with age and family size, except in the oldest age group and largest family size where the risk was smaller than in the preceding groups. An explanation for these findings is presented, based on the effect that births to high-parity women with low child mortality have upon the total neo-natal and post-neo-natal mortality rates. It was found that these births exhibit a much lower mortality risk than births to women of comparable parities and higher child mortality, and that their numbers account for the lower risk to the births in the oldest age group and largest family size. It was concluded that women with a combination of high parity and low child mortality most probably represent a group with superior socio-economic and or health conditions which contribute to the lower risk of neo-natal and post-neo-natal death.     

Some aspects of the relationship between the levels of infant mortality and fertility in the ESCAP region

The death of a child within the first year of life is a crucial factor in fertility decisions in a developing country. The infant mortality rate gives a close, inverse indication of the socioeconomic conditions of a country. This paper presents studies by Brass, Rutherford, Chowdhury, Khan and Chen, Agrawal, Iskander and Jones, in summary/abstract form. It concludes that the probabilities of survival are poorer for births of older women and/or higher parities. Early child deaths may increase the total period of exposure to the risk of conception. A lower infant and child mortality norm calls for fewer births to meet the needs for survivors. Child replacement motivational response seems to be strongest with the birth immediately following a death event. Agrawal analyzed the interval between successive births of 1107 women of Patna, Pakistan, according to the age of mother and sex and fate of the previous child. He observed that if a child died shortly after its birth, often a new pregnancy began within a short interval. The interval between 2 consecutive live births when the previous child was male and alive was greater than when the previous child was female and alive. The interval between 2 births was reduced if the child died in infancy and specially if this was a male child.     

Which factors explain the decline in infant and child mortality in Matlab,Bangladesh?

Infant and child mortality rates have decreased substantially in Matlab, Bangladesh, as they have in many developing areas. We use data from the Matlab Demographic Surveillance System on nearly 94,000 singleton live births that occurred between 1987 and 2002 to investigate the extent to which the change in mortality over this period can be explained by changes in reproductive patterns and socio-economic characteristics. We estimate Cox proportional hazards models for four subperiods of infancy and childhood. Changes over time in reproductive patterns (maternal age, parity, and pregnancy spacing) and in the socio-economic characteristics we consider (e.g. maternal education, SES) explain between 10 and 40% of the decline in mortality rates. Changes in maternal education explain the largest portion of the reduction in infant and child mortality over time that we are able to explain, followed by reductions in the incidence of short interpregnancy intervals. In the other direction, decreases in fertility over time led to increases in the proportion of births that were first births, putting upward pressure on mortality.

Social determinants of low birth weight in a high-risk population

Over ninety low-weight infants were born per thousand live births in South Carolina, based on 96,000 birth records from 1975 and 1979. Higher incidence of low birth weight for black infants cannot be explained away as a result of black/white differences in age or education of mothers, prenatal care, parity or length of birth intervals. Though all these factors are important predictors of birth weight, an increasing propensity to have low-weight babies persists among black mothers even after all these factors are controlled.     

Estimates of vital rates for the Canadian Indians, 1960–1970

The present paper is an attempt to evaluate the registered data on Canadian Indians collected by the Department of Indian Affairs and Northern Development and to prepare vital rates for 1960–1970 using the adjusted data. A cursory examination of registered data for the purpose of developing various demographic indices and for making future estimates of population indicates certain anomalies that call for a careful appraisal of the data. The main problem is the inconsistency in the reporting of births, due largely to the late registration of births. One plausible reason for late registration may be the increased outward movement of Indians from their reserves. Indirect methods are used to adjust the number of births and infant deaths reported annually since 1960. On the basis of the adjusted data, vital rates for the Canadian Indians are calculated for the period 1960–1970. The crude death rate decreased from 10.9 in 1960 to 7.5 in 1970. The infant mortality rate registered a drastic decline, from 81.5 deaths per 1,000 births in 1960 to 34.9 in 1970. During this same time period the birth rate also declined, from 46.5 to 37.2.     

Estimating the completeness of under-5 death registration in Egypt

To evaluate the completeness of registration of infant and child deaths in Egypt, reinterviews were conducted with families who had reported a death of a child under age 5 in the five years before the survey for two national surveys recently conducted in Egypt: the United Nations PAPCHILD survey of1990-1991 and the Egyptian Demographic and Health Survey (EDHS) of 1992. The survey instrument included questions regarding notification of the death at the local health bureau. If the family said the death had been notified, separate employees searched the health bureau records for the registration. Overall 57% of infant deaths were reported as notified and 68% of those death reports were found; the corresponding figuresfor child deaths were 89% and 74%. Using the percentage reported as notified as an estimate for completeness of registration, we adjusted upward the national infant and child mortality rates from registration data, giving values of 73 per 1,000 for infant mortality and 99 for ₅q₀ for the period 1987-1990. These values are approximately 20% above the corresponding direct estimates from the PAPCHILD and EDHS surveys.     

Reproductive mortality in Georgia: A lifestyle and environmental analysis

Frequencies and rates of maternal mortality in the United States have declined sharply since the turn of the century. During this decline, researchers have closely examined maternal mortality relative to various risk factors. However, maternal death as currently defined and coded on death certificates may not reveal the true extent of the problem of reproductive mortality. In Georgia, an analysis of death certificates of females ages 10 to 49 indicates that deaths due to pregnancy related conditions are not being discovered by traditional underlying cause-of-death maternal mortality classification. Frequencies and rates were calculated showing the difference between the traditional International Classification of Disease codes for maternal deaths (ICD 630–676) and the reproductive mortality definition used in this paper (which emphasizes the Health Field Concept classification of Lifestyle, Environment, Biology and Health Care Delivery System) (Lalonde, M., 1974 and Laframboise, H. L., 1973). The analysis suggests that a revised definition of maternal mortality be employed to take into consideration all risk factors related to reproductive mortality.     

India's National Family Health Survey provides new information on maternal and child health and AIDS awareness

Teams surveyed a sample of 88,562 households, drawn from 99% of the population of India in 24 states plus the National Capital Territory of Delhi, between April 1992 and September 1993 to collect a basic set of information on all 500,492 household members, with more details on the 89,777 women in the households who had ever been married and were aged 13-49 years. This National Family Health Survey (NFHS) collected information from the women on a range of health topics including child immunization, women's knowledge of AIDS, services and facilities use during pregnancy and childbirth, infant feeding and treatment for diarrhea, and infant, child, and maternal mortality. Levels of infant and child mortality declined in India, but 8% of all children still die before their first birthday and 11% die before reaching age 5. As for maternal mortality, there are an estimated 420 maternal deaths per 100,000 live births annually. That rate implies that at least 100,000 Indian women die each year due to causes related to pregnancy and childbirth. Survey results indicate the need to strengthen vaccination programs and teach women about proper infant feeding practices. They also highlight the need to increase antenatal care and other medical services. In all of these areas, the NFHS results indicate wide variation among India's regions and states. Furthermore, a general lack of AIDS awareness suggests that the government's AIDS awareness campaign, relying primarily upon electronic media, has not yet reached the majority of India's population.     

Infant mortality in the Marshall Islands

Levy and Booth present previously unpublished infant mortality rates for the Marshall Islands. They use an indirect method to estimate infant mortality from the 1973 and 1980 censuses, then apply indirect and direct methods of estimation to data from the Marshall Islands Women's Health Survey of 1985. Comparing the results with estimates of infant mortality obtained from vital registration data enables them to estimate the extent of underregistration of infant deaths. The authors conclude that 1973 census appears to be the most valid information source. Direct estimates from the Women's Health Survey data suggest that infant mortality has increased since 1970-1974, whereas the indirect estimates indicate a decreasing trend in infant mortality rates, converging with the direct estimates in more recent years. In view of increased efforts to improve maternal and child health in the mid-1970s, the decreasing trend is plausible. It is impossible to estimate accurately infant mortality in the Marshall Islands during 1980-1984 from the available data. Estimates based on registration data for 1975-1979 are at least 40% too low. The authors speculate that the estimate of 33 deaths per 1000 live births obtained from registration data for 1984 is 40-50% too low. In round figures, a value of 60 deaths per 1000 may be taken as the final estimate for 1980-1984.     

Emigration and fertility decline: The case of Barbados

This paper examines the role of emigration in the recent fertility declines which have occurred on the island of Barbados. Barbados with a history of over two centuries of out-migration has experienced in the period 1951–1970 very significant migration loss. In the period 1960–1970 and up to the present fertility has been declining. An important question is what part has this net migration loss of 32,600 had on the reduction of the crude birth rate from 33.6 in 1960 or from 31.5 in 1956 to 20.5 in 1970? Using officially published net migration loss figures and supplementing them with data on Barbadians living overseas, we calculated the crude birth rates which would have occurred had there been no migration loss. We also calculated the numbers of births to be expected if certain age-specific fertility rates were maintained and compared these with the births to residents plus the calculated births to Barbadians overseas. We conclude that in both cases emigration is a very significant contributor to the fertility declines which have occurred and are still underway.     

Annual mortality rates and excess deaths of children under five in Iraq, 1991-98

Data from two parallel household surveys conducted in Iraq by UNICEF in 1999 show that under-5 mortality declined steadily from 1974 to 1990, reaching about 63 per 1,000 live births in the period 1986-90. It then rose dramatically to 118 per 1,000 in 1991, the year of the Gulf War. The number of 'excess' under-5 deaths (i.e., the number in excess of the number predicted from past trends) in Iraq between 1991 and 1998 was calculated assuming that, instead of the rates measured by the 1999 survey for this period, either (a) average mortality rates for the period 1986-90 had been maintained, or (b) mortality had continued to decline at the rate observed between 1974 and 1990. According to these calculations, the estimated number of excess deaths resulting from the Gulf War and its aftermath up to 1998 was between 400,000 (assumption a) and 500,000 (assumption b).     

An evaluation of brass mortality estimates under conditions of declining mortality

An evaluation of the Brass childhood mortality estimates under conditions of declining mortality shows them to overestimate current mortality. Error increases as the rate of mortality decline increases, as the childhood age up to which cumulative mortality is being estimated increases, and as age at onset of childbearing decreases. We use the results to develop a method for correcting the Brass estimates for the effects of quasistability. The method requires an estimate of the rate of mortality decline within the population in addition to information on the pattern of childbearing in the population.     

Revising Infant Mortality Rates for the Early Twentieth Century United States

Accurate vital statistics are required to understand the evolution of racial disparities in infant health and the causes of rapid secular decline in infant mortality during the early twentieth century. Unfortunately, U.S. infant mortality rates prior to 1950 suffer from an upward bias stemming from a severe underregistration of births. At one extreme, African American births in southern states went unregistered at the rate of 15 % to 25 %. In this study, we construct improved estimates of births and infant mortality in the United States for 1915–1940 using recently released complete count decennial census microdata combined with the counts of infant deaths from published sources. We check the veracity of our estimates with a major birth registration study completed in conjunction with the 1940 decennial census and find that the largest adjustments occur in states with less-complete birth registration systems. An additional advantage of our census-based estimation method is the extension backward of the birth and infant mortality series for years prior to published estimates of registered births, enabling previously impossible comparisons and estimations. Finally, we show that underregistration can bias effect estimates even in a panel setting with specifications that include location fixed effects and place-specific linear time trends.     

A problem in measuring infant mortality]

Infant mortality rates refer to the number of infant deaths in a given calendar year divided by the total number of births for the same year. It is argued that this definition presents a logical problem, such that if "infant" is defined as any child less than 1 year old, then the set of criteria for infants born in January of the given calendar year is totally different for that of infants born in December. Due to the tremendous significance of infant mortality rates in assessing the socioeconomic growth of a given area, discrepancies such as the problem presented cannot be easily overlooked, particularly where small populations are concerned. A more accurate yet problematic approach for small populations, i.e., calculating the rate of infant mortality based on infant birthdays, using proposed linear regression scheme is presented.     

Estimation of vital rates by means of monte carlo simulation

Monte Carlo simulation has been used to estimate age-specific fertility and mortality rates for a small population,the French-derived isolate of Northside on St. Thomas, U. S. Virgin Islands. Estimates were based on data collected in a household census and genealogical survey and on birth, death, and marriage records for the years 1916to 1966. During this 50-year period (in which the population size increased from 202 to 657), the numbers of births and deaths were too, small to estimate age-specific rates directly, and in addition, death registration was incomplete. Mortality rates were estimated using a simulation program in which mortality was the only stochastic variable. A model mortality schedule was chosen which most accurately reproduced the growth pattern of the population over the 50-year period. To estimate fertility rates, a more complex simulation model was used in which fertility, nuptiality, and mortality were random variables with probability distributions. Preliminary estimates of fertility were made from the birth records and used as input to this simulation program. Birth probabilities were adjusted empirically from one set of simulation runs to the next, until population growth rates, as well as other demographic characteristics, were similar in the real and simulated populations. The birth rates which produced the best fit to the real population data were taken as the estimated age-specific fertility schedule. To reproduce the real population age structure more closely, secular changes in birth probabilities were applied.     

The Effect of Imputation Procedures on First Birth Intervals: Evidence from Five African Fertility Surveys

In most African societies there is little motivation to remember dates of demographic events with the level of precision required in demographic surveys. Consequently it is common that the large majority of survey respondents can provide only the calendar year of occurrence or their age at the time of the event. The World Fertility Survey Group decided to handle the problem of poor date reporting by using a computer program to impute the missing information. This article illustrates the effect of these imputation procedures on cross-national differentials in the proportion of premarital first births in Benin, Cameroon, Cote d’Ivoire, Ghana, and Nigeria. The analysis demonstrates that the exceptionally low proportion of premarital first births in Ghana is an artifact of the imputation procedures.     

The effect of the Great Blackout of 1965 on births in New York City

A comparison of the number of births in New York City nine months after the Great Blackout of 1965 with comparable periods for the previous five years shows no increase in births associated with the blackout.