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Biomedical subjects

J Bongaarts

Publications and source records attributed to J Bongaarts.

At least 19 recordsLinked to original sources
PubMed2000

The potential role of contraception in reducing abortion.

This study examines the potential role of further increases in contraceptive prevalence and effectiveness in reducing abortion rates. The model used in this analysis links the abortion rate to its direct determinants, including couples' reproductive preferences, the prevalence and effectiveness of contraceptive practice to implement these preferences, and the probability of undergoing an abortion to avoid an unintended birth when a contraceptive fails or is not used. An assessment of the tradeoff between contraception and abortion yields estimates of the decline in the total abortion rate that would result from an illustrative increase of 10 percentage points in prevalence. This effect varies among societies, primarily because the tendency to obtain an abortion after an unintended pregnancy varies. For example, in a population with an abortion probability of 0.5, a 10 percentage-point increase in prevalence would avert approximately 0.45 abortions per woman, assuming contraception is 95 percent effective. If all unintended pregnancies were aborted, this effect would be three times larger. Eliminating all unintended pregnancies and subsequent abortions would require a rise in contraceptive prevalence to the level at which all fecund women who do not wish to become pregnant practice contraception that is 100 percent effective. A procedure is provided for estimating this "perfect" level of contraceptive prevalence.

Abortion, Induced↗
PubMed1999

The fertility impact of changes in the timing of childbearing in the developing world.

This study examines the role of tempo effects in the fertility declines of less developed countries. These effects temporarily inflate the total fertility of a population during periods when the age at childbearing declines and deflate it when childbearing is postponed. An analysis of data from the World Fertility Surveys and the Demographic and Health Surveys demonstrates that fertility trends observed in many less developed countries are likely to be distorted by changes in the timing of childbearing. In most countries women are delaying childbearing, which implies that observed fertility is lower than it would have been without tempo changes. This pattern is most clearly documented in Taiwan, where accurate birth statistics from a vital registration system make it possible to estimate the tempo components of fertility annually from 1978 to 1993. The small but unexpected rise in the total fertility of Colombia in the early 1990s is attributed to a decline in the negative tempo distortion that prevailed in the 1980s. Similar interruptions of ongoing fertility declines may occur in the future in other countries when existing negative tempo effects are removed.

Colombia↗
PubMed1997

Trends in unwanted childbearing in the developing world.

This study analyzes trends in unwanted fertility in 20 developing countries, based on data from the World Fertility Surveys and the Demographic and Health Surveys. Although wanted childbearing almost invariably declines as countries move through the fertility transition, the trend in unwanted fertility was found to have an inverted U shape. During the first half of the transition, unwanted fertility tends to rise, and it does not decline until near the end of the transition. This pattern is attributed to the combined effects of an increase in the duration of exposure to the risk of unwanted pregnancy and a rise in contraceptive use as desired family size declines. The substantial variation in unwanted fertility among countries at the same transition stage is caused by variation in the degree of implementation of preferences, the effectiveness of contraceptive use, the rate of induced abortion, and other proximate determinants, such as age at marriage, duration of breastfeeding, and frequency of sexual relations. The principal policy implication from this analysis is that vigorous efforts to reduce unwanted pregnancies through family planning programs and other measures are needed early in the fertility transition because, in their absence, unwanted fertility and abortion rates are likely to rise to high levels.

Abortion, Induced↗
PubMed1994

Population policy options in the developing world.

The population of the developing world is currently expanding at the unprecedented rate of more than 800 million per decade, and despite anticipated reductions in growth during the 21st century, its size is expected to increase from 4.3 billion today to 10.2 billion in 2100. Past efforts to curb this growth have almost exclusively focused on the implementation of family planning programs to provide contraceptive information, services, and supplies. These programs have been partially successful in reducing birth rates. Further investments in them will have an additional but limited impact on population growth; therefore, other policy options, in particular measures to reduce high demand for births and limit population momentum, are needed.

Contraception↗
PubMed1992

[Fertility preferences in Latin America: trends and differentials in seven countries].

The authors use Bongaarts's fertility preference measurement methodology to examine and compare changes in fertility preferences in Colombia, Costa Rica, the Dominican Republic, Ecuador, Jamaica, Peru, and Trinidad and Tobago over the period 1975-1989. "The trends of observed and desired fertility are examined at the national level and by level of education and rural-urban place of residence. The data used comes from fertility surveys....such as the World Fertility Survey (WFS) and the Demographic and Health Survey (DHS). The analysis suggests that the changes in fertility between the dates of the two surveys...are not due to changes in desired fertility, but mainly to differences in the degree to which fertility is controlled to coincide with desired levels.... Both the WFS and the DHS show that unwanted fertility was significant in all countries, specially in the lower socioeconomic strata." (SUMMARY IN ENG)

Americas↗
PubMed1991

Behavioural and biological determinants of fertility transition in sub-Saharan Africa.

In the transition from high to low fertility, different biological and behavioural proximate determinants play roles of varying importance in mediating the change. In most regions of the world, the practice of contraception has come to play the major role, so much so that there is a close relationship worldwide between the level of practice of contraception and the level of fertility. In sub-Saharan Africa, the prevalence of contraceptive practice is low, and fertility levels are exceptionally high for recorded levels of contraceptive practice, even where levels of contraceptive practice are comparable to other regions. The discrepancies are explained to a very large extent by differences between Africa and other regions in other proximate determinants--notably exposure to the risk of pregnancy, and abstinence after delivery. It would seem that transition in African countries will follow one of two patterns that are different to the pattern of transition observed in all other regions. First, fertility may rise before it declines, due to abandonment of traditional fertility regulation for some time prior to the eventual adoption of contraceptive practice. Second, the prevalence of contraceptive practice may rise for a time before there is an observable decline in fertility, because at the same time that contraception is adopted, traditional regulation of fertility is being abandoned, offsetting any effect on fertility. Kenya is an example of the first pattern, while Botswana, Ghana, and Zimbabwe are probably examples of the second.

Africa↗
PubMed1989

A model of the spread of HIV infection and the demographic impact of AIDS.

The objective of the computer simulation model described here is to project, for periods up to one or more decades, the annual incidence and prevalence of HIV infection and AIDS in a population with given epidemiological, behavioural and demorgraphic characteristics. In addition, the epidemic's impact on a range of demographic variables is calculated. The epidemiological components of the model use a compartmental approach and they are described with sets of linear differential equations. The demographic framework in which the epidemiological components are integrated, is based on a standard cohort component method of population projection. The simulated population is stratified by age, gender, sexual behaviour, marital status and infection/disease status. The concluding section provides an illustrative application of the model to a Central African population. In this hypothetical simulation covering the period from 1975 to 2000, HIV prevalence in the adult population rises from 0 to 21 per cent. By the end of the projection period mortality is about double the level that would have prevailed in the absence of the epidemic, but, owing to the very high birth rates that prevail in most of Africa, the growth rate of the population remains substantially positive.

Acquired Immunodeficiency Syndrome↗
PubMed1989

The relationship between male circumcision and HIV infection in African populations.

The relationship between HIV seroprevalence and the proportion of uncircumcised males in African countries is examined to determine whether circumcision practices play a role in explaining the large existing variation in the sizes of African HIV epidemics. A review of the anthropological literature yielded estimates of circumcision practices for 409 African ethnic groups from which corresponding national estimates were derived. HIV seroprevalence rates in the capital cities were used as indicators of the relative level of HIV infection of countries. The correlation between these two variables in 37 African countries was high (R = 0.9; P less than 0.001). This finding is consistent with existing clinic-based studies that indicate a lower risk of HIV infection among circumcised males.

Africa↗
PubMed1987

Fertility policy in China: future options.

A wide range of social, economic, and demographic criteria are used to evaluate China's present one-child policy and five alternative fertility policies that might guide China's population control efforts until the end of the century when the one-child policy is scheduled to be abandoned. These criteria include the policies' macrodemographic impact on total population size and population aging; their microdemographic effects on the family's ability to support the elderly, its economic capabilities, and the position of women; and their cultural acceptability to the majority Han Chinese population. The results suggest that the least desirable strategy is to retain the present policy; all the two-child alternatives perform better than the current one-child policy in achieving the policy goals considered.

Aging↗
PubMed1986

[Introduction of Goldstein therapies for disadvantaged clients in the Netherlands].

In Limburg, Netherlands, a project is going on aiming to implement lower class-linked skill-therapies into the regional mental health services. This article elucidates: the poor relationship that exists between contemporary psychotherapy and the lower class clients; various efforts that have been attempted to solve this problem; the basic elements of Goldstein's 'structured learning therapy'; activities and results of the Dutch 'Goldsteinproject'.

Assertiveness↗
PubMed1982

Repeat abortion in the United States: new insights.

The increasing numbers and proportions of repeat abortions in the United States, including higher order repeat abortions, can be adequately explained by the increasing numbers of women at risk and the heterogeneity of the population in regard to the need for and utilization of abortion services. The same factors, rather than a deterioration of contraceptive practice following abortion, explain the higher levels of repeat abortion rates compared with first abortion rates.

Abortion, Legal↗
PubMed1980

Does malnutrition affect fecundity? A summary of evidence.

Moderate chronic malnutrition has only a minor effect on fecundity (reproductive capacity), and the resulting effect on fertility (actural reproduction) is very small. Among the fecundity components examined here in noncontracepting populations, age at menarche and the duration of lactational amenorrhea appear to be the ones most affected by malnutrition. But from neither of those effects can a difference in fertility of more than a few percent be expected between poorly and well-nourished women in developing countries.

Abortion, Induced↗