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Biomedical subjects

J Trussell

Publications and source records attributed to J Trussell.

At least 73 records · Page 4Linked to original sources

New female intravaginal barrier contraceptive device. Preliminary clinical trial.

The Fem Cap, a silicone rubber cervical cap, is shaped like a sailor's hat. While its dome covers the cervix, its rim fits snugly into the vaginal fornices, and its brim adheres and conforms to the vaginal walls. A spermicidal material is applied to the cap, then it is positioned over the cervix by hand or with a special applicator. The device is removed by hand up to 48 hours after insertion, but no sooner than eight hours after intercourse. Women chosen for the trial had contraindications to or were dissatisfied with the currently available contraceptive methods. Each woman was fitted with a cap of suitable size and instructed in its use. She was then asked to note any side effects and the dates of her menses in a diary. One-hundred-twenty-one women were enrolled in the study. Five became pregnant. Of those, two reported dislodgment of the cap during intercourse; the other three admitted to non-use of the cap on several occasions. This device has proven so far to be safe, effective and acceptable to women and men. It has several advantages over the currently available barrier contraceptive devices. The silicone rubber material from which it is made is non-allergenic, durable and easy to clean. Its design fits the anatomy and accommodates physiological changes. The Fem Cap is easy to insert and remove; an applicator facilitates insertion for some women. Instruction for use of the device requires short time from the health care provider.

Adolescent↗

Further analysis of contraceptive failure of the ovulation method.

Reanalysis of data on the ovulation method of natural family planning collected by the World Health Organization yields the following conclusions. The method is effective during perfect (correct and consistent) use, with a first-year probability of failure of 3.4%. However, it is extremely unforgiving of imperfect use, with a first-year probability of failure of 84.2% if the method is not used correctly. During the initial year, 87% of the cycles were characterized by perfect use. Nevertheless, the 13% of cycles characterized by imperfect use had a tremendous impact on the overall failure rate. During the first year of typical use 22.5% of the women in the clinical trial became accidentally pregnant.

Adult↗

A guide to interpreting contraceptive efficacy studies.

Results of trials of various birth control methods and contraceptive products may provide misleading data and engender unrealistic expectations regarding efficacy. An analysis of published efficacy-trials reveals numerous fallacies in their design, performance, and reporting. Consequently, family planning clinicians find it virtually impossible to make valid comparisons among the methods or products. This article reviews the definitions and measures that have been used to assess contraceptive efficacy, describes and illustrates some of the flaws that confound interpretation and comparison of studies, and presents a set of recommendations for future studies. A summary table providing comparative failure rates for all methods of contraception is included.

Confounding Factors, Epidemiologic↗

Age at first marriage and age at first birth.

This paper presents findings on patterns of age of 1st marriage and age of 1st birth for 41 countries participating in the World Fertility Survey program. The age distribution of 1st marriage and 1st birth is summarized with 3 statistics: the mean, the standard deviation, and the proportion ever experiencing the event. The particular method of estimation is based on a model that ensures that estimates for all cohorts are comparable, even though some women have completed their reproductive experience while others have not. The analysis provides insights into sources of error in the reporting of age at 1st birth. In addition, trends and cross-country patterns are documented and conclusions are drawn about the adequacy of these statistics for the description of patterns of age at 1st birth and age at 1st marriage.

Age Factors↗

Age and infertility.

Direct evidence on age patterns of infecundity and sterility cannot be obtained from contemporary populations because such large fractions of couples use contraception or have been sterilized. Instead, historical data are exploited to yield upper bounds applicable to contemporary populations on the proportions sterile at each age. Examination of recent changes in sexual behavior that may increase infecundity indicates that sexually transmitted infections, the prime candidate for hypothesized rises in infertility, are unlikely to have added to infecundity to any great extent. These results imply that a woman in a monogamous union faces only moderate increases in the probability of becoming sterile (or infecund) until her late thirties. Nevertheless, it appears that recent changes in reproductive behavior were guaranteed to result in the perception that infecundity is on the rise.

Adolescent↗

What are the determinants of delayed childbearing and permanent childlessness in the United States?

This paper presents estimates of delayed childbearing and permanent childlessness in the United States and the determinants of those phenomena. The estimates are derived by fitting the Coale-McNeil marriage model to survey data on age at first birth and by letting the parameters of the model depend on covariates. Substantively, the results provide evidence that the low first birth fertility rates experienced in the 1970s were due to both delayed childbearing and to increasing levels of permanent childlessness. The results also indicate that (a) delayed childbearing is less prevalent among black women than among nonblack women; (b) education is an important determinant of delayed childbearing whose influence on this phenomenon seems to be increasing across cohorts; (c) education is positively associated with heterogeneity among women in their age at first birth; (d) the dispersion of age at first birth is increasing across cohorts; (e) race has an insignificant effect on childlessness; and (f) education is positively associated with childlessness, with the effect of education increasing and reaching strikingly high levels for the most recent cohorts.

Adolescent↗

Evaluation of the Olsen technique for estimating the fertility response to child mortality.

In a previous issue of this journal, Olsen proposed a technique for quantifying the fertility response to child mortality. To estimate the extent of child replacement, one needs data only on the number of children ever born and the number of child deaths for each woman. The technique involves first running a regression of the number of births on the number of deaths and then correcting the regression coefficient in order to obtain a consistent estimate of replacement. Here we evaluate the performance of the technique by seeing how well it works on a simulated set of reproductive histories for which we known the true extent of replacement. In passing, we derive an extension of the technique to handle the situation in which replacement strategies are heterogeneous. We conclude that the technique performs very well, especially in those cases where the stochastic structure of the data can be diagnosed.

Adult↗

A hazards-model analysis of the covariates of infant and child mortality in Sri Lanka.

The purpose of this paper is twofold: (a) to provide a complete self-contained exposition of estimating life tables with covariates through the use of hazards models, and (b) to illustrate this technique with a substantive analysis of child mortality in Sri Lanka, thereby demonstrating that World Fertility Survey data are a valuable source for the study of child mortality. We show that life tables with covariates can be easily estimated with standard computer packages designed for analysis of contingency tables. The substantive analysis confirms and supplements an earlier study of infant and child mortality in Sri Lanka by Meegama. Those factors found to be strongly associated with mortality are mother's and father's education, time period of birth, urban/rural/estate residence, ethnicity, sex, birth order, age of the mother at the birth, and type of toilet facility.

Actuarial Analysis↗

Estimating the covariates of childhood mortality from retrospective reports of mothers.

In this paper we compare various models for estimating the covariates of childhood mortality from the type of data commonly available in developing countries. Specifically, we examine how much precision is lost as various pieces of information, such as dates of birth and death for each child, are discarded. The conclusion which we reach is that even incomplete mortality data of the type collected in household surveys or censuses can yield estimates which are very close to those based on the much richer wealth of data collected in detailed maternity histories. Two substantive conclusions of interest are that in the two countries (Sri Lanka and Korea) we examined, the education of the father has a significant and pronounced effect on childhood mortality even when the mother's education is controlled, and once other covariates are controlled, there is no difference between urban and rural childhood mortality.

Age Factors↗

A specification of marital fertility by parents' age, age at marriage and marital duration.

The positive association between wife's age at marriage and fertility experienced at the older reproductive ages, cited in recent natural fertility literature, is explored using Mormon birth cohorts from 1840 to 1879. When this relationship is specified by husband's age at marriage and marriage duration, the results indicate that older-aged husbands depress marital fertility only at higher marriage durations. The general decomposition of age-specific fertility utilizing both mother's and father's age is also considered. The results show that mother's aging is the most important factor, while father's aging has a moderately negative effect under a natural fertility regime.

Adolescent↗