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Results for “Contraceptive Usage--statistics”

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16 recordsLinked to original sources

Breast cancer detection in relation to oral contraception.

Analyses of tumor size and breast cancer stage were used to determine whether biased detection of breast cancer could have materially influenced estimates of risk associated with use of oral contraceptives. In a population-based case-control study conducted from 1980-1982, surveillance for breast cancer by breast exams, but not mammography, was found to be strongly linked to use of oral contraceptives. Tumors were slightly smaller and less likely to be late-stage (TNM stage III or IV) in patients who had used oral contraceptives. The net effect of any diagnostic bias on advancing the date of cancer diagnosis, whether from breast exams or other sources, was estimated to be less than 8 weeks. This corresponds to spuriously increasing the risk of early-occurring breast cancer in oral contraceptive users by at most 2.4% (relative risk = 1.024).

Adult

A comparative study of 35 mcg and 50 mcg combined oral contraceptives: results from a multicenter clinical trial.

A comparative multicenter clinical trial of two combined oral contraceptives (OCs) differing only in the estrogen content (35 mcg ethinyl estradiol versus 50 mcg mestranol) was conducted at five clinics located in Yugoslavia, Egypt, Sri Lanka, Costa Rica and Mexico. The trial was designed to determine the differences between Norinyl 1+35 (Syntex) and Norinyl 1+50 (Syntex) in rates and reasons of discontinuation, and frequency of selected side effects which might contribute to method discontinuation. This report includes analysis of 1698 women, all of whom were interval patients (at least 42 days but within 26 weeks postpartum), randomly allocated to one of the above OCs between October 1982 and January 1984. Follow-up visits were scheduled at 1, 4, 8 and 12 months after admission. Significantly more women in the Norinyl 1+35 group (p less than .001) reported intermenstrual bleeding (primarily staining and spotting), as well as an increase in the occurrence of intermenstrual bleeding compared to women in the Norinyl 1+50 group. There were no significant differences between the groups for side effects with the exception of more women in the Norinyl 1+50 group (p less than .05) reporting breast discomfort. The lost to follow-up rate at 12 months was 19.3% for both the Norinyl 1+35 and the Norinyl 1+50 groups. The total discontinuation rate (including women lost to follow-up) at 12 months was 43.5% for the Norinyl 1+35 group and 41.0% for the Norinyl 1+50 group. There were no significant differences between the two groups for gross cumulative life table discontinuation rates (p greater than .05). There were six accidental pregnancies attributed to user failure reported during the study period; four in the Norinyl 1+35 group and two in the Norinyl 1+50 group.

Adult

Gender differences in knowledge, intentions, and behaviors concerning pregnancy and sexually transmitted disease prevention among adolescents.

Gender differences in knowledge, intentions, and behaviors regarding preventing pregnancies and sexually transmitted diseases were studied. Data for the study were collected from 1,033 students in 13 California high schools. Females in this sample were more likely than males to have discussed sexuality topics with parents, to have engaged in sexual intercourse more frequently, to have experienced a pregnancy scare, to have used oral contraceptives during their last sexual encounter, to perceive that a larger proportion of their peers were engaging in sex and using birth control, to obtain birth control from health facilities, and to report intentions to abstain or use protection in hypothetical situations placing them at risk for unprotected sex. In contrast, males reported that they were more likely to have always used birth control, to have used birth control during their first sexual encounter, and to have used a condom during their last sexual encounter. Furthermore, males were more likely to obtain birth control from a store or a friend. Finally, males knew more about using condoms correctly and their role in preventing sexually transmitted diseases. The efficacy of interventions designed to reduce unintended pregnancy and sexually transmitted diseases among adolescents may be increased by addressing these gender differences. Understanding gender differences may also facilitate an increased role for males in the overall prevention scheme. Further research is clearly needed to increase knowledge about these gender differences.

Adolescent

Fertility rates in 238 HIV-1-seropositive women in Zaire followed for 3 years post-partum.

Birth-control use and fertility rates were prospectively determined in 238 HIV-1-seropositive and 315 HIV-1-seronegative women in Kinshasa, Zaire, during the 36-month period following the delivery of their last live-born child. No women delivered children during the first follow-up year. Birth-control utilization rates (percentage use during total observation time) and fertility rates (annual number of live births per 1000 women of child-bearing age) in the second year of follow-up were 19% (107.4 per 1000) for HIV-1-seropositive women and 16% (144.7 per 1000) for HIV-1-seronegative women. In the third year of follow-up these rates were 26 (271.0 per 1000) and 16% (38.6 per 1000) for HIV-1-seropositive and HIV-1-seronegative women, respectively (P less than 0.05 for the difference in birth-control utilization and fertility rates between seropositive and seronegative women in the third year of follow-up). Seven (2.9%) of the 238 HIV-1-seropositive women initially included in the study brought their sex partners in for HIV-1 testing; three (43%) of these men were found to be HIV-1-seropositive. New HIV-1 infection did not have a dramatic effect on the fertility of seropositive women. The nearly uniform unwillingness of HIV-1-seropositive women to inform husbands or sexual partners of their HIV-1 serostatus accounted in large part for the disappointingly high fertility rates in seropositive women who had been provided with a comprehensive program of HIV counseling and birth control. Counseling services for seropositive women of child-bearing age which do not also include these women's sexual partners are unlikely to have an important impact on their high fertility rates.

AIDS-Related Complex

Modelling digit preference in fecundability studies.

Retrospective studies of fecundability, in which women are asked how many cycles they required to become pregnant, are often affected by problems of digit preference. A probability model for such digit preference is proposed in which misreporting favours 6 or 12 (and possibly also 3) cycles. It is assumed that in the absence of misreporting the number of cycles follows a beta-geometric distribution. The model is applied to two data sets, with clear-cut results: The inclusion of additional parameters to model the misreporting can lead to substantial improvements in fit, but causes little change to the estimated parameters of the underlying beta-geometric distribution. In some cases misreporting parameters may be regarded as nuisance parameters, while in others they may be of interest. We have found estimates of these parameters to vary between different categories of women in an interpretable manner. The models may also be used to estimate the percentage of couples in any study that misreport their conception waiting time.

Biometry