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Biomedical subjects

I Sivin

Publications and source records attributed to I Sivin.

13 recordsLinked to original sources
PubMed1979

A randomized double blind study of two oral contraceptives.

To study the question of whether one brand of oral contraceptives may be as acceptable as another for use of publicly-assisted family planning programs, a double blind study of two well-known brands, Ovral and Norinyl, was undertaken in Costa Rica and Trinidad. The pills were randomly assigned to 1,200 women. Common side effects - nausea, dizziness, vomiting, headaches - were associated with both Norinyl and Ovral. Differences in event rates for these conditions were much more marked by country than by the pill used. Ovral was associated with increases in skin problems, notably chloasma, in Cost Rica. A higher percentage of women using Norinyl reported intermenstrual bleeding and spotting in both countries. In Costa Rica continuation rates for Norinyl were adversely affected by this. With these exceptions there appear to be no important differences between the brands that would affect their use in family planning programs.

Adolescent↗
PubMed1979

Copper T IUD use and ectopic pregnancy rates in the United States.

Over a four-year exposure period, the rate of ectopic pregnancy for women using a Copper T IUD was less than 1 per 1000 years of use. The cumulative 4-year probability of having an ectopic pregnancy while using the Copper T was 4 per 1000 women. These results are based on a study of 35,496 women with 38,064 years of use. Data on ectopic pregnancies in the United States provide a basis with which IUD experience may be compared. The National Hospital Discharge Survey shows a doubling in the number of ectopic pregnancies and in the incidence rates between 1965 and 1976. The relative risk of ectopic pregnancy among IUD users as compared with sexually active women not using the pill or sterilization may have been above 1 in 1965. In 1976, the relative risk is estimated to have been below 1. Compared with all woman-years of exposure, including women using contraceptive sterilization and the pill, the relative risk of extopic pregnancy to IUD users in 1976 was about 1. The IUD could not have been a major factor contributing to the recent doubling in the rate of ectopic pregnancy in the U.S.

Adult↗
PubMed1978

Long acting contraceptive implants. An analysis of menstrual bleeding patterns.

The menstrual patterns of women using subdermal implants of levonorgestrel and norgestrienone included in a double-blind clinical trial was evaluated by the method developed by the International Committee on Contraception Research. Women using Copper T200 randomly selected in the same clinics were used as controls. Both implant regimens were associated with a high frequency of reduced bleeding and norgestrel patients had also a high proportion of increased and irregular bleeding. Termination of use was associated to increased bleeding but not so much to reduced bleeding.

Adolescent↗
PubMed1977

Copper T 22oC.

Explore the source record for details and available documents.

Female↗
PubMed1977

Life-table analysis of IUDs: problems and recommendations.

Two major prospective studies of copper-bearing IUDs showed substantial changes in termination rates when calculated at different dates. One of the studies employed the Tietze life-table method and showed progressive increases in termination rates with the passage of time. The other study used the Potter life-table method and showed sharply decreased termination rates at later assessments. In investigating the reasons for these changes, it was noted that the data collected for periodic analyses during the studies violated the assumptions underlying the life-table technique. It was discovered that as a result of these violations the Potter and the Tietze life-table calculations based on the same set of data produced markedly different estimates of IUD termination rates during the course of a study. Underlying these differences, and the reason for the apparent changes in termination rates, was a large set of incomplete observations. Neither of the two life-table methods was able to deal adequately with the biases arising from these incomplete observations. The "anniversary method," devised to overcome the perceived problems of the Potter and Tietze methods, also proved inadequate to deal with the incomplete observations. Only vigorous and active follow-up, together with ample time to complete data collection, editing, coding, and key punching, is likely to reduce the proportion of women with incomplete observations and is likely to minimize the biases attendant upon incomplete or partial observations of acceptors in prospective clinical studies of IUDs.

Evaluation Studies as Topic↗
PubMed1976

A comparison of the copper T-200 and the Lippes Loop in four countries.

A comparative field trial of the Copper TCu-200 and the Lippes loop was conducted in Colombia, Iran, Korea, and Thailand from 1971 to 1973. The study, involving 7,400 women, provided two-year first segment continuation and termination rates. In three countries, TCu-200 expulsion rates were significantly below Lippes loop expulsion rates. For women with three or fewer living children, TCu-200 expulsion rates were markedly below Lippes loop rates in all four countries. The comparative advantage accruing to the TCu-200 in this characteristic did not extend to the two-year continuation rates.

Adult↗
PubMed1975

The international postpartum family planning program: eight years of experience.

The International Postpartum Program was begun in 1966 in order to demonstrate the feasibility of providing efficient and effective family planning services in the context of the obstetrical care provided by hospitals. The project included 138 institutions in 21 countries. Over an eight-year period, 1.14 million women were recruited, representing 33 acceptors per 100 obstetrical/abortion patients in these hospitals. Relying primarily on modern methods of contraception, the pill, the IUD, and sterilization, the program provided about 124 years of contraceptive protection for each 100 obstetrical/abortion patients, or somewhat more than four years' protection per acceptor. Predischarge insertion of IUDs was found to be safe and effective. In all countries, the program acceptors experienced important changes in fertility over and above the effects of aging. The demonstration showed that basing a program on activities in the obstetrical wards permits a rapid buildup of services, without great cost for construction. Whether using specially trained additional staff to provide family planning education and information or relying on the existing staff, hospitals were able to recruit a substantial proportion of women on the maternity wards as acceptors. Cost per acceptor averaged about US$5.00 during the eight-year period--considerably below the cost per acceptor in the majority of national programs. Such economy arose because acceptance ratios for the International Postpartum Program were higher than ratios for national programs where the target population is more dispersed, and because only direct costs for the services needed to be considered. The idea of uniting family planning information and services with the maternity services of hospitals has been seized upon and replicated outside the International Postpartum Program. The governments of India, Pakistan, Indonesia, Colombia, Thailand, and the Philippines, among others, now operate such systems. Postpartum programs still do not reach substantial segments of the urban population in the developing world, but the expansion of such services is continuing. Also, adaptations of maternity-centered family planning programs are now being tested in rural areas in the world, where most children are born.

Abortion, Induced↗
PubMedDate not supplied

Measuring contraceptive efficacy and side effects.

To assess effectiveness of contraceptives, one reports all pregnancies during use. Multiple and single decrement life-table pregnancy rates computed from these reports constitute the fundamental measures of effectiveness in clinical trials. Minimally biased evaluation of a new method requires a randomized, double-blind (or its nearest semblance), multicentered study of sexually active women. New contraceptives are studied in special, volunteer populations. Evaluation of marketed contraceptives implies broader-gauged representation, larger numbers and longer time frames. Prospective studies, like clinical trials, should include several methods, and may use subsamples for case-control analysis of risk. Well-designed and executed multicentered, prospective studies, nevertheless, may represent specially selected populations. Risk-benefit analyses based on findings from selected populations require careful scrutiny. Although the most persuasive estimates of effectiveness derive from national, representative samples, moderately large samples in the USA have not been able to distinguish among products within a class. Formidable problems of recall are present in household surveys. In the United Kingdom, Europe and North America, analysis of risks and benefits may be enriched by better utilization of the data collection and record linkage resources of national health statistics systems.

Actuarial Analysis↗