Use-effectiveness of oral and intrauterine contraception

The IUD and the pill: extended use-effectiveness

Lewit S et al., 1971 · Fam Plann Perspect

The extended use-effectiveness of IUD and oral pills as measured by 1) their theoretical effectiveness 2) consistency of use and 3) continuation of use in preventing unwanted pregnancies was studied for 2900 women who had chosen either method as their first contraceptive in family planning clinics in Atlanta Georgia and in Brooklyn and Buffalo New York for a 12-18 month period. The greater persistence among IUD users to continue the method or use another method and the less likelihood there was of these women to have an unplanned pregnancy (the difference between IUD users and pill users increasing with months of exposure) suggest the necessity of greater support from the clinics to help women using pills prevent unwanted pregnancies. IUD users were generally older than pill acceptors and among IUD contraceptors the greater tendency to continue using the IUD and contraception may indicate that older women use contraception to terminate rather than to space childbirth.

Statistical evaluation of contraceptive methods: Use-effectiveness and extended use-effectiveness

Lewit S et al., 1968 · Demography

The recent advent of national family planning programs and the expansion of local programs have created an acute need for accurate statistical evaluation of contraceptive methods. Effectiveness in terms of pregnancy rates and continuation or discontinuation of use of the contraceptive method or methods under study have emerged as the major criteria in such evaluations.

The clinical effectiveness of contraceptive methods

Tietze C, 1959 · Am J Obstet Gynecol

Physiologic effectiveness is the measure of protection against unwanted pregnancy afforded by a specific contraceptive method under ideal conditions ie, used consistently and according to instructions-without omissions, or errors of technique. Such ideal conditions are rarely present. Even when they are, it is not practicable to observe and verify them. Physiologic effectiveness, although not accessible to direct measurement, is by definition higher than the observed clinical effectiveness of the same method in the hands of the most …

Time required for conception in 1727 planned pregnancies

Guttmacher AF et al., 1950 · Fertil Steril

Contraceptive Failure in the United States: Estimates from the 2006-2010 National Survey of Family Growth

Sundaram A et al., 2017 · Perspect Sex Reprod Health · Free full text on PubMed Central

Contraceptive failure rates measure a woman's probability of becoming pregnant while using a contraceptive. Information about these rates enables couples to make informed contraceptive choices. Failure rates were last estimated for 2002, and social and economic changes that have occurred since then necessitate a reestimation. To estimate failure rates for the most commonly used reversible methods in the United States, data from the 2006-2010 National Survey of Family Growth were used; some 15,728 contraceptive use intervals, contributed by 6,683 women, were analyzed. Data from the Guttmacher Institute's 2008 Abortion Patient Survey were used to adjust for abortion underreporting. Kaplan-Meier methods were used to estimate the associated single-decrement probability of failure by duration of use. Failure rates were compared with those from 1995 and 2002. Long-acting reversible contraceptives (the IUD and the implant) had the lowest failure rates of all methods (1%), while condoms and withdrawal carried the highest probabilities of failure (13% and 20%, respectively). However, the failure rate for the condom had declined significantly since 1995 (from 18%), as had the failure rate for all hormonal methods combined (from 8% to 6%). The failure rate for all reversible methods combined declined from 12% in 2002 to 10% in 2006-2010. These broad-based declines in failure rates reverse a long-term pattern of minimal change. Future research should explore what lies behind these trends, as well as possibilities for further improvements.

Use of contraception and use of family planning services in the United States: 1982-2002

Mosher WD et al., 2005 · Adv Data

This report presents national estimates of contraceptive use and method choice based on the 1982, 1995, and 2002 National Surveys of Family Growth (NSFG). It also presents data on where women obtained family planning and medical services, and some of the services that they received. Data were collected through in-person interviews with 12,571 men and women 15-44 years of age in the civilian noninstitutional population of the United States in 2002. This report is based on the sample of 7,643 women interviewed in 2002. The response rate for women in the study was about 80 percent. The leading method of contraception in the United States in 2002 was the oral contraceptive pill, used by 11.6 million women; the second leading method was female sterilization, used by 10.3 million women. The condom was the third-leading method, used by about 9 million women and their partners. The condom is the leading method at first intercourse; the pill is the leading method among women under 30; and female sterilization is the leading method among women 35 and older. More than 98 percent of women 15-44 years of age who have ever had sexual intercourse with a male (referred to as "sexually experienced women") have used at least one contraceptive method. Over the 20 years from 1982 to 2002, the percent who had ever had a partner who used the male condom increased from 52 to 90 percent. The proportion who had ever had a partner who used withdrawal increased from 25 percent in 1982 to 56 percent in 2002. Another important measure of contraceptive use is use at the first premarital intercourse: before 1980, only 43 percent of women (or their partner) used a method of birth control at their first premarital intercourse. By 1999-2002, the proportion using a method at first premarital intercourse had risen to 79 percent.

Behavioral methods of family planning: A comparative study of efficacy and safety

Dumitru AM et al., 2016 · Issues Law Med

Background and PurposePublished reports indicate that over 100 million women worldwide use the birth control pill (Oral Contraceptives, or OCPs).1,2 However, in a national study conducted by the Battelle Centers for Public Health Research and Evaluation, rates of discontinuation of some birth control methods were as high as 90%, and had averages between 40-61% (depending on marital status) for women who were followed over a two-year period.3 This suggests that women are searching for new methods, perhaps with fewer side effects or better effectiveness rates. Studies show up to 60% of women would be interested in using Fertility Awareness Based Methods (FABMs) if given information.4 Both FABMs and OCPs entail behavior modification on a daily basis, so the efficacy and side effects of FABMs and OCPs were chosen for comparison during this study.Most commonly reported unintended pregnancy rates for FABMs and OCPs are based on low quality retrospective surveys. A popularly cited review from J. R. Trussell and colleagues reports typical use failure rates of 24% for FABMs and 9% for OCPs.5 These numbers are based on estimates of the probability of pregnancy drawn from the 1995 and 2002 National Surveys of Family Growth.5'6 There are at least three major problems with these surveys. One is that these are lower quality retrospective surveys based primarily on patient recall, with the data collected via a series of phone surveys. Another major problem is that 86% of the purported FABM users surveyed identified the calendar method-a much older and less effective method-as their primary form of contraception. Then, the rates for all types of FABMs were pooled together, including some methods which are not even classified as FABMs by trained providers. This lumping together of all FABMs including rhythm masks important differences in effectiveness among the variety of modern methods; a fact acknowledged by Trussell, the author of this estimate.7'8'9 The third major issue with this review is that the rates of effectiveness were adjusted to account for the researchers' assumption of underreporting of abortion. As a result of the issues with these popularly cited statistics, we sought to design objective criteria with which to evaluate the primary literature available for FABMs and OCPs, in order to understand both the quality of the studies available as well as the true effectiveness rates. In total, three major search engines (Medline, PubMed, and EMBASE) were used with keyword searches to identify relevant articles. For FABMs, 30 articles from 1980 on were included in the study.6 For OCPs, 47 articles from 2000 on were included in the study. (The year 2000 was chosen in part because studies from earlier decades had used higher dose hormone formulations which were proven to be unsafe for women, and the trend in later years has been towards seeking lower dose hormonal formulations to provide the same efficacy with fewer side effects1). Strength of Recommendation Taxonomy (SORT) criteria10 were established first for the FABM review6 and then adapted for the OCP review (Adapted SORT). The adaptation was based on fundamental differences between FABMs and OCPs such as lack of a learning phase for OCPs. The purpose of the SORT and Adapted SORT criteria was to provide a framework to determine the level of evidence for individual studies.Two independent reviewers scored each of the identified articles for the FABMs and the OCPs reviewed. Major discrepancies in scores were resolved by sending the articles in question to a third reviewer for a tie-break score. For the FABMs reviewed, there were 56 maximum possible points with the SORT criteria. The scores ranged from 31-55 points, and 10 of the 30 articles (30%) were found to earn a SORT Level 1 status (qualified by earning a positive score in all of the critical criteria).6For the OCPs reviewed, there were 42 maximum possible points with the Adapted SORT criteria. …

A long-term follow-up study of women using different methods of contraception--an interim report

Vessey M et al., 1976 · J Biosoc Sci

Summary In 1968, a prospective study was started in collaboration with the Family Planning Association to try to provide a balanced view of the beneficial and harmful effects of different methods of contraception. This investigation is now in progress at seventeen clinics and over 17,000 women are under observation. At the time of recruitment, all these women were married white British subjects, aged 25–39 years, who voluntarily agreed to participate. Fifty-six per cent were using oral contraceptives, 25% were using a diaphragm and 19% were using an intrauterine device (IUD). During follow-up each woman is questioned at return visits to the clinic and a record of pregnancies and their outcome, hospital referrals (inpatient or outpatient), changes in contraceptive methods and the results of cervical smears, is accumulated. Women who default are sent a postal questionnaire and, if this is not returned, are telephoned or visited in their homes to collect the necessary information. So far, data obtained during 56,000 woman-years of observation are available for analysis. Follow-up has been maintained with an annual lapse rate of about 0.3%due to withdrawal of co-operation or loss of contact; adherence to the method of contraception in use at recruitment has been reasonably good, and the reporting of pregnancies and hospital admissions appears to have been both reliable and unbiased. The present data include only 24 deaths, so the mortality associated with different contraceptive methods cannot yet be estimated. With regard to morbidity, however, our preliminary results closely resemble those obtained in the prospective study carried out by the Royal College of General Practitioners (1974) and in the principal retrospective studies carried out in Britain and the United States. Women who used oral contraceptives at the start of the study experienced a deficiency of hospital referrals for cancer, benign lesions of the breast, menstrual disorders other than amenorrhoea, duodenal ulcer, and retention cysts of the ovary; they showed an excess of referrals for cerebrovascular disease, cervical erosion, skin disorders, self-poisoning, migraine, venous thrombosis and embolism, hayfever, gallbladder disease, amenorrhoea, and sterility. Women who used a diaphragm showed a deficiency of hospital referrals for carcinoma-in-situ and dysplastic lesions of the cervix uteri and accidental injury; and an excess of referrals for haemorrhoids and cystitis. Women who used an IUD experienced an excess of hospital referrals for anaemia, varicose veins and salpingitis. About half of these differences (12 out of 23) were predicted from other studies while some suggestive evidence already existed for a further five. Of the remaining six, some probably reflect the influence of selective factors or chance. Multiple pregnancies, stillbirths, malformations, the sex ratio and birthweight showed no consistent relationship to method of contraception. The outcome of unplanned pregnancies occurring in women using an IUD, however, was remarkably unfavourable both in terms of ectopic gestation and miscarriage. Clear evidence was found of impairment of fertility after discontinuation of oral contraceptives. Whether this is likely to lead to permanent sterility in some women is uncertain. The study has provided data on the efficacy of a wide variety of contraceptive methods. In general the failure rates are in keeping with those obtained in other large-scale studies, save that those for the diaphragm and the sheath are much lower than those usually quoted. The available evidence does not yet allow a final balance to be struck between the benefits and risks associated with the new methods of contraception that have become widely used during the last two decades. It seems clear, however, that there are no material risks associated with the use of the diaphragm apart from the risk of pregnancy and that there may be some unintended benefits.