Rosalie Dominik

Comparative Contraceptive Efficacy of The Female Condom and Other Barrier Methods

Because the research design for the clinical trial establishing the contraceptive efficacy of the female condom--a six-month life-table probability of failure of 15% (12% in the United States vs. 22% in Latin America)--did not include randomization with another method of contraception, no definite conclusion about its comparative efficacy is possible. Comparisons using other female barrier methods as historical controls, however, provide evidence that, among women in the United States, the contraceptive efficacy of the female condom during typical use is not significantly different from that of the diaphragm, the sponge or the cervical cap. The six-month probability of failure during perfect use of the female condom is 2.6% among U.S. women, similar to rates for the diaphragm and the cervical cap but significantly lower than that for the sponge. Meaningful comparisons with the male condom are not possible because of the lack of data from carefully controlled prospective clinical trials. Extrapolations from the results on contraceptive efficacy suggest that perfect use of the female condom may reduce the annual risk of acquiring the human immunodeficiency virus by more than 90% among women who have intercourse twice weekly with an infected male.

Understanding risk: a randomized controlled trial of communicating contraceptive effectiveness.

OBJECTIVE To determine which of three different approaches increased womens understanding of risk of pregnancy associated with different contraceptive methods. METHODS We randomly assigned 461 reproductive-age women to one of three tables presenting pregnancy risk (Food and Drug Administration table with numbers, World Health Organization table with numbers and categories, or table with categories). We evaluated participant knowledge before and after being shown the assigned table. RESULTS The most important reason for choosing a contraceptive was how well it works (53%), followed by ease of use (13%), and protection against sexually transmitted disease or human immunodeficiency virus (11%). Before looking at the tables, about half the participants knew that hormone shots are more effective than pills (48%) and that pills are more effective than condoms (57%). For these two key comparisons, the category table compared to the Food and Drug Administration table with numbers improved knowledge significantly more (37% versus 20% and 27% versus 14%; both P <.05). Compared with those assigned to the Food and Drug Administration table with numbers, significantly fewer participants assigned to the category table said the table was difficult to read (6% versus 19%; P <.01). Most participants in all three groups said their assigned table provided enough information to choose a contraceptive method. CONCLUSION The table with categories communicated relative contraceptive effectiveness better than the tables with numbers. However, without being presented with numbers, participants grossly overestimated the absolute risk of pregnancy using contraceptives. A combination of categories and a general range of risk for each category may provide the most accurate understanding of both relative and absolute pregnancy risk.

A COMPARATIVE STUDY OF THE NO SCALPEL AND STANDARD INCISION APPROACHES TO VASECTOMY IN 5 COUNTRIES

Purpose:: We compare the safety, ease of use and effectiveness of the no scalpel and standard incision approaches to vasectomy.Materials and Methods:: A multicenter, randomized, partially masked controlled trial was conducted at 8 sites in Brazil, Guatemala, Indonesia, Sri Lanka and Thailand. Semen samples were collected 10 weeks postoperatively and tested to ascertain sterility using verification of no living spermatozoa.Results:: The study included 1,429 men seeking vasectomy. The efficacy of the 2 approaches was virtually identical. In the no scalpel group operating time was significantly shorter, and complications and pain were less frequent than in the standard incision group. The no scalpel group resumed intercourse sooner, probably as a result of less pain following the procedure.Conclusions:: The no scalpel approach is an important advance in the surgical approach to vasectomy, and offers fewer side effects and greater comfort compared to the standard incision technique, without compromising efficacy.

Contraceptive effectiveness of a polyurethane condom and a latex condom: A randomized controlled trial

OBJECTIVE To compare the contraceptive effectivenesses of a polyurethane condom and a standard latex condom. Secondary outcomes of interest were safety, functionality, discontinuation, and acceptability. METHODS We randomized 901 couples to use either the polyurethane condom or a standard latex condom as their only form of contraception. We tested for pregnancy at enrollment and at every scheduled follow-up visit (weeks 4, 10, 16, 22, and 30). RESULTS The 6-month typical-use pregnancy probabilities were 9.0% (95% confidence interval [CI] 5.9, 12.2) for the polyurethane group and 5.4% (95% CI 2.9, 7.8) for the latex group; the hazard ratio was 1.7 (95% CI 1.1, 2.7), and we failed to reject the null hypothesis of our test of noninferiority. Females in the polyurethane group reported fewer genital irritations (hazard ratio 0.6; 95% CI 0.5, 0.8; P < .01), whereas males in both groups reported the same number of genital irritations (hazard ratio 1.0; 95% CI 0.7, 1.5; P = .94). Total clinical failures (breakage and slippage) were 8.4% for the polyurethane condom and 3.2% for the latex condom (difference 5.3%, 90% CI 2.8, 7.7). The risk of discontinuation did not differ between groups. Participants judged both condoms favorably in terms of the four primary acceptability outcomes (willingness to purchase, willingness to recommend, confidence in method, and general comfort). CONCLUSION The polyurethane condom was not shown to be as effective as the latex comparator condom for pregnancy prevention. However, the risk of pregnancy in the polyurethane group falls in the range of other barrier methods. For people with latex sensitivity or who find latex condoms unacceptable, this polyurethane condom represents one of several synthetic male condom alternatives currently available on the US market.

Lea's Shield®: A study of the safety and efficacy of a new vaginal barrier contraceptive used with and without spermicide

The purpose of this study was to evaluate the safety, efficacy and acceptability of Leas Shield, a new vaginal contraceptive barrier device, when used with either spermicidal or non-spermicidal lubricant. One-hundred-eighty-five (185) women enrolled at six centers. Half were randomized to use the device with spermicide and half with a non-spermicidal lubricant. To be eligible, volunteers had to be 18-40 years old (inclusive), in good health with regular menses, sexually active in an ongoing relationship and at risk for pregnancy, and willing to use Leas Shield as their sole means of contraception for six months. Participants were seen at admission, one week, one month, three months and six months. Gross cumulative life table rates were calculated for pregnancy and others reasons for discontinuation. Adverse experiences and responses to an acceptability questionnaire were evaluated. One-hundred-eighty-two (182) volunteers contributed data to the analysis of safety and 146 to that of contraceptive efficacy. The unadjusted six-month life table pregnancy rate was 8.7 per 100 women for spermicide users and 12.9 for non-spermicide users (p = 0.287). After controlling for age, center, and frequent prior use of barrier methods, the adjusted six-month life table pregnancy rate was 5.6 for spermicide users and 9.3 for non-spermicide users (p = 0.086), indicating that use of spermicide lowered pregnancy rates, although not significantly, during typical use. For purposes of comparison, it is important to note that this study differed from the cap/diaphragm and sponge/ diaphragm studies in that a high percentage (84%) of volunteers were parous. For reasons that are unclear, pregnancy rates among parous women using barrier contraceptives tend to be higher than among nulliparous women. Indeed, in this study there were no pregnancies among nulliparous users of Leas Shield. Standardization of parity of this study population on those of the cap/diaphragm and sponge/diaphragm studies suggests that unadjusted pregnancy rates for this device would have been considerably lower (2.2 and 2.9 per 100 users of spermicide and non-spermicide, respectively) had the study been done using the populations of earlier studies. Since no directly comparative study has been done, these figures provide a tentative estimate of the relative efficacy of Leas Shield compared with the sponge, cap, and diaphragm. There were no serious adverse experiences attributed to the use of Leas Shield. Acceptability was very good. Seventy-five percent (75%) of women responded to an end-of-study questionnaire; 87% of these reported that they would recommend Leas Shield to a friend. Leas Shield is a new vaginal contraceptive that does not require clinician fitting. Pregnancy rates in this study compare favorably with other studies of barrier contraceptive methods including the cervical cap, diaphragm, and sponge, even though this study was done with greater rigor and with a greater percentage of parous women than previous barrier studies. Leas Shield appears to be safe and very acceptable to study volunteers.

A comparative study of the safety and efficacy of femcap®, a new vaginal barrier contraceptive, and the ortho all-flex® diaphragm

The FemCap is a new silicone rubber barrier contraceptive shaped like a sailors hat, with a dome that covers the cervix, a rim that fits into the fornices, and a brim that conforms to the vaginal walls around the cervix. It was designed to result in fewer dislodgments and less pressure on the urethra than the cervical cap and diaphragm, respectively, and to require less clinician time for fitting. This was a phase II/III, multicenter, randomized, open-label, parallel group study of 841 women at risk for pregnancy. A subset of 42 women at one site underwent colposcopy. Women were randomized to use the FemCap or Ortho All-Flex contraceptive diaphragm, both with 2% nonoxynol-9 spermicide, for 28 weeks. The objectives were to compare the two devices with regard to their safety and acceptability and to determine whether the probability of pregnancy among FemCap users was no worse than that of the diaphragm (meaning not more than 6 percentage points higher). The 6-month Kaplan-Meier cumulative unadjusted typical use pregnancy probabilities were 13.5% among FemCap users and 7.9% among diaphragm users. The adjusted risk of pregnancy among FemCap users was 1.96 times that among diaphragm users, with an upper 95% confidence limit of 3.01. Clinical equivalence (noninferiority) of the FemCap compared with the diaphragm, as defined in this study, would mean that the true risk of pregnancy among FemCap users was no more than 1.73 times the pregnancy risk of diaphragm users. Because the observed upper 95% confidence limit (and even the point estimate) exceeded 1.73, the probability of pregnancy among FemCap users, compared with that among diaphragm users, did not meet the definition of clinical equivalence used in this study. The FemCap was believed to be safe and was associated with significantly fewer urinary tract infections. More women reported problems with the FemCap with regard to insertion, dislodgement, and especially removal, although their general assessments were positive. The two devices were comparable with regard to safety and acceptability, but a 6-point difference in the true 6-month pregnancy probabilities of the two devices could not be ruled out. Further studies are needed to determine whether design modifications can simplify insertion and removal.

Measuring contraceptive effectiveness: A conceptual framework

We present a conceptual model that outlines the four measures of how well a contraceptive method works: 1) efficacy, 2) effectiveness, 3) perfect-use pregnancy rate, and 4) typical-use pregnancy rate. Moreover, we illustrate how four variables influence these measures: 1) capacity to conceive, 2) frequency and timing of intercourse, 3) degree of compliance, and 4) inherent protection of the method. Because of inter-individual as well as intra-individual variability of the first three variables, generalizing results from a contraceptive clinical trial to other populations is problematic. There is a hierarchy of generalizability of the four outcome measures, with the typical-use pregnancy rate the least generalizable but the easiest to measure, and efficacy the most generalizable but the most difficult to measure. These four variables should be considered in the design and analysis of future contraceptive clinical trials. Finally, this article illustrates why the terms “pregnancy rate” and “failure rate” are not synonymous and why we recommend that the latter term not be used.

Two randomized controlled trials comparing the Tubal Ring and Filshie Clip for tubal sterilization

OBJECTIVE To compare the effectiveness and safety of the Filshie Clip and Tubal Ring systems when applied via minilaparotomy and laparoscopy. DESIGN Prospective, multicenter randomized controlled clinical trial, with postoperative evaluation by a physician who was masked to the operative technique. SETTING Healthy volunteers in a variety of hospital settings. PATIENT(S) 2746 women (915 in the minilaparotomy study and 1831 in the laparoscopy study) who had requested permanent surgical sterilization. INTERVENTION(S) Surgical tubal ligation, using either Filshie Clips or Tubal Rings. A physician other than the surgeon evaluated the patients after the operation and again at 1, 6, and 12 months after surgery. MAIN OUTCOME MEASURE(S) Pregnancy rates and safety-related events. RESULT(S) During the 12 months after surgery, two women who received the Filshie Clip and two women who received the Tubal Ring became pregnant, giving a 12-month life-table pregnancy probability of 1.7 per 1000 women in both groups. The Tubal Ring was more difficult to apply and had higher rates of tubal or mesosalpingeal injuries at surgery. The Filshie Clip group had three cases of spontaneous clip expulsion during the follow-up period. CONCLUSION(S) Both the Filshie Clip and Tubal Ring are effective and safe for use in tubal occlusion.

Management and treatment of diarrhea in Honduran children: Factors associated with mothers' health care behaviors

Data from the 1984 National Maternal-Child Health and Family Planning Survey in Honduras showed that one fifth (n = 711) of the children under five had experienced diarrhea on the day of the interview or the two days preceding the interview. The health care behaviors of the mothers of these children and the factors associated with these behaviors were the focus of this study. Only 22% of the mothers consulted medical personnel concerning the diarrhea episode; 74% treated their children with some type of medication while only 17% of the children received the recommended treatment, oral rehydration therapy. Most children were treated inappropriately, often receiving a combination of antibiotics, antidiarrheals and other drugs. Bivariate and multivariate analyses showed that the variables that most consistently predicted any and all three of the behaviors were the childs age and the severity of symptoms. Mothers of children two years and older were less likely to consult or use ORT than mothers of children 6-23 months of age. Mothers whose childrens diarrhea had lasted three or more days or who were vomiting were usually twice as likely to consult, give any type of treatment, or give ORT than mothers whose children had diarrhea for fewer days or who were not vomiting.

Contraceptive effectiveness of two spermicides: a randomized trial.

OBJECTIVE We conducted a multinational randomized trial to determine whether a spermicidal film containing 72 mg of nonoxynol-9 per film was at least as effective in preventing pregnancy as a foaming tablet containing 100 mg of nonoxynol-9 per tablet. METHODS Between September 1995 and July 1997, 765 women aged 18-35 years who had no evidence of subfecundity were randomly assigned to use one of the two spermicides as their only contraceptive method at every coital act for 28 weeks. Participants were asked to keep coital diaries throughout the study period. Pregnancy tests were performed on a scheduled basis. Each participant was followed for 28 weeks or until she stopped considering the spermicide as her primary method of contraception. RESULTS The Kaplan-Meier estimate of the 6-month probability of pregnancy during typical use of the spermicide was 28.0% in the tablet group and 24.9% in the film group (P = .78, one-tailed test). The study had nearly 75% power to have detected a difference of seven percentage points between groups. Results were almost identical when the analysis included only months when the participants reported use of the spermicide during every coital act. Reported levels of sexual activity and compliance with use of the spermicide were high in both groups. CONCLUSION The contraceptive effectiveness of these two spermicidal products appeared similar. Both products were associated with a fairly high risk of pregnancy in this young, highly sexually active population.