Comparison of self-reported female condom failure and biomarker-confirmed semen exposure

OBJECTIVE

To investigate whether rates of self-reported Woman's Condom (WC) clinical failure and semen exposure from a functionality study are comparable to results from a contraceptive efficacy substudy.

STUDY DESIGN

We structured our comparative analysis to assess whether functionality studies might credibly supplant contraceptive efficacy studies when evaluating new female condom products. Couples not at risk of pregnancy in the functionality (breakage/slippage/invagination/penile misdirection) study and women in the contraceptive efficacy study completed condom self-reports and collected precoital and postcoital vaginal samples for up to four uses of the WC. Both studies used nearly identical self-report questions and the same self-sampling procedures and laboratory for prostatic specific antigen (PSA), a well-studied semen biomarker. We compared condom failure and semen exposure proportions using generalized estimating equations methods accounting for within-couple correlation.

RESULTS

Ninety-five (95) efficacy substudy participants used 334 WC and 408 functionality participants used 1572 WC. Based on self-report, 19.2% WC (64 condoms) clinically failed in the efficacy substudy compared to 12.3% WC (194 condoms) in the functionality study (p=.03). Of the 207 WC efficacy uses with evaluable postcoital PSA levels, 14.5% (30 uses) resulted in semen exposure compared to 14.2% (184 uses) of the 1293 evaluable WC functionality study uses.

CONCLUSIONS

When evaluating the ability of an experimental condom to prevent semen exposure, the rate of clinical condom failure reported by participants risking pregnancy in an efficacy substudy was significantly higher than the rate reported by participants not risking pregnancy in a functionality study. The rate of semen exposure, assessed by an objective biomarker was nearly identical for the two studies.

IMPLICATIONS

Our results suggest that an objective marker of semen exposure in functionality studies could provide a reasonable alternative to contraceptive efficacy studies in evaluating risk of unintended pregnancy and inferring protection from sexually transmitted infection than condom failure rates based on self-report.

Couples' acceptability of the SILCS diaphragm for microbicide delivery

BACKGROUND

Disposable plastic applicators used in microbicide gel studies are expensive and have a negative environmental impact. The SILCS diaphragm is a barrier contraceptive that could offer a reusable delivery system.

STUDY DESIGN

Thirty-six couples in this randomized, cross-over study evaluated single- and double-sided gel delivery from a SILCS diaphragm compared with gel from an applicator. Couples used each gel scenario during two acts of intercourse and completed acceptability questionnaires after each.

RESULTS

All three scenarios received favorable ratings for ease of application, acceptability and perceived effectiveness. Both female and male participants tended to rate the gel applicator significantly more favorably than either SILCS gel delivery scenarios for all attributes except messiness/leakage and effectiveness. Additionally, about 60% of female participants and about half of male participants preferred the gel applicator to either of the gel delivery systems using SILCS. The preference for the SILCS scenario for pregnancy protection was statistically significant for both sexes. Male participants were also significantly more likely to prefer the SILCS single-sided delivery system to the gel applicator for protection from sexually transmitted infection.

CONCLUSIONS

In this study population, participants found the gel applicator to be more acceptable than either single- or double-sided gel delivery from a SILCS diaphragm. Further research of the SILCS as a microbicide delivery system should be implemented to assess its acceptability among study populations that reflect diverse potential user groups such as women and men from both low and high HIV prevalence settings including HIV-positive populations and with and without experience using female barrier methods.

Patterns of emergency contraception use by age and ethnicity from a randomized trial comparing advance provision and information only

PURPOSE

This study measures the impact of the advance provision of emergency contraception (EC) among family planning clients at 31 clinics in California.

METHODS

We randomized over 9000 clients to receive a packet containing either two 0.75-mg levonorgestrel pills (Plan B) or an identical packet containing EC information only. We conducted follow-up interviews on a subset of 1130 clients selected to optimize the age and ethnicity distribution. The interviews collected information on EC use, contraception, risk-taking behaviors and EC attitudes.

RESULTS

Clients who received EC in advance were significantly more likely to have used EC (19%) than women who received information only (12%) (p=.0009). There were no significant differences between the contraceptive and risk-taking behavior of the two treatment groups. Study respondents of all ages and ethnicities expressed positive attitudes about EC. Nevertheless, even with EC on-hand, many respondents who reported unprotected intercourse decided not to take EC.

CONCLUSION

More research should be done on the reasons women decide not to use EC even when readily available.

Male tolerance study of 1% C31G

BACKGROUND

C31G is being studied as a vaginal contraceptive and microbicide. This study was conducted to ensure that male partners of the women in future trials of C31G will not be subjected to an undue risk of penile irritation.

METHODS

This was a randomized, double-blinded, single-center Phase I study in circumcised and uncircumcised men to assess penile irritation, safety and acceptability of seven consecutive daily doses of 1.0% C31G compared with a marketed spermicide, Extra Strength Gynol II(R) (3% nonoxynol-9) (ES Gynol II). Each participant was instructed to apply the study product to his penis at bedtime, to wash it off 6-10 h later, and to record any symptoms on a diary card. At the follow-up visit, a genital examination was performed and participants were again asked about adverse events and to complete an acceptability questionnaire.

RESULTS

Of the 36 men enrolled, 12.5% of C31G users and 16.7% of Extra Strength Gynol II users reported product-related adverse events (AEs). All product-related AEs were considered mild by the investigator, except for one in the ES Gynol II group. Both products were acceptable.

CONCLUSION

The manner in which the products were used in this study is not the route by which men will be exposed to such products in actual use, and results should be considered in this light. Based on the observations in this study, C31G appears to be at least as safe and acceptable for male penile exposure as the marketed product ES Gynol II.

Effectiveness of the male latex condom: combined results for three popular condom brands used as controls in randomized clinical trials

BACKGROUND

Although public health programs invest heavily in the male latex condom, its efficacy in preventing pregnancy and sexually transmitted disease has been based primarily on in vitro and retrospective studies.

METHODS

We combine the results from two randomized, controlled contraceptive efficacy trials that used commercial latex condoms brands (Ramses Sensitol, LifeStyles, Trojan-Enz) in the control arms. Combining data from the two studies, we obtained longitudinal data covering 3526 menstrual cycles contributed by approximately 800 couples who used latex condoms exclusively for up to six menstrual cycles. Both trials also collected 3715 detailed breakage and slippage reports from the first five study condom uses. The second trial also tested 243 postcoital vaginal samples collected after the first study condom use for the presence of prostate-specific antigen (PSA) and spermatazoa.

RESULTS

The combined clinical breakage rate for the first five condom uses was 0.4% for the three latex brands and the combined clinical slippage rate was 1.1%. The combined six-cycle typical-use pregnancy rate for the latex condoms was 7.0% (95% confidence interval 5.0-9.0). The combined six-cycle consistent-use pregnancy rate was 1.0% (95% confidence interval 0.0-2.1). PSA was detected in only 1.2% of postcoital vaginal samples collected after the first use of an intact study condom. There were no differences in performance or efficacy among the three latex brands tested.

CONCLUSIONS

The male latex condoms rarely broke or slipped off during intercourse and provided high contraceptive efficacy, especially when used consistently. Risk of semen leakage from intact condoms was very low.

Safety and acceptability of penile application of 2 candidate topical microbicides: BufferGel and PRO 2000 Gel: 3 randomized trials in healthy low-risk men and HIV-positive men

OBJECTIVES

To assess safety and acceptability of penile application of BufferGel (ReProtect, Baltimore, MD) and PRO 2000 Gel (Indevus Pharmaceuticals, Lexington, MA)compared with placebo among low-risk sexually abstinent men and HIV-positive sexually abstinent men.

DESIGN

Seventy-two healthy low-risk men (36 uncircumcised) and 25 HIV-positive men (12 uncircumcised) were enrolled in 3 double-blind, single-center studies as follows: 36 low-risk men in a study of BufferGel and K-Y Jelly (McNeil-PPC, Skillman, NJ) placebo; 36 low-risk men in a study of PRO 2000 Gel and vehicle placebo; and 25 HIV-positive men in a crossover study of BufferGel, PRO 2000 Gel, and K-Y Jelly placebo.

METHODS

Participants applied product to the penis on 7 consecutive nights, kept study diaries, and were then interviewed and examined. Urine was tested for inflammation by leukocyte esterase.

RESULTS

No serious adverse events (AEs) or urethral inflammation was detected. During use of BufferGel, 3 low-risk men (13%) reported 6 AEs and 2 HIV-positive men (8%) reported 3 AEs. During use of PRO 2000 Gel, 4 low-risk men (17%) reported 6 AEs and 1 HIV-positive participant (4%) had 1 AE. AE rates during use of BufferGel and PRO 2000 Gel use were not significantly different from rates observed during placebo. One low-risk man (4%) would object to his partners using BufferGel and 3 (13%) to PRO 2000 Gel. Two HIV-positive men (8%) reported they would object to partners using either BufferGel or PRO 2000 Gel.

CONCLUSIONS

Daily application of BufferGel and PRO 2000 Gel directly to the penis consecutively for 7 days was generally safe and well tolerated among healthy low-risk men and HIV-positive men. These microbicides have acceptable safety profiles to proceed with planned phase 3 vaginal microbicide trials.

Evaluation of the efficacy of a nonlatex condom: results from a randomized, controlled clinical trial

CONTEXT

To reduce unintended pregnancy and HIV infection, it is critical to develop reliable male condoms that will attract consumers who reject conventional latex condoms.

METHODS

In a prospective clinical trial conducted in 1998-2000, 830 monogamous couples were randomized in equal numbers to use either a nonlatex condom or a commercial natural latex condom for six months as their only method of birth control. Couples completed detailed reports for the first five condom uses and recorded intercourse and condom use in coital diaries. Pregnancy rates associated with typical and consistent condom use were calculated using life-table analysis. Rates of clinical failure (condom breakage or slippage) were determined for the first five condom uses.

RESULTS

During the first five uses, the nonlatex condom had a higher frequency of breakage or slippage during intercourse or withdrawal (4.0%) than latex condoms (1.3%); the breakage rate for the nonlatex condom was about eight times that of latex condoms. The six-cycle typical-use pregnancy rate did not differ significantly between users of nonlatex (10.8%) and latex condoms (6.4%). The six-cycle consistent-use pregnancy rate was higher for nonlatex condom users than for latex condom users (4.9% vs. 1.0%).

CONCLUSIONS

The data present strong indirect support for public health messages that promote the use of latex condoms and, for individuals who cannot or are unwilling to use latex condoms, the use of nonlatex condoms for prevention of pregnancy and disease.

Use of prostate-specific antigen (PSA) to measure semen exposure resulting from male condom failures: implications for contraceptive efficacy and the prevention of sexually transmitted disease

Accurate measurement of semen exposure resulting from condom failures can refine public health messages and improve predictions of condom efficacy in preventing pregnancy and HIV transmission. Eight hundred and thirty couples enrolled in a condom efficacy study were asked to collect a baseline sample of ejaculate from the inside of the first study condom they used and to collect a postcoital vaginal sample whenever a study condom broke or slipped off during intercourse. All samples were quantitatively tested for prostate-specific antigen (PSA), a substance found only in human semen, using rocket immunoelectrophoresis, and inspected microscopically for presence of sperm. Sixty-eight baseline ejaculate samples collected from the inside of the first study condom by couples who subsequently experienced a condom failure averaged 13.4 microg PSA per swab and 79% of the samples averaged one or more sperm per high power field (hpf). Seventy-nine postcoital vaginal samples obtained after a condom break averaged 5.7 microg PSA per swab and only 38% averaged one or more sperm per hpf. The PSA results indicated a 50% reduction in semen exposure compared to baseline levels (p = 0.0001). Seventeen samples obtained after a condom slip-off averaged 2.5 microg PSA per swab and none of the samples averaged one or more sperm per hpf. The PSA results indicated an 80% reduction in semen exposure compared to baseline levels (p = 0.0001). Our results suggest that even condoms that fail reduce the risk of pregnancy and the transmission of sexually transmitted disease compared to unprotected intercourse. We also used PSA results to adjust a model designed to predict consistent-use pregnancy rates from condom breakage and slippage data.

Acceptability evaluation of a natural rubber latex, a polyurethane, and a new non-latex condom

After more than a century of reliance on latex condoms, male condoms fabricated from new materials are finally becoming commercially available to consumers. This study was an open label acceptability study that compared three lubricated condom products during vaginal intercourse: a natural rubber latex condom, a polyurethane condom, and a new non-latex (styrene ethylene butylene styrene, SEBS) condom. Fifty-four couples who were using condoms for birth control were enrolled in this three-way crossover study. Each couple tested three condoms of each type in a randomized sequence. Couples reported condom performance after each use and rated condom acceptability after use of three condoms of each type. At the completion of the study, participants selected their preferred condom type for overall acceptability, sensitivity, ease of use, appearance, and comfort. All three condom types had low clinical breakage and slippage rates (</= 3.3%) although the polyurethane condom did not perform as well in other measures of performance including unrolling, discomfort, stretching, bunching, and sliding along the penis during intercourse. None of the condom types were statistically preferred overall [males: natural rubber latex 37%, polyurethane 24%, new non-latex (SEBS) 37%, no preference 2%; females: natural rubber latex 33%, polyurethane 27%, new non-latex 37%, no preference 2%]. A statistically higher proportion of couples preferred both the natural rubber latex condom and the new non-latex condom above the polyurethane condom for ease of unrolling, and the natural rubber latex condom above the other condom types for perceived safety. Approximately two-thirds of both male and female participants preferred one of the two condoms made of synthetic materials suggesting that consumers will appreciate the availability of these products.

Evaluation of prostate-specific antigen as a quantifiable indicator of condom failure in clinical trials

The ability of condoms to retain all elements of semen during intercourse has been assessed by postcoital visual inspection and in vitro permeability studies. Yet, these observations may not be sufficiently precise or realistic. This pilot study evaluated prostate-specific antigen (PSA) as a semen marker of inapparent failure of the condom barrier under conditions of actual use. Twelve couples collected samples from the vagina and surfaces of the condom using sterile cotton swabs. We obtained precoital and postcoital samples for 24 acts of unprotected intercourse, 54 acts of intercourse using intact condoms, and 40 acts of intercourse using condoms that had been deliberately punctured. We used electrophoresis to determine the amount of PSA present in the samples. PSA was detected in 100% (24/24) of vaginal samples collected immediately after unprotected intercourse and in none of the vaginal samples collected more than 24 h after intercourse (0/90). PSA was also present in 98% (83/85) of the samples collected from the inside of the condom that had failed during intercourse. Excluding uses where the condom failed during intercourse, PSA was detected in 2% (1/47) of the postcoital vaginal samples collected after use of intact condoms and in 41% (14/34) of the samples collected after use of condoms with known 1-mm punctures. We conclude that PSA shows great promise as a semen biomarker in clinical trials of barrier methods. We recommend that future studies further investigate the ability of this biomarker to identify condom failures and quantify the extent of semen exposure associated with various types of condom failures.

Evaluation of the efficacy of a polyurethane condom: results from a randomized, controlled clinical trial

CONTEXT

Condoms made of latex are not comfortable or appropriate for all consumers. Polyurethane condoms may provide a needed alternative.

METHODS

In a double-masked study, 805 monogamous couples were randomized to use either the polyurethane condom or the latex condom for six months. Couples recorded the frequency of intercourse, of condom use and of breakage and slippage throughout the trial in coital diaries and in detailed reports on the first five uses. Breakage and slippage rates were determined, and typical-use and consistent-use pregnancy rates were calculated using life-table analysis, adjusted for use of emergency contraception.

RESULTS

The six-month pregnancy rate during typical use (adjusted for use of emergency contraception) was 4.8% for the polyurethane condom and 6.3% for the latex condom. Similarly adjusted pregnancy rates during consistent use over six completed menstrual cycles--2.4% for the polyurethane condom and 1.1% for the latex condom--did not differ significantly. Clinical failure rates (including breakage and slippage occurring during either intercourse or withdrawal) were 8.5% for the polyurethane condom and 1.6% for the latex condom. In general, male participants were more satisfied with the latex condom, and users of latex were significantly less likely to drop out of the study for condom-related reasons than were users of polyurethane.

CONCLUSIONS

Although polyurethane and latex condoms provide equivalent levels of contraceptive protection, the polyurethane condom's higher frequency of breakage and slippage suggests that this condom may confer less protection from sexually transmitted infections than does the latex condom.

Breakage and acceptability of a polyurethane condom: a randomized, controlled study

CONTEXT

Although the first commercial polyurethane condom was approved for use several years ago, no U.S. clinical trial has compared its performance to that of the latex condom.

METHODS

In a masked crossover study, 360 couples were randomized to use three polyurethane condoms and three latex condoms. After each use, couples recorded condom breaks, condom slips and other aspects of performance. At completion of the study, couples compared the sensitivity, ease of use, fit and lubrication of the two types of condoms.

RESULTS

The clinical breakage rate of the polyurethane condom was 7.2%, compared with 1.1% for the latex condom (relative risk of 6.6, 95% confidence interval of 3.5-12.3). The complete slippage rate (combining incidents during intercourse and withdrawal) of the polyurethane condom was 3.6%, compared with 0.6% for the latex condom (relative risk of 6.0, 95% confidence interval of 2.6-14.2). Most male users preferred the sensitivity provided by the polyurethane condom to that of the latex condom.

CONCLUSIONS

The clinical breakage rate of the polyurethane condom is significantly higher than that of the latex condom. However, nearly half of the users preferred the polyurethane condom, which provides an option for couples who have rejected conventional condoms or who cannot use latex products.

Response of individuals with reactive airway disease to sulfates and other atmospheric pollutants

Severity of daytime and nighttime symptoms and medication requirements of 34 asthmatic volunteers were correlated to pollutant-pollen levels and to meteorologic characteristics continuously recorded over an eight-month period. Results of this longitudinal study suggest that as many as 9% of asthmatics may be sensitive to levels of sulfate in the ambient air and that reduction of sulfate levels to below 10 microgram/ml3 would significantly reduce tha frequency and severity of symptoms and needs for medication in these individuals.