Issues in the design, analysis and interpretation of condom functionality studies

Performance of Male Condoms When Used With and Without a Silicone Placebo Vaginal Ring-A Randomized, Crossover Trial

BACKGROUND

The dapivirine vaginal ring reduced the risk of HIV infection by approximately 30% in Phase III trials. To ensure higher levels of protection against HIV and sexually transmitted infections, women should be counseled to use condoms when using the vaginal ring. This article evaluates the compatibility of male condoms with a placebo vaginal ring.

METHODS

This was a 2-period crossover, randomized, noninferiority trial. Couples in 2 sites in the United States were randomized to male condom use, with and without a placebo silicone vaginal ring, and asked to use 4 male condoms in each period. The primary noninferiority end points were total clinical failure and their component failure events (clinical breakage or slippage). Frequencies and percentages were calculated for each failure mode and differences in performance of the 2 periods using the male condom without the ring as reference. Noninferiority was defined using a 3% margin at the 5% significance level. Safety and acceptability were also assessed.

RESULTS

Seventy couples were enrolled, and 68 completed the trial with a total of 275 male condoms used in each period. Total condom clinical failure rates were 2.2% and 4.0% in the presence and absence of the vaginal ring, respectively, with a difference of -1.9% (95% confidence interval: -5.3% to 1.5%), thereby demonstrating noninferiority when used with the ring. There was no difference in safety between the 2 periods.

DISCUSSION

Concurrent use of the placebo silicone vaginal ring had no significant effect on male condom functionality or safety outcomes.

Functional performance study of an adapted design of the woman's condom: a crossover, noninferiority, randomized clinical trial

Objectives: We aimed to assess the functional performance and safety of a modified Woman's Condom (WC2) against the existing FC2 female condom. Study design: This randomized clinical trial enrolled 287 women in one South African site. The primary outcome of the study was the rate of female condom failure. Participants were asked to use five of each female condom type and to collect information on use in a condom log at home and were interviewed after use of each FC type. Results: Noninferiority was demonstrated for the WC2 with respect to the reference condom FC2 for all condom functions. The WC2 was found to be superior to the FC2 reference condom for clinical failure (p = .000), total female condom failure (p = .001), misdirection (p = .000) and slippage (p = .004). Conclusion: The WC2 female condom performs as well as the FC2 female condom and offers good stability during use. Implications: Results from this study will inform further refinement of this female condom design, resulting in a new and potentially less expensive Woman's Condom.

Double-Blind, Single-Center, Randomized Three-Way Crossover Trial of Fitted, Thin, and Standard Condoms for Vaginal and Anal Sex: C-PLEASURE Study Protocol and Baseline Data

Background

Male condoms are underused despite their ability to prevent transmission of HIV and other sexually transmitted infections. The perception of decreased sexual pleasure and poor condom fit are major contributors to condom nonuse.

Objective

The purpose of this study was to compare event-level performance and pleasure using fitted, thin, and standard condoms among men who have sex with men (MSM) and men who have sex with women (MSW). We also sought to assess condom type preference. We present the study design and enrollment data from the trial.

Methods

This study recruited sexually active men aged 18 to 54 years in Atlanta, Georgia, United States. We enrolled 252 MSM and 252 MSW in a double-blind, 3-way randomized crossover trial with conditions of fitted, thin, and standard condoms. A permuted block randomization scheme was used to assign each participant to the sequence in which they received each type of study condom. After a baseline screening and enrollment visit, randomized participants were followed for at least 6 and up to 12 weeks depending on their use of study condoms in each 2-week period between scheduled, in-person study visits. Participants were instructed to complete mobile-optimized coital logs as soon as possible after using condoms for anal or vaginal sex acts. The logs collected event-level pleasure and performance measures for the study condoms as well as other relevant data. A questionnaire was administered at the final study visit to assess overall study condom preference.

Results

The study enrolled 252 MSM and 252 MSW, a total of 504 participants. MSM and MSW study arms were similar for a number of key traits including race and ethnicity, marital status, self-rated condom experience, and recent experience of condom failure. Men in the MSM arm were older, however, and fewer MSM were students. The majority of participants in both arms rated themselves as very experienced with using condoms, and the majority had used condoms recently. Over one-third of participants in each arm reported experiencing condom failure in the last 6 months.

Conclusions

This is the first condom trial to compare the performance of standard, thin, and fitted condoms and to use pleasure and preference as primary outcomes. Given the disparate impact of HIV on MSM, equal enrollment of MSM and MSW was a key feature of this study. Trial results may inform an FDA label indication for anal sex and provide new information regarding the relative performance of different types of condoms.

Trial Registration

ClinicalTrials.gov NCT02753842; https://clinicaltrials.gov/ct2/show/NCT02753842 (Archived by WebCite at http://www.webcitation.org/76RLTFyf0)

International Registered Report Identifier (IRRID)

DERR1-10.2196/12205

Performance and safety of the second-generation female condom (FC2) versus the Woman's, the VA worn-of-women, and the Cupid female condoms: a randomised controlled non-inferiority crossover trial

BACKGROUND

New designs of female condom have been developed to reduce costs and improve acceptability. To secure regulatory approvals, clinical studies are needed to verify performance. We aimed to assess the functional performance and safety of three new condom types-the Woman's Condom, the VA worn-of-women (wow) Condom Feminine, and the Cupid female condom-against the existing second-generation female condom (FC2).

METHODS

We did a randomised controlled, non-inferiority, four-period crossover trial at three sites in Shanghai, China, and one site in Durban, South Africa, between May 1, 2011, and Jan 31, 2012. Participants aged 18-45 years who were sexually active, monogamous, not pregnant, and not sex workers, were eligible for inclusion if they were literate, had no known allergies to the study products; used a reliable, non-barrier method of contraception, and had no visible or reported sexually transmitted infections. We used a computer-generated randomisation sequence with a Williams square design of size four to assign patients (1:1:1:1) to the FC2 control device, or the Woman's, VA wow, or Cupid condoms, with 12 potential allocations. Randomisation was stratified by site. Participants were not masked to condom type, but allocation was concealed from study investigators. The primary non-inferiority endpoints were total clinical failure and total female condom failure, with a non-inferiority margin of 3%. Women were asked to use five of each condom type and were interviewed after use of each type. We also assessed safety data for each type. We did both per-protocol and intention-to-treat analyses. We calculated frequencies and percentages for each failure event and estimated differences in performance with a generalised estimating equation model. This study is registered, number DOH-27-0113-4271.

FINDINGS

616 women were assessed for eligibility, of whom 600 were randomly assigned to condom-type order (30, 120, and 150 women in the three sites in China, and 300 women in the site in South Africa). 572 women completed follow-up, with at least one condom of each type. Total female condom failure was 3·43% for FC2, 3·85% for the Woman's Condom (difference 0·42%, 90% CI -1·42 to 2·26), 3·02% for VA wow (-0·42%, -1·86 to 1·32), and 4·52% for Cupid (1·09%, -0·60 to 2·78); total clinical failure was 2·88%, 3·05% (0·17%, -1·48 to 1·81), 2·49% (-0·25%, -1·75 to 1·26), and 3·87% (0·99%, -0·55 to 2·52), respectively. Only two (<1%) participants, in South Africa, reported serious adverse events, unrelated to use of the study products.

INTERPRETATION

Non-inferiority was shown for all condom failure events for the three new devices versus the FC2, within the predefined margin.

FUNDING

Universal Access to Female Condoms (UAFC).

Condom type may influence sexual behavior and ejaculation and complicate the assessment of condom functionality

BACKGROUND

Studies that evaluate condom effectiveness are affected by factors related to how the condom was used, and these factors may not be consistent between different types of condoms. Also, subjective assessments of the sexual act may be unreliable.

STUDY DESIGN

We performed a secondary data analysis of a randomized crossover trial of male and female condoms among 108 couples.

RESULTS

Self-reported duration and activeness of coital acts were significantly different for uses of the male condom compared to uses of the female condom. Fewer individuals reported ejaculation occurring with the female condom. Reliability of self-reports of ejaculation compared to a biological marker of semen detected inside the used male and female condoms was not strong.

CONCLUSIONS

We found that sexual behaviors appear to differ by the type of condom used for the coital act. Studies should consider sexual behavior when evaluating condom effectiveness. Furthermore, studies would be strengthened by the use of a biological marker of semen to determine whether ejaculation, and therefore a true risk of exposure, occurred.

Condom use around the globe: how can we fulfil the prevention potential of male condoms?

Despite a global epidemic of sexually transmissible infections and the availability and endorsement of condoms as an effective intervention, the overall use of condoms remains low. This review explores various challenges and opportunities to fully realizing the prevention potential for condoms.