A randomized crossover trial of the impact of additional spermicide on condom failure rates

Opinions remain divided concerning the potential for additional water-based lubricant to reduce condom breaks and slips. We sought to explore impact of externally applied additional lubrication on condom failure rates among regular users in stable heterosexual relationships.

To compare condom failure rates with and without additional spermicide.

Couples randomized to use up to 70 condoms alone (control) or with additional spermicide (intervention), with midpoint crossover. Couple demographic and failure risk data collected at baseline. Follow ups at three and six months recorded condom failure events, spermicide acceptability, side-effects and adverse events. Condom failure rates were compared using an intention to treat analysis.

Altogether 12,530 condoms were used by 145 couples completing the trial, There were 45/6,463:0.70% (95% CI 0.51%-0.93%) clinical and nonclinical failures in the additional spermicide arm, compared to 111/6,067:1.83% (95% CI 1.51%-2.20%) during the control arm. The clinical condom failure rate was 0.53% (95% CI 0.41%-0.66%), with 19 (0.31%: 95% CI 0.18%-0.43%) during the additional spermicide arm, compared to 46 (0.77%: 95% CI 0.56%-0.99%) during the control arm. Couples experienced significantly lower total (P = 0.017) and clinical (P = 0.042) condom failure rates during the additional spermicide arm. Furthermore additional spermicide significantly reduced clinical failures among the 101 couples who'd experienced a previous condom failure (P = 0.002). There were 22 urinary tract infections, equally divided between the control and additional spermicide arms, however 10 of the 12 genital irritation episodes occurred with additional spermicide (P = 0.021).

Additional water-based external lubricant significantly reduced condom failures despite low failure rates among this stable, experienced group of condom users. Our results suggest that this may be a useful supplement to condom use, particularly among couples who experienced condom failures previously.