Systematic Review of Randomized Trials of Treatment of Male Sexual Partners for Improved Bacteria vaginosis Outcomes in Women

Background: Bacterial vaginosis (BV) affects 10-30% of women and recurs in 15-30% within 3 months after treatment. BV is not considered an STI and treatment of the male sexual partner is not recommended. This recommendation is based on the results of 6 randomized controlled trials (RCT) of male partner treatment for reducing BV recurrence, which did not find a uniformly beneficial effect. These results are incongruous with epidemiologic and microbiologic data suggesting a sexually transmissible component of BV. In light of this disconnect, the 6 RCTs of male treatment were reviewed to assess validity. Methods: Trials are summarized according to CONSORT guidelines. Absolute differences and risk ratios (RRs) with binomially obtained 95% confidence intervals (CIs) were estimated. Post-hoc power analyses determined the probability of rejecting the null hypothesis for observed relative effect sizes and for the smallest relative effect size detectable with >80% power. Results: Each of the 6 RCTs had significant flaws: randomization methods were either overtly deficient or insufficiently reported; 5 RCTs used sub-optimal treatment regimens in women; adherence to treatment in women was not reported in any trial and adherence in men was reported in only 2 trials; all 6 trials had limited power. None assessed whether antibiotic treatment affected the penile microbiota. Conclusions: While the RCT is the gold standard for assessing efficacy, biased results can mislead decision making. By current standards, it is unlikely that the results of any of these trials would be considered conclusive. Specific recommendations are made to examine whether BV-associated bacteria may be sexually transferred.