Strengths and limitations
bacterial vaginosis, pelvic inflammatory disease, thrush
PELVIC INFLAMMATORY DISEASE, SECONDARY, BACTERIAL VAGINOSIS, BLIND, THRUSH
VITA was a large trial which included an ethnically diverse patient population. The trial was pragmatic and reflected common clinical practice ensuring that our results are likely to be widely applicable.We recognise several potential limitations. It was not possible to blind participants or clinicians to the treatment allocation which raises the possibility of reporting bias. However, we think bias is unlikely because a pre-planned secondary analysis of outcomes based on microscopy findings (performed by technicians who were blind to treatment allocation) showed a similar, if slightly larger, difference in treatment efficacy compared to the primary analysis of participant reported symptoms.The self-reporting of patient symptoms may have overestimated the number of women with bacterial vaginosis and this may have occurred more commonly in those women in the metronidazole arm who were at greater risk of developing thrush type symptoms. However, microbiological confirmation of bacterial vaginosis at baseline occurred in 84% of participants according to local laboratory analysis (which would apply in routine practice) and 51% in a central laboratory analysis suggesting that our findings remain clinically relevant. It is likely that women with microbiological evidence of bacterial vaginosis in the absence of symptoms are at increased risk of pelvic inflammatory disease and adverse pregnancy outcomes but it is not known whether treating bacterial vaginosis in this scenario can improve outcomes and further clinical trials are required to address this.We allowed use of any lactic acid gel dispensed in 5 ml applicators, with the decision regarding the actual brand delegated to the investigator. Participants reported use of just two brands, which both contained 4.5% lactic acid balanced to ph3.8 and the same excipients which were both commercially available. It is therefore highly likely that the effectiveness of these products were similar. Theoretically the effectiveness could differ if factors such as the lactic acid isomer ratio [The loss to follow-up rate for collection of the primary endpoint was 21% compared to a predicted rate of 10% [