Randomisation and masking
bacterial vaginosis
VAGINA, BACTERIAL VAGINOSIS, BLIND
Delegated personnel in sites randomised participants 1:1 to lactic acid gel or metronidazole using a dedicated website maintained by Nottingham Clinical Trials Unit. Minimisation factors included: site, type of site (general practice, sexual health clinic), number of episodes of bacterial vaginosis in the previous 12 months (0, 1–3, > 3), and history of a female sexual partner in the previous 12 months (yes/no).Study treatment was provided from standard clinic stock or via a routine prescription. Any licensed brand of metronidazole or lactic acid gel could be used and was determined by local practice or availability. Participants took metronidazole tablets 400 mg orally twice daily for 7 days, or inserted 5 ml of 4.5% lactic acid gel into the vagina before bedtime each day for 7 days. Participants were advised to start treatment on the day of receipt. If they were menstruating, those assigned lactic acid gel were advised to delay starting treatment until menstruation had finished. Due to the different routes of administration, it was not possible to blind participants and clinicians to the randomised allocation. However, the trial team excluding members of the data management/IT team remained blinded to treatment allocation until the database was locked for the final analysis.