46 mm size vaginal ring most preferred and had maximum adherence among women, suggests study

Key findings

• The findings also highlighted user preference, where at the study's conclusion, 59% of participants preferred the smallest ring (46 mm), whereas only 18% preferred the 56 mm and 66 mm rings (p=0.0045).

• Adherence rate: There were no significant differences in adherence across any of the rings, wherein adherence was reported to be generalized at 78%, 75%, and 59% for the 46 mm, 56 mm, and 66 mm rings, respectively (p=0.30).

• Expulsions and removals: Compared to the 56 mm ring, expulsions were found to be more likely for both the 46 mm ring (OR 5.72, 95% CI: 1.25-26.1) and the 66 mm ring (OR 25.9, 95% CI: 6.11-109).

• Greater odds of being out (removal or expulsion) were reported for the 66 mm compared to the 56 mm (OR 6.50, 95% CI: 3.46-12.2).

• Acceptability scores were the same statistically, with 46 mm and 56 mm rings receiving a rating of 4.54/5, which was also significantly higher than that of the 66 mm, rated 3.94/5 (p<0.001).

The study confirms the importance of acceptability and functionality for the vaginal ring diameter of 54-58mm used mainly; though the most preferred is the 46mm, less expulsion was noted in the 56mm ring with equal acceptability. Future studies need to look into different parameters, similar to the physical attributes of the vaginal rings, for optimizing the future designs of the ring across larger populations.

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