A Cochrane review included four studies with a total of 136 subjects. Two studies compared the use of plugs versus no plugs, one study compared two sizes of the same brand of plug, and one study compared two brands of plugs. In all included studies there was considerable dropout (in total 35%) for varying reasons. ”Pseudo-continence” was achieved by some of those who continued to use plugs, at least in the short-term. In a comparison of two different types of plug, plug loss was less often reported and overall satisfaction was greater during use of polyurethane plugs than polyvinyl-alcohol plugs.
Comment: The quality of evidence is downgraded by study quality (unclear allocation concealment and more than 20% loss to follow-up) and by imprecise results (limited study size for each comparison).