Patch is as effective as pill; weekly dosing schedule may improve compliance.

Abstract

A study in the US and Canada involving 1400 women indicated the contraceptive effectiveness of patch as comparable to that of combined oral contraceptive. The women were randomly assigned to either patch or oral contraceptive for 6 or 13 cycles and contraceptive efficacy was measured by calculating overall and method-related Pearl Indices and cumulative probabilities of pregnancy. Results noted no significant difference in womens experience with breakthrough bleeding with the 2 methods. Moreover the probabilities of pregnancy were similar among women who used the patch and those who used the pill (1-2% over 13 cycles). The types of adverse reactions were also noted to be similar between groups. Although Pearl Indices were numerically lower among users of patch than among women who used the pill differences were statistically insignificant. Furthermore contraceptive compliance was associated with contraceptive efficacy in which womens compliance with using the patch was significantly higher than that with using the pill.