Combined estimates of effectiveness of XXXX 10 mg in emergency contraception.

@entity1 @entity3927 @entity390 @entity490
The present paper combines the estimates of efficacy and side effects of 10 mg @entity3927 for emergency contraception obtained from randomized trials. A total of 6083 @entity1 participating in 12 randomized trials and receiving 10 mg @entity3927 for emergency contraception up to 120 h after intercourse, were analyzed for efficacy. Between 4188 and 5833 @entity1 were analyzed for side effects and 3601 for delay of menses of more than 7 days. Prevented fractions, the effect of delay and of further acts of intercourse after treatment administration were analyzed in 3440 @entity1 , using individual data. The combined pregnancy rate from all the 12 trials was 1.7% [101/6083, 95% confidence interval (CI): 1.3-2.2]. From the three trials providing individual data, the combined pregnancy rate was 1.3% (45/3440, 95% CI: 0.9-1.7) and the estimate of pregnancies prevented was 83.4% (95% CI: 77.4-87.8). There was a sharp decline in efficacy when treatment was administered during the 5th day after intercourse compared to administration during the 1st day, the odds of pregnancy increasing by a factor of 5.3 (95% CI: 1.9-14.9). The relative risk of pregnancy was about 28 times higher among @entity1 with unprotected acts of coitus between treatment administration and the onset of next menses, compared with @entity1 reporting none [odds ratio (OR) = 27.6, 95% CI: 12.7-60.2]. The increase in risk for @entity1 reporting protected acts of intercourse during this interval was not statistically significant (OR = 1.8, 95% CI: 0.9-3.8). There was a large heterogeneity among trials in all side effects and delay of menses of more than 7 days (all had p < 0.0001 for the test of homogeneity). The percentage of @entity1 with @entity390 ranged from 0.0-19.4% (highest upper 95% confidence limit: 23.0%), that of vomiting from 0.0-4.3% (highest upper 95% confidence limit: 6.1%), that of lower @entity490 from 4.3-19.1% (highest upper 95% confidence limit: 22.7%). The percentage of @entity1 with delay of menses of more than 7 days ranged from 4.3-25.8% (highest upper 95% confidence limit: 34.1%). We conclude that 10 mg @entity3927 is an effective emergency contraception regimen, with an acceptable side-effects profile. Postponing treatment until the 5th day seriously decreases efficacy. The risk of pregnancy is dramatically increased among @entity1 having unprotected acts of intercourse between treatment administration and the onset of next menses. This risk may be enhanced for @entity1 whose ovulation is postponed by treatment.
