[Emergency contraception].

Emergency contraception is indicated when no birth control is used or in case of contraception failure. To day, two methods of emergency contraception are available. The hormonal method consists in taking a tablet of levonorgestrel 1.

Accounting for time: insights from a life-table analysis of the efficacy of medical abortion.

Objective: Previously published analyses have ignored the temporal nature of medical abortion and calculated effectiveness as the proportion of abortions that succeed. By using life tables, we incorporate the important element of time to produce unbiased efficacy rates as well as afford insight into the medical abortion process.

Study Design: Using data on 6568 women from 6 previously published mifepristone-misoprostol medical abortion studies, we generated multidecrement life table efficacy curves and evaluated the cumulative probability of successful medical abortion.