Medline ® Abstracts for References 52-54

This review provides an update of previous estimates of first-year probabilities of contraceptive failure for all methods of contraception available in the United States. Estimates are provided of probabilities of failure during typical use (which includes both incorrect and inconsistent use) and during perfect use (correct and consistent use). The difference between these two probabilities reveals the consequences of imperfect use; it depends both on how unforgiving of imperfect use a method is and on how hard it is to use that method perfectly. These revisions reflect new research on contraceptive failure both during perfect use and during typical use.

OBJECTIVE: To establish the continuation rates of the levonorgestrel intrauterine system (LNG IUS) and symptoms associated with its premature removal.

SAMPLE AND SETTING: All women in Finland who had a LNG IUS inserted between April 1990 and December 1993 and whose doctor had filled in and returned a form at the insertion visit. This study population consists of 46% of all the LNG IUSs sold in Finland between 1990 and 1993.

DESIGN: A questionnaire on reproductive and contraceptive history, gynaecological problems and symptoms experienced during the use of the LNG IUS was sent to 23,885 LNG IUS users. A total of 17,914 questionnaires were returned (response rate 75%). The results cover experience from 58,600 woman years. A log-rank-test was used to test differences in continuation rates. Multivariate analyse were performed using Cox's proportional hazard model.

RESULTS: The LNG IUS was prematurely removed from 5175 women. The one, two, three, four and five year continuation rates were 93%, 87%, 81%, 75% and 65%, respectively. The symptoms during the use of the LNG IUS most strongly associated with its premature removal were excessive bleeding and spotting, and infections and pain. The risk of premature removal was markedly lower among women who had occasional or total absence of menstruation. Premature removal was less likely in the oldest age group.

CONCLUSIONS: The continuation rate of the LNG IUS compares favourably with other long-acting contraceptive systems. Totally or occasionally absent menstruation was strongly associated with prolonged continuation.

The Contraceptive CHOICE Project (CHOICE) sought to reduce unintended pregnancies in the St. Louis Region by removing cost, education, and access barriers to highly effective contraception. CHOICE was a prospective cohort study of over 9,000 women 14-45 years of age who received tiered contraceptive counseling to increase awareness of all reversible methods available, particularly long-acting reversible contraceptive (LARC) methods. Participants were provided with contraception of their choice at no cost for 2-3 years. We studied contraceptive method choice, continuation, and population outcomes of repeat abortion and teen pregnancy. Seventy-five percent of study participants chose one of the three LARC methods (46% levonorgestrel intrauterine system, 12% copper intrauterine device, and 17% subdermal implant). LARC users reported greater continuation than non-LARC users at 12 months (87% versus 57%) and 24 months (77% versus 41%). In our cohort, LARC methods were 20 times more effective than non-LARC methods. As a result, we observed a reduction in the percent of repeat abortions from 2006 to 2010 in St. Louis compared with Kansas City and nonmetropolitan Missouri and found substantial reductions in teen pregnancy, birth, and abortion (34.0, 19.4, and 9.7 per 1000 teens, respectively) compared with national rates among sexually experienced teens (158.5, 94.0, and 41.5 per 1000, respectively). Improved access to LARC methods can result in fewer unintended pregnancies and abortions and considerable cost savings to the health care system.