Summary of "Three-Year Continuation of Reversible Contraception," Justin Diedrich et al., American Journal of Obstetrics & Gynecology, Aug. 7, 2015.
"Long-acting reversible contraceptive (LARC) methods are highly effective and have high user satisfaction," Justin Diedrich, of the Department of Obstetrics and Gynecology at the Washington University School of Medicine in St. Louis, and colleagues noted. Further, use of LARC has grown "5-fold ... over the last decade," with about "8.5% of women who use contraception report[ing] current use of a LARC method," the researchers added. Moreover, women who use LARCs "are likely to be highly satisfied with their method at 12 and 24 months."
However, data about continuation of LARC use at three years among women in the U.S. "are lacking," the researchers wrote. They conducted the study to estimate "36-month continuation of [a] baseline contraceptive method" chosen by study participants; to "compare continuation rates of LARC and non-LARC methods" and to "explor[e] baseline characteristics that are associated with discontinuation of contraceptive methods."
Methods
According to the researchers, the study was part of the Contraceptive CHOICE Project, which aimed "to reduce the unintended pregnancy rate in the St. Louis, Mo., area by promoting the most effective methods of contraception and eliminating the cost barrier to all forms of contraception." Researchers recruited 9,256 participants between 2007 and 2011. Eligible participants:
~ Were able to consent in English or Spanish
~ Ranged in age from 14 to 45;
~ Were sexually active with a male partner or planned to be within six months;
~ Lived in or received reproductive health care in the St. Louis area; and
~ Wanted reversible contraception and were willing to use a new method.
The study was not open to women who desired pregnancy within the next year or who had permanent sterilization.
All participants received contraceptive counseling and then selected their preferred contraceptive. LARC methods included:
~ A copper intrauterine device (Cu-IUD);
~ A levonorgestrel IUD (LNG-IUD); and
~ A subdermal implant.
The study also included participants who used non-LARC methods, including:
~ The contraceptive patch;
~ Depot medroxyprogesterone acetate (DMPA);
~ Oral contraceptive pills; and
~ The vaginal ring.
Researchers provided participants with their preferred contraceptive method at no cost. Participants were tracked for two or three years via telephone calls at three months, six months and then every six months through the duration of the study. Participants could change methods at any point during follow-up.
In the analysis, the researchers included women who started using their preferred contraceptive method by month three of the study "and completed their 36-month follow-up survey or had another data source that verified continuation or discontinuation at three years."
Results
The final analysis included 4,708 participants. The cohort included 644 adolescents, 405 of whom opted for LARC methods and 239 of whom selected non-LARC methods.
In their analysis, the researchers "noted that LARC users were older, had higher parity, were more likely to have public insurance, and were more likely to have a history of unintended pregnancy." Among LARC users, 67.2% were using the baseline method at the three-year mark. By contrast, the rate was 31% among non-LARC users. IUD users had the "highest continuation" rate, with a rate of 69.8% among LNG-IUD users and 69.7% among Cu-IUD users. By contrast, the three-year continuation rates among non-LARC users spanned from 28% to 32%.
Meanwhile, the researchers found the three-year continuation rate "was lower for all methods" among users in the 14-19 age cohort than among those in the 20-45 age cohort, with adolescents using non-LARC methods having the lowest continuation rate. Specifically, the three-year continuation rate was 23.1% among adolescents who used non-LARC methods compared with 52.6% among those who used LARC.
Among adolescents who used LARC, the three-year continuation rate was:
~ 54.6% among LNG-IUD users;
~ 49.5% among Cu-IUD users; and
~ 50.8% among subdermal implant users.
The researchers noted, "After adjustment for age, race, education, low socioeconomic status, parity, and history of sexually transmitted infection, the hazard ratio for discontinuation was >3 times higher among non-LARC method users ... than LARC users." The researchers added that "college graduates reported a lower risk of discontinuation" than "those with a high school education or less."
According to the researchers, reasons why participants stopped using the baseline method varied. Among LARC users:
~ 19% of LNG-IUD users who stopped using the device "did so because of bleeding changes," while "25% reported 'I did not like how it made me feel'"; ~ 35% of Cu-IUD users who stopped using the device did so because of "bleeding changes," while 17% stopped because of cramping; and ~ 45% of implant users who discontinued the implant did so because of bleeding changes, while "28% reported that they did not like how they felt."
Meanwhile, among non-LARC users:
~ "33% of DMPA users who stopped this method reported general side effects as the most common reason for discontinuation";
~ 42% of people who stopped using oral contraceptives discontinued because of "logistical reasons, such as the pill being hard to remember to get or to take";
~ 41% of those who stopped using the patch did so because of side effects; and
~ 27% of those who stopped using the ring "reported side effects," while "24% reported logistical issues."
Discussion
"Continuation rates for LARC methods at 1, 2, and 3 years are significantly higher than non-LARC methods," the researchers wrote, noting that "choice of a short-acting method and younger age were associated with increased discontinuation."
However, they reiterated that even though teens "were more likely to discontinue than women" who were at least 20 years old, "more than one-half" of adolescents who selected LARC "were still using their method at 3 years compared with one-fifth of adolescents" who did not select a LARC method. Moreover, the researchers noted, "Even among women who were using short-acting methods, 3-year continuation was relatively high," ranging from 28% to 33% in their study.
Among LARC users, "[t]he 70% continuation of both LNG- and Cu-IUDs was consistent with the previously reported 67-80%," the authors wrote. Meanwhile, "The 56% continuation of implants was higher than the previously reported 30-53%," according to the authors.
The authors noted, "It is very plausible that women who are interested in long-term (>2 years) protection from pregnancy are more likely to select IUDs and the implant," while those "who are less certain about their need or desire for long-term contraception would select non-LARC methods." Nonetheless, the authors wrote that they "still believe [their] estimates of 3-year continuation are important for contraceptive counseling" as "[h]igh continuation rates reflect high satisfaction with LARC methods."
According to the researchers, "Regardless of age, sociodemographic markers, and education, women who use LARC methods report high continuation rates at 3 years," but oral contraception "and condoms continue to be the most commonly used reversible contraceptive methods used by women in the United States." They add, "It is time for a paradigm shift: LARC methods should be considered first-line contraceptives for women of all ages."
