Awareness of long-acting reversible contraceptives (LARCs) such as IUDs and implants remains relatively low, while misperceptions about their effectiveness and safety are common among U.S. women between the ages of 18 and 44, a report from the Urban Institute finds. Based on surveys, the report, Knowledge Gaps and Misinformation About Birth Control Methods Persist in 2016 (16 pages, PDF), found that respondents were less likely (34 percent) to have heard a lot about implants and more likely (20 percent) to have heard nothing about them than about any other method, including the rhythm method, shots, and hormonal rings and patches. Although implants have been shown to be most effective — 0.05 percent of implant users become pregnant during a year of typical use, compared with 0.5 percent for tubal ligation, 0.8 percent for copper IUDs, 9 percent for birth control pills, and 18 percent for male condoms — only 37 percent of respondents believed implants were very effective, while 32 percent said they did not know how effective they were. The study also found a significant percentage of respondents reporting uncertainty about the safety of many methods, including hormonal rings (31 percent), implants (30 percent), patches (28 percent), emergency contraception (27 percent), and IUDs and shots (23 percent). Funded by the William and Flora Hewlett Foundation, the report suggests that younger women between the ages of 18 and 25 and black, uninsured, and low-income women are more likely to have a "LARC knowledge gap" and calls for further outreach and education to reduce unintended pregnancies.