A study published in the most recent issue of the Wisconsin Medical Journal (Volume 107, No. 7) found half of the 252 women surveyed at two different family practice clinics incorrectly thought condoms were 99 percent effective.
Only 57 percent knew that condoms were not as effective as the pill.
Researchers at the Department of Family Medicine at the University of Wisconsin School of Medicine and Public Health conducted the survey.
In other findings, 59 percent of the respondents also were unaware that birth control pills can decrease the risk of some types of cancer (uterine and ovarian) and 21 percent incorrectly said that IUDs are unsafe.
"Women in this study demonstrated some important gaps in their knowledge about commonly used contraceptive methods," the authors write.
Given that half of all pregnancies are unintended and half of all unintended pregnancies are aborted, the researchers suggest greater education regarding contraception would be worthwhile in the clinic setting.
"Clearer educational materials and patient-centered counseling about pregnancy readiness, attitudes toward contraception, and all the contraceptive options need to be emphasized in primary care offices," authors conclude.