Women who rely on a user-independent highly effective method of contraception (IUD, injectable or implant) are less likely than those who rely on a user-dependent method (the pill or patch) to further protect themselves by concurrently using condoms, according to an analysis of data from the National Survey of Family Growth (NSFG).1 Among women who reported using a highly effective method during the month they were interviewed, the proportion of pill users who also used condoms was greater than the proportions of injectable users and IUD and implant users who did so (18% vs. 15% and 2%, respectively); a similar pattern was found among women who reported using a highly effective method at last sex in the past three months (15% vs. 11% and 2%, respectively). An estimated 393,000 unplanned pregnancies and 76,000 abortions would be avoided each year if half of women who used a highly effective method used condoms concurrently; if all women who used a highly effective method used condoms, twice as many unplanned pregnancies and abortions would be avoided.

Researchers used the nationally representative NSFG data to examine dual contraceptive behavior among two groups of 15–44-year-old women: 1,561 who reported using a highly effective contraceptive method during the month in which they were interviewed, and 1,552 who reported using such a method at their last intercourse in the prior three months. Women were not included in either sample if they reported being sterile or having a sterile partner; women were not included in the interview-month sample if they had not had sexual intercourse in the prior three months. Logistic regression analyses were conducted to determine women’s odds of condom use by whether they relied on a user-dependent or a user-independent highly effective method.

Among women in the interview-month group, the proportion of pill users who also used condoms was greater than the proportions of injectable users or IUD and implant users who did so (18% vs. 15% and 2%, respectively); a similar pattern was found among the last-intercourse group (15% vs. 11% and 2%, respectively). Across subgroups defined according to age, partner status, race, household income and education, the level of dual contraceptive behavior was greater among women who relied on a user-dependent method than among those who relied on a user-independent method.

In analyses controlling for social and demographic characteristics, women who were 25 or older had lower odds than 20–24-year-olds of using condoms with a user-dependent method (odds ratios, 0.3 for the interview-month group and 0.5 for the last-intercourse group). In both groups, married women who had had only one partner in the past year were less likely than women who had had multiple partners to use condoms with either a user dependent or a user-independent method (0.03–0.3). Among women in the interview-month group who relied on a user-independent method, Hispanics had greater odds than blacks of using condoms (9.3); among women in the last-intercourse group who relied on a user-independent method, those who had greater than a high school education had lower odds than less educated women of using condoms (0.1).

In further multivariate analyses, among white and black women in the interview-month group, those who relied on a user-independent method were less likely than those who relied on a user-dependent method to also use condoms (odds ratios, 0.4 and 0.1, respectively); there was no difference in dual method use among Hispanics. Women in the last-intercourse group who had at least a high school education were less likely to use condoms along with a user-independent method than with a user-dependent method (0.5); women without a high school diploma had even lower odds of such behavior (0.03).

The researchers also used annual pregnancy rates for each contraceptive method to calculate the estimated numbers of unplanned pregnancies and abortions that would be avoided if more women who relied on highly effective contraceptive methods concurrently used condoms. If half of these women also used condoms, an estimated 393,000 fewer unplanned pregnancies and 76,000 fewer abortions would occur each year—a reduction of 40%. If all practiced dual protection, 80% of unplanned pregnancies and abortions would be avoided.

The authors conclude from their analysis that “many women are placing themselves at risk for STDs and unplanned pregnancies that could be avoided by using condoms in addition to their more highly effective contraceptive method.” However, they point out that “promoting dual-method use will require that we overcome unique barriers, including…inconsistent condom use or abandonment of condoms with the adoption of a second, more highly effective contraceptive method” and “the negative association of condoms as a method for preventing [STDs] that acknowledges the potential for infidelity and distrust within a relationship.”

—J. Rosenberg

REFERENCES

1. Pazol K, Kramer MR and Hogue CJ, Condoms for dual protection: patterns of use with highly effective contraceptive methods, Public Health Reports, 2010, 125(2):208–216.