Study suggests more than socioeconomic factors at work when choosing birth-control methods

A recent study of sexually-active women in California finds that socioeconomic status does not fully explain why certain groups of women in the Golden State use more effective birth-control methods than others, according to a report published in the September 2011 issue of Perspectives on Sexual and Reproductive Health, a reproductive-health journal published by the Guttmacher Institute. What also accounts for such disparities, researchers Grace Shih, Eric Vittinghoff, Jody Steinauer and Christine Dehlendorf found, is race and ethnicity.

Using data from the 2006-2008 California Women’s Health Survey, the researchers studied approximately 3,000 women ages 18 to 44 and discovered that African-American and foreign-born Asian women were at a higher risk than white women of becoming pregnant unintentionally because of the types of contraceptive methods they were using. To come to this conclusion, birth-control method choice was compared to the subjects’ racial, ethnic, demographic and socioeconomic characteristics.

The research team identified the following contraceptive methods, ranked in descending order of effectiveness: male sterilization, female sterilization, intrauterine devices (IUDs), implants, injectables, vaginal ring, patch, pill, male condoms, other regular methods (i.e., spermicide, natural family planning), emergency contraception only and none. IUDs and hormonal methods were classified as “high-efficacy” and all other methods as “low-efficacy.”

(The report notes that female and male sterilization methods and the IUD have failure rates of less than 1 percent; birth control methods such as the ring, patch and pill have failure rates of 5-9 percent; and condoms have typical failure rates of 17-18 percent. However, according to the Centers for Disease Control and Prevention (CDC), condoms can be 98 percent effective if used correctly.)

When controlling for demographic and socioeconomic characteristics, the study team found that:

• Blacks, foreign-born Hispanics and foreign-born Asians had lower odds than whites of using “high-efficacy” reversible methods.
• Of all the racial groups, white women were the least likely to report using no contraceptive method during sex (19 percent), while black women were the most likely to report using no method (28 percent).
• Whites were more likely to rely on male sterilization than were other sub-groups, especially foreign-born Asians (16 percent). U.S.-born and foreign-born Asians were less likely to use female sterilization (2 percent and 4 percent, respectively) than were others (8–17 percent).
• U.S.-born Asians were more likely to use the hormonal birth control pill than any other racial group (28 percent); pill use was least common among blacks and foreign-born Hispanics (16-17 percent).
• Condoms were used most among U.S.- and foreign-born Asians (25 percent and 36 percent, respectively) and least among whites (16 percent).
• Overall, 21 percent of women reported not using any contraceptive method. Women were most likely to use the pill (23 percent) or condoms (20 percent), followed by male or female sterilization (10 percent for both) and IUDs (8 percent), followed by injectables (3 percent), the ring (2 percent) and the patch (1 percent).

Ethnic disparities were not found, however, in the use of IUDs, the report found.

The data also revealed that differences in income level also accounted for contraceptive method choice.

• Women in the highest income category were more likely to rely on male sterilization (15 percent vs. 2–6 percent in lower income groups) or the pill (26 percent vs. 17–18 percent) and less likely to report not using any contraception (19 percent vs. 23–26 percent).
• High school graduates were more likely than non-high school graduates to report not using any birth control (21 percent vs. 25 percent).
• IUD and condom use differed little by income or educational level.

National studies, such as a recent Guttmacher Institute report, on unintended pregnancies among American women, have found disparities among socioeconomic group, but the California study suggests that other factors influence what type of woman uses (or does not use) a certain kind of birth control method.

Based on the findings, the researchers identified a need for further research of birth-control use among various minority groups, coupled with intervention programs that target minority groups at high risk for unintended pregnancy.

“Our study underscores the need for improved understanding of contraceptive behavior among minority women,” the researchers write. “Other potential influences on differences in contraceptive use by racial, ethnic and income characteristics include client knowledge of contraceptives and values regarding method choice. … Asian women are of particular interest because of the relative lack of reproductive health information on this population and their relatively low rates of use of high-efficacy methods.”