Volume 33, Number 2, March/April 2001
Contraceptive Use Elevates The Odds of Barrier Method Use for Disease Prevention
Low-income women with a high risk of acquiring a sexually transmitted disease (STD) are more likely to use condoms or spermicides for STD prevention if they have been using contraceptives, particularly barrier methods, than if they have not been practicing birth control, according to results of a study conducted in an urban Alabama STD clinic.1 However, all women--including those originally using no contraceptive--increased their use of barrier methods after participating in an intensive program promoting the use of such methods for STD prevention. The proportion reporting consistent use of a barrier method rose from 46% to 48% among those who had been using barrier contraceptives, from roughly 20% to 40% among users of other contraceptive methods and from 7% to 33% among women who had been using no birth control.
Study participation was open to women attending the clinic between 1992 and 1995 who were aged 18-34, were not pregnant or planning to become pregnant in the next six months and had not had a hysterectomy. The women were interviewed extensively and instructed in how to use a sexual diary; in addition, a nurse provided detailed information about the importance of consistent, correct use of barrier methods to prevent STDs. Participants were encouraged to use a condom and vaginal spermicide together or, if that was not possible, a condom alone. They were given free supplies and were asked to return to the clinic for six monthly follow-up appointments.
In all, the researchers analyzed data on 991 women, nine in 10 of whom were black. At the beginning of the study, 37% of participants relied on a birth control method that was independent of user behavior (tubal ligation or an IUD, implant or injectable), 28% used oral contraceptives, 23% used barrier methods (condom, spermicides, diaphragm or sponge) and 11% used no birth control. Results of multinomial regression analyses revealed that these groups had significantly different backgrounds. Women relying on user-independent methods tended to be older and to have lower levels of education and income than women in the other groups; they also were more likely than others to be married or living with a partner. Women using oral contraceptives tended to have higher education and income than other women. Those using barrier methods or no method generally fell in the intermediate range on these measures; however, women using barrier methods were younger, had higher incomes and were more likely to be single than those using no method.
Participants' sexual and medical history also varied according to their contraceptive use. Women who reported at the baseline interview that they relied on user-independent methods had become pregnant at younger ages and had more children than women in the other groups. Pill users had been oldest at first intercourse, had had the fewest lifetime sexual partners and were the least likely to have had an STD. Compared with women in other groups, users of barrier methods had fewer children and had had more sexual partners during the previous month. Women using no method had the youngest age at first intercourse and the highest number of lifetime partners; however, they were the least likely to have had intercourse during the previous month.
Some 891 women said that they had had intercourse in the 30 days prior to entering the study. In this group, 46% of women who reported that they used barrier methods of birth control said that they had used such methods every time they had sex in the previous month; 12% reported not having used a barrier method within the last month. By contrast, 26% of pill users, 20% of other contraceptive users and 7% of women who used no birth control had used barrier methods consistently during the previous month, while 41-49% of contraceptive users and 66% of nonusers had not used a barrier method. Levels and patterns of condom use in the last 30 days were similar to those for overall barrier method use; no more than 10% of women in any contraceptive category had used spermicides.
Analyses based on the 747 women who made at least one follow-up visit and reported having had intercourse both in the month before they entered the study and at some time since show improvements in barrier method use for all groups. Women who had used barrier contraceptives remained the most likely to use barrier methods consistently (48%). Levels of consistent barrier method use rose to 41% among pill users, 36% among users of other contraceptive methods and 33% among women who had initially reported using no birth control. The proportions reporting no use of barrier methods during the follow-up period were low--5% of women who had not used a contraceptive before entering the study and 1% of all other groups.
Cumulative logit regression analyses indicated that the odds of consistent use of barrier methods were elevated among women who were older than 25, had 12 or fewer years of education or were single (odds ratios, 1.2-1.5). The odds were reduced as a woman's number of children grew (0.7) and among those who had had an STD (0.6). Women who had used a contraceptive method at baseline were more likely than those who had not to use a barrier method consistently at follow-up; odds ratios ranged from 1.3 among users of oral contraceptives to 1.7 among users of barrier methods.
According to the investigators, the high level of use of barrier methods for STD prevention among women who had relied on barrier contraceptives before the intervention may indicate that these women were already consistent users. However, they point out, the program improved barrier method use among all women; notably, the findings indicate that even women who do not practice birth control can be reached and motivated to adopt barrier methods for STD prevention. The researchers conclude that "the potential synergism between the intention to prevent pregnancy and the intention to prevent STD should be considered in the design of interventions promoting condom use."--M.L. O'Connor
1. Macaluso M, Cheng H and Akers R, Birth control method choice and use of barrier methods for sexually transmitted disease prevention among low-income African-American women, Contraception, 2000, 62(1):5-13.