Characteristics of users of intrauterine devices and other reversible contraceptive methods in the United States

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1 CONTRACEPTION Characteristics of users of intrauterine devices and other reversible contraceptive methods in the United States Xin Xu, Ph.D., a Maurizio Macaluso, M.D., Dr.P.H., a Jennifer Frost, Ph.D., b John E. Anderson, Ph.D., a Kathryn Curtis, Ph.D., a and Scott D. Grosse, Ph.D. c a Division of Reproductive Health, Centers for Disease Control and Prevention, Atlanta, Georgia; b Guttmacher Institute, New York, New York; and c Division of Blood Disorders, Centers for Disease Control and Prevention, Atlanta, Georgia Objective: To evaluate the determinants of intrauterine device (IUD) use and reasons for choosing IUDs over other reversible contraceptive methods. Design: Descriptive statistics and multinomial logistic regression were used to assess multiple factors associated with IUD use and the use of other reversible methods in the United States. Setting: Not applicable. Patient(s): Women at risk of pregnancy from the 2006 to 2008 National Survey of Family Growth and a 2004 Guttmacher Institute survey. Intervention(s): None. Main Outcome Measure(s): Sociodemographic and reproductive characteristics, family background, and health insurance coverage. Result(s): IUD use was positively associated with women s parity and the highest education level of respondent s mother; it was less common among women who had R4 sexual partners in the last 12 months and those who were widowed, divorced, or separated. IUD users reported pregnancy prevention, provider recommendation, and no interruption of sex as the most important reasons for choosing the method and reported a high level of satisfaction. Conclusion(s): IUD users differed substantially from users of other reversible contraceptives. IUD use was especially uncommon among nulliparae. Most current IUD users were satisfied with their choice. (Fertil Steril Ò 2011;96: Ó2011 by American Society for Reproductive Medicine.) Key Words: IUD, reversible contraceptives, demographic characteristics, satisfaction, multinomial logistic regression Received June 10, 2011; revised and accepted August 12, 2011; published online September 13, X.X. has nothing to disclose. M.M. has nothing to disclose. J.F. has nothing to disclose. J.E.A. has nothing to disclose. K.C. has nothing to disclose. S.D.G. has nothing to disclose. Reprint requests: Xin Xu, Ph.D., NCCDPHP, CDC, 4770 Buford Highway, MS K-50, Atlanta, Georgia ( xinxu@cdc.gov). Half of all pregnancies (6.4 million) in the United States each year are unintended, and the total direct medical costs associated with these unintended pregnancies were estimated at 5 billion dollars in 2002 (1 3). The intrauterine device (IUD) is a safe, highly effective, long-lasting, and well-tolerated birth control method with excellent adherence (4 6). Despite these advantages, the prevalence of IUD use is relatively low in the United States (7, 8). Compared with 8% of European women of reproductive age who used the IUD in 2006 (9), 5.5% of US women of reproductive age were using the IUD for contraceptive purpose during 2006 to This percentage was up sharply from 1.3% in 2002 (10). An analysis of trends in IUD insertions among privately insured US women during this time period found that the majority of the increase was associated with uptake of the new levonorgestrelreleasing intrauterine system (LNG-IUS) that was introduced to the market in 2001, although there was also increased use of the regular copper T380A IUD (11). The relatively low US prevalence of IUD use can be traced to a specific historical event: in the 1970s, an early form of IUD, the Dalkon Shield, was marketed without adequate testing and led to serious safety problems and liability lawsuits (12, 13). Fearing further litigation, most IUD manufacturers had withdrawn from the US market by the mid- 1980s (14). Present-day IUDs, however, are small, risk free, and very effective (15). The LNG-IUS was first sold in 2001 and initially approved for up to 5 years of use. Although its efficacy and continuation rates are similar to those of the copper IUD (6, 8, 15), the LNG-IUS has led to a recent increase in insertion and usage of IUDs (11). Increasing use of the IUD in the United States could lead to fewer unintended pregnancies and substantial reduction in costs associated with unintended pregnancy (16). A better understanding of the characteristics of IUD users and their reasons for choosing the IUD is necessary to increase awareness of and access to this highly effective contraceptive method Fertility and Sterility â Vol. 96, No. 5, November /$36.00 Copyright ª2011 American Society for Reproductive Medicine, Published by Elsevier Inc. doi: /j.fertnstert

2 The objectives of this study were to describe sociodemographic and reproductive characteristics, family background, and health insurance coverage of IUD (including the LNG-IUS) users in the United States compared with users of other reversible methods and to describe the reasons provided for use of nd other reversible methods. MATERIALS AND METHODS Data We analyzed data from 2 sources: the 2006 to 2008 National Survey of Family Growth (NSFG) and a cross-sectional survey conducted by the Guttmacher Institute in The 2006 to 2008 NSFG sample included a total of 7,356 women aged 15 to 44 years. We excluded samples who had never had sex, as well as immigrants who moved to the United States between 2006 and 2008 because they might have obtained IUDs in other countries (n ¼ 6,177). We further restricted our sample to women using reversible contraceptive methods at the time of the interview (n ¼ 3,008). We also excluded from the sample 3 women who used implants because there were not enough implant users to categorize separately. A total of 3,005 women aged 15 to 44 years in the 2006 to 2008 NSFG were included in the final NSFG analysis sample. The Guttmacher Institute conducted telephone interviews during 2004 with a nationally representative, random sample of women aged 18 to 44 years who were at risk of unintended pregnancy. A 2-stage sampling process was used: first, nearly 30,000 households were identified from all 50 states and the District of Columbia through random digit dialing and screened for the presence of an age-eligible woman. In the second stage, female residents were excluded if they were currently pregnant or seeking pregnancy or had recently given birth at the time of the interview. In addition, the sample was restricted to women who reported heterosexual activity during the year and were able to become pregnant because they were not protected by their or their partner s sterilization or were sterile for other reasons. A total of 1,978 eligible women completed the 2004 interview conducted by the Guttmacher Institute, representing 75% of all eligible women. Using 2002 NSFG data, weights were created to adjust the Guttmacher Institute sample to reflect the distribution of all US women aged 18 to 44 years and at risk for unintended pregnancy. Among the 1,978 respondents in the Guttmacher Institute survey, 323 women who reported not using any contraceptives at the time of the interview were excluded. As a result of this exclusion, 1,655 women aged 18 to 44 years were included in the final Guttmacher Institute sample. Respondents to the Guttmacher Institute survey who were using a contraceptive method were asked their reasons for choosing their current method. Potential reasons were listed, and respondents were asked to rate them by importance, including very important, somewhat important, or not important. Respondents were also asked how satisfied they were with their current method (completely satisfied, somewhat satisfied, neutral, somewhat dissatisfied, or completely dissatisfied). Both samples used for this analysis contain only deidentified data. Thus, this analysis is research that does not involve human participants as defined by Title 45 Code of Federal Regulations, Part 46, and institutional review board approval was not required. Statistical Analysis Women in the 2006 to 2008 NSFG who were using a reversible contraceptive method at the time of the interview were divided into 5 categories according to the most effective method used, given the following hierarchy of methods: IUD (including the LNG-IUS), injectables, pills and patches, barrier methods (condom; diaphragm; female condom; vaginal pouch; foam, jelly, or cream; cervical cap; inserted suppository; and sponge), and other methods (e.g., withdrawal/pull out, rhythm, or safe period by calendar, planning, morning after pills or emergency contraception, ring). For each category, we reported descriptive statistics. The statistical significance of differences in the distribution of characteristics across the 5 categories of contraceptive methods was assessed with c 2 tests. In preliminary analyses, we used multiple logistic regression (IUD users vs. non-iud users; estimates not shown) with a stepwise backward selection model-building strategy to simultaneously evaluate potential predictors of IUD use and to estimate adjusted odds ratios (ORs) and their 95% confidence intervals (CI) as measures of association. The initial model specification included all variables that were statistically different across the 5 categories of contraceptive methods in descriptive analyses. During the model-building process, variables with contributions to the model that were P<.2 were excluded from the model. Some categories of the variables assessed in the descriptive analysis were collapsed for logistic regression models if, during the model-building process, none of the categories was statistically significant and if this improved model fit based on goodness-of-fit tests. In the final multivariate analysis, we used multinomial logistic regression to evaluate predictors of 5 categories of contraceptive methods. The likelihood ratio test rejected the hypothesis that any further combination of these 5 categories could be made. In the analysis, predictors of each of 4 contraceptive categories were compared independently with the reference group, IUD use. Design differences between the 2006 to 2008 NSFG and the 2004 Guttmacher Institute survey precluded using the same contraceptive categories. We grouped respondents from the Guttmacher Institute survey who used reversible contraceptive methods at the time of the interview into 4 groups: IUD (including both the copper nd the LNG-IUS), hormonal (including pills, injectables, patch, vaginal ring, and implants), condoms (male condoms), and others (including diaphragm, female condom, spermicides [jelly, foam, or cream], rhythm/natural, and withdrawal). We used z-tests to evaluate the statistical significance of pairwise comparisons of IUD users with the other 3 groups with respect to the reasons for their contraceptive choices. All analyses were weighted according to the sampling designs of the 2 surveys. RESULTS A total of 3,005 women who were using any reversible contraceptive methods at the time of their interview were identified from the 2006 to 2008 NSFG (Table 1). Based on the hierarchy of methods, 246 women (weighted percentage, 8.7) were classified as IUD (including LNG-IUS) users, 224 (5.2%) were users of injectables, 1,228 (43.4%) users of pills and patches, 914 (28.6%) users of barrier methods, and the remaining 393 (14.1%) were using other methods. Characteristics of Contraceptive Method Use Overall, IUD users had higher family incomes (43.4% with annual family income >$60,000 vs. 11.8% to 41.3% in the other 4 method groups), and a larger percentage was married (67.1% vs. 33.4% to 54.6% in the other 4 method groups). In addition, approximately one-fourth of IUD users were foreign born, higher than the percentage foreign born among users of other reversible methods (9.9% 18.9%). Compared with users of injectables, pills and patches, and barrier methods, IUD users were less likely to have no live births (1.5% vs. >29.0%). Users of IUDs and injectables were disproportionately likely to be of Hispanic origin (24.6%), compared with 11.4% to 16.8% among users of pills and patches, barrier methods, and other nonbarrier methods. Compared with injectable users, IUD users were significantly more likely to report some college education (61.7% vs. 30.0%), family income >$60,000 (43.4% vs. 11.8%), having full-time jobs (64.2% vs. 55.3%), and having a monogamous relationship (67.1% vs. 33.4%). Almost one-half (47.9%) of IUD users and approximately one-third (33.1%) of injectable users reported that the highest education level of their mothers (or mother figures) was some college or more. In addition, IUD users were more likely than injectable users to report being covered by private health insurance (59.0% vs. 37.9%) and less likely to be covered by Medicaid (15.5% vs. 33.1%). Predictors of Contraceptive Method Use After controlling for other potential predictors of contraceptive method use, compared with women using IUDs, injectable users were more likely to be non-hispanic African American (OR, 3.5; Fertility and Sterility â 1139

3 TABLE 1 Descriptive characteristics of women who used any method of reversible contraception. Contraceptive method a Characteristics IUD Injectables Pills and patches Barrier Other Unweighted n (weighted %) 246 (8.7) b 224 (5.2) 1,228 (43.4) 914 (28.6) 393 (14.1) Age, y Race and ethnicity c,d Non-Hispanic white Non-Hispanic African American Hispanic Others Education d Less than high school High school Some college Bachelor s degree or higher Marital status d Married Widowed, divorced, or separated Never married Employment d Never worked Worked, but not in the last 12 mo Full-time in the last 12 mo Part-time in the last 12 mo Annual family income d <$10, $10,000 $20, $20,000 $35, $35,000 $60, R$60, Place of birth d Born in United States Foreign born Living arrangements e Own Rent Highest education level of respondent s mother <High school High school Some college RBachelor s degree Mother s age at first birth, y e No children (respondent was adopted or a step child) < R No. of sex partners in the last 12 mo d R Xu et al. Users of intrauterine devices Vol. 96, No. 5, November 2011

4 TABLE 1 Continued. Contraceptive method a Characteristics IUD Injectables Pills and patches Barrier Other No. of live births d Never pregnant , with pregnancy R Number of mo without health insurance coverage in the last 12 mo d Type of health insurance coverage d No insurance coverage Private insurance plan only Medicaid (ever mentioned) Other public plans (ever mentioned) Current religious affiliation No religion Catholic Protestant Other Note: Categorized by method effectiveness, NSFG. Weighted percentage are reported in table. a Injectables only; pills and patches include contraceptive pills and patches; barrier methods (condom; diaphragm; female condom; vaginal pouch; foam, jelly, or cream; cervical cap; inserted suppository; and sponge); and other methods include withdrawal, pulling out, rhythm or safe period by calendar, planning, morning after pills or emergency contraception, ring, and others. The summation of percentages might be >1 because of rounding error. b The prevalence of IUD use in this table is >5.5%, which was widely cited in Mosher and Jones (10), because of the difference in the exclusion criteria. When Mosher and Jones (10) limited their sample to women aged 15 to 44 years who have ever had sexual intercourse and who had ever used the specified contraceptive method (Table 1), the prevalence of IUD increased to 7.4%, which is very close to our estimates. c P value is based on c 2 test of the distribution of all categories of the variable. d P<0.01. e P< % CI, ); to be widowed, divorced, or separated (OR, 3.3; 95% CI, ), to be never married (OR, 2.3; 95% CI, ), and to have no live births (OR, 34.2; 95% CI, ) (Table 2). In contrast, users of injectables were less likely to have a mother with the highest education level of college degree or higher (OR, 0.2; 95% CI, ). Compared with women using IUDs, users of pills and patches were also more likely to be widowed, divorced, or separated (OR, 2.4; 95% CI, ) and to have no live births (OR, 68.5; 95% CI, ). However, they were less likely to have 2 live births (OR, 0.4; 95% CI, ). Barrier method users and IUD users were comparable in terms of marital status and maternal background. However, barrier method users were more likely to be other than white, African American, or Hispanic (OR, 3.4; 95% CI, ), to have R4 sexual partners in the last 12 months (OR, 18.3; 95% CI, ), and to have no live births (OR, 49.3; 95% CI, ). Users of other reversible contraceptive methods and IUD users had similar sociodemographic characteristics but differed with respect to reproductive behaviors. Other contraceptive users were more likely to have R4 sexual partners in the last 12 months (OR, 4.4; 95% CI, ) and to have no live births (OR, 35.3; 95% CI, ), whereas they were less likely to have 2 live births (OR, 0.4; 95% CI, ) and to have a mother with the highest education level of college degree or higher (OR, 0.4; 95% CI, ). Reasons for Choosing the IUD The distribution of reversible-method contraceptive use among the respondents from the Guttmacher Institute survey was similar to that among those from the 2006 to 2008 NSFG (estimates not shown). Women using IUDs, hormonal contraception, or condoms were much more likely to report that preventing pregnancy was very important as a reason for their method choice than were women using other methods (mainly natural family planning and withdrawal) (86.4% vs. 36.9%). The following discussion is restricted to the first 3 groups of users, most of whom reported that preventing pregnancy was a very important reason for choosing the method. nd hormonal users listed many of the same reasons as very important for method choice: prevents pregnancy, does not interrupt sex, and provider s recommendation. A significantly greater proportion of women using IUDs (31.6%) than those using hormonal methods (17.0%) chose less expensive as a very important reason for use; the proportion of condom users considering cost to be very important (28.7%) was similar to that of IUD users (Table 3). Relative to users of hormonal methods, a significantly greater proportion of IUD users considered does not interrupt sex (70.5% vs. 47.9%) and partner does not know (10.0% vs. 3.5%) as very important reasons for their contraception choices; these questions were not asked of condom users. The only variable that significantly distinguished nd condom users was the importance of provider recommendation (60.0% and 23.1%, respectively). Fertility and Sterility â 1141

5 TABLE 2 Predictors for contraceptive method use: multinomial logistic regression estimates. Injectables vs. Pills and patches vs. Barrier vs. Other vs. Race and ethnicity Non-Hispanic white 1.0 ( ) 1.0 ( ) 1.0 ( ) 1.0 ( ) Non-Hispanic African American 3.5 b ( ) 1.0 ( ) 1.7 ( ) 1.1 ( ) Hispanic 1.3 ( ) 0.6 ( ) 0.9 ( ) 0.7 ( ) Others 1.0 ( ) 0.9 ( ) 3.4 b ( ) 2.4 ( ) Marital status Married 1.0 ( ) 1.0 ( ) 1.0 ( ) 1.0 ( ) Widowed, divorced, or separated 3.3 b ( ) 2.4 b ( ) 1.1 ( ) 1.3 ( ) Never married 2.3 c ( ) 1.0 ( ) 0.8 ( ) 0.9 ( ) No. of sex partners in the last 12 mo ( ) 2.4 ( ) 0.3 ( ) 0.6 ( ) ( ) 1.0 ( ) 1.0 ( ) 1.0 ( ) ( ) 0.6 ( ) 1.5 ( ) 0.9 ( ) R4 3.1 ( ) 2.9 ( ) 18.3 b ( ) 4.4 c ( ) No. of live births b ( ) 68.5 b ( ) 49.3 b ( ) 35.3 b ( ) ( ) 1.0 ( ) 1.0 ( ) 1.0 ( ) ( ) 0.4 b ( ) 0.6 ( ) 0.4 c ( ) R3 1.6 ( ) 0.7 ( ) 0.9 ( ) 1.4 ( ) Living arrangements Own 1.0 ( ) 1.0 ( ) 1.0 ( ) 1.0 ( ) Rent 0.6 ( ) 0.6 c ( ) 0.8 ( ) 0.7 ( ) Highest education level of respondent s mother <High school 1.0 ( ) 1.0 ( ) 1.0 ( ) 1.0 ( ) High school 0.8 ( ) 1.4 ( ) 1.4 ( ) 1.0 ( ) Some college 0.5 ( ) 0.9 ( ) 0.7 ( ) 0.6 ( ) RCollege graduate 0.2 b ( ) 0.6 ( ) 0.5 ( ) 0.4 c ( ) Mother s age at first birth No children (respondent was adopted or 6.6 ( ) 4.8 ( ) 3.5 ( ) 0.8 ( ) a step child) % ( ) 0.6 ( ) 0.8 ( ) 0.8 ( ) > ( ) 1.0 ( ) 1.0 ( ) 1.0 ( ) Note: NSFG. Adjusted ORs are reported in the table with 95% CI reported in parentheses. a IUD users are the common comparison group for users of all other contraceptive methods in the multinomial logistic regression analysis. b P<.01. c P<.05. Among all users of reversible contraception methods, women using IUDs reported the highest proportion of complete satisfaction (82.3% vs. 74.7% among hormonal users, 45.9% among condom users, and 50.0% among others; estimates not shown). None of the current IUD users reported dissatisfaction with this contraceptive method. The differences between IUD users and condom users or other nonhormonal method users were statistically significant. DISCUSSION Our findings demonstrated that IUD use in the mid-2000s was positively associated with parity. Specifically, the IUD was seldom used among nulliparous women. This may reflect the influence of older practice guidelines and package labeling, an historical view still held by many providers (17 19). The US Food and Drug Administration in 2005 no longer recommended the copper T380A IUD only for multiparous women. Another reason may be providers concern about insertion difficulties and pain experienced by nulliparous women during the insertion procedure (8, 20 24). Women with highly educated mothers were more likely to use IUDs relative to injectables, both of which are long-acting reversible contraceptives that require little maintenance and might be considered close substitutes. Our estimates also show that the share of IUD users among total users of long-acting reversible contraceptives increased considerably between the latest 2 waves of the NSFG, from 22% in the 2002 NSFG to 52% in the 2006 to 2008 NSFG (estimates not shown). The concentration of the increase in IUD use among relatively affluent women may reflect a tendency for more affluent people to be the first to take advantage of new health technologies (eg, drugs, screening tests for cancer) (25 28). The 2006 to 2008 NSFG data indicate that IUD use was less common among women who were widowed, divorced, or separated and among those who had R4 sexual partners in the 12 months preceding the date of the interview. These associations may have been partly due to providers counseling against IUDs among women judged to be at higher risk for sexually transmitted infections. Many providers believe that IUD use is associated with increased risk of pelvic inflammatory disease, though recent studies and 1142 Xu et al. Users of intrauterine devices Vol. 96, No. 5, November 2011

6 TABLE 3 Reasons for choosing current contraceptive method Guttmacher national telephone survey Current contraceptive method used IUD Hormonal Condoms Other Unweighted n (weighted %) 101 (4.9) 807 (50.7) 528 (32.3) 219 (12.1) Prevents pregnancy a Very important b Less expensive Very important b Provider recommended method Very important b 7.1 b Does not interrupt sex Very important b Partner does not know Very important b a Additional reasons exist on the questionnaire that were not posed for IUD users, such as prevent STDs [sexually transmitted diseases] or can be used when needed. The summation of percentages might be greater than 1 because of rounding error. b P<.05. literature review have shown that the risk of pelvic inflammatory disease and infertility among IUD users was quite low (15, 29, 30). The most frequently reported reasons for choosing either IUDs or hormonal methods in the 2004 Guttmacher Institute survey were the method s ability to prevent pregnancy, the method s ability to not interrupt sex, and provider s recommendation. The cost of the contraceptive device and personal privacy were also more likely to be considered by IUD users. IUD was well perceived among most users women who currently used IUDs reported the highest level of satisfaction among all users of reversible contraceptive methods, although not significantly higher than users of hormonal methods. Several limitations should be considered. First, all surveys are subject to recall bias when respondents are asked to recall past behaviors and social desirability bias regarding potentially stigmatizing behaviors. The retrospective design of the 2006 to 2008 NSFG raises issues of recall bias, and information was not collected on the timing of IUD insertions. Consequently, some information on socioeconomic, family background, and reproductive characteristics might not relate to the time period when the women underwent the IUD insertion. We do not have information to determine whether immigrants had the IUD insertion in the United States or in another country. Among foreign-born IUD users in the Guttmacher Institute survey, half had been in the United States for R10 years. It is unlikely that they obtained their IUD before immigration (although they may have obtained it during a return visit to their native country). Findings from the 2006 to 2008 NSFG show that recent IUD users differed from users of other reversible contraceptive methods. The use of the IUD was highest among parous women in monogamous relationships, a group that physicians have long considered to be the best candidates for IUD use. 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