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Effective Birth Control Use among Women at Risk for Unintended Pregnancy in Los Angeles, California

  • Author Footnotes
    † Present address: UC Irvine, Department of Medicine, 101 The City Drive South, City Tower, Suite 400, Orange, CA 92868-3217.
    Tanya M. Phares
    Correspondence
    Correspondence to: Tanya M. Phares, DO, MPH, Communicable Disease Control & Prevention, Los Angeles County Department of Public Health, 313 N. Figueroa Street, Rm 227, Los Angeles, CA 90012.
    Footnotes
    † Present address: UC Irvine, Department of Medicine, 101 The City Drive South, City Tower, Suite 400, Orange, CA 92868-3217.
    Affiliations
    Communicable Disease Control & Prevention, Los Angeles County Department of Public Health, 313 N. Figueroa Street, Rm 227, Los Angeles, California 90012
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  • Yan Cui
    Affiliations
    Office of Health Assessment and Epidemiology, Los Angeles County Department of Public Health, 313 N. Figueroa Street, Rm 127, Los Angeles, California 90012
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  • Susie Baldwin
    Affiliations
    Office of Health Assessment and Epidemiology, Los Angeles County Department of Public Health, 313 N. Figueroa Street, Rm 127, Los Angeles, California 90012
    Search for articles by this author
  • Author Footnotes
    † Present address: UC Irvine, Department of Medicine, 101 The City Drive South, City Tower, Suite 400, Orange, CA 92868-3217.

      Abstract

      Context

      Identifying sociodemographic and health-related risk factors associated with more effective versus less effective birth control use can help to identify barriers to effective birth control use and decrease risk for unintended pregnancy.

      Methods

      Data used were from the 2007 Los Angeles County Health Survey. More effective birth control use was assessed among women ages 18 to 49, who were at risk for unintended pregnancy, residing in Los Angeles County. The study population consisted of 849 women. Multivariate associations of more effective birth control use with sociodemographic and health factors were assessed in logistic regression models. All analyses used weighted data.

      Results

      Women who used a more effective birth control method at last act of coitus were less likely to be Black (odds ratio [OR], 0.33) or Asian/Pacific Islander (OR, 0.49), have less than a high school education (OR, 0.33), be a smoker (OR, 0.52), and have public insurance (OR, 0.47) than women using a less effective birth control method. They were more likely to have received a pap test (OR, 2.66), describe their health as fair or poor (OR, 2.39), and have a household income of 200% to 299% of the federal poverty level (OR, 2.25) than women using a less effective birth control method.

      Conclusions

      Sociodemographic factors, some of which underlie cultural diversity, predict the use of more effective birth control methods and should be considered when providing family planning services and preconception health counseling to unique populations.

      Introduction

      Decreasing unintended pregnancy can result in healthier women and babies (
      • Afable-Munsuz A.
      • Braveman P.
      Pregnancy intention and preterm birth: differential associations among a diverse population of women.
      ;
      • Sharma R.
      • Synkewecz C.
      • Raggio T.
      • Mattison D.R.
      Intermediate variables as determinants of adverse pregnancy outcome in high-risk inner-city populations.
      ;
      • Xaverius P.
      • Tenkku L.
      • Salas J.
      Differences between women at higher and lower risk for an unintended pregnancy.
      ). Unintended pregnancy is associated with detrimental behaviors in pregnancy, such as smoking and alcohol use, and poor perinatal health outcomes, including preterm delivery and low birth weight (
      • Afable-Munsuz A.
      • Braveman P.
      Pregnancy intention and preterm birth: differential associations among a diverse population of women.
      ;
      • Hellerstedt W.L.
      • Pirie P.L.
      • Lanso H.A.
      • Curry S.J.
      • McBride C.M.
      • Grothaus L.C.
      • et al.
      Differences in preconceptional and prenatal behaviors in women with intended and unintended pregnancies.
      ;
      • Sharma R.
      • Synkewecz C.
      • Raggio T.
      • Mattison D.R.
      Intermediate variables as determinants of adverse pregnancy outcome in high-risk inner-city populations.
      ). However, unintended pregnancy continues to occur at a high rate in the United States, where nearly half of all pregnancies are unintended (
      • Finer L.
      Disparities in rates of unintended pregnancy in the United States, 1994 and 2001.
      ;
      • Finer L.B.
      • Zolna M.R.
      Unintended pregnancy in the United States: Incidence and disparities, 2006.
      ;
      • Henshaw S.K.
      Unintended pregnancy in the United States.
      ). Of these unintended pregnancies, 43% ended in abortion in 2006 (
      • Finer L.B.
      • Zolna M.R.
      Unintended pregnancy in the United States: Incidence and disparities, 2006.
      ). Higher rates of unintended pregnancy occur among subgroups of women including low-income women, Black and Hispanic women, and younger women. The

      Healthy People 2010. (n.d.). Retrieved January 12, 2010, from http://www.healthypeople.gov.

      national health objective for family planning aimed to increase the proportion of intended pregnancies to 70%. This objective was not reached, and remains a national health objective for 2020 (

      Healthy People 2020. (n.d.). Retrieved January 12, 2010, from http://www.healthpeople.gov/hp2020/default.asp.

      ).
      Rates of unintended pregnancy in the United States remain high and continue to increase (
      • Finer L.B.
      • Zolna M.R.
      Unintended pregnancy in the United States: Incidence and disparities, 2006.
      ), despite widespread contraceptive use among sexually active heterosexual women (
      • Mosher W.D.
      • Martinez G.M.
      • Chandra A.
      • Abma J.C.
      • Wilson S.J.
      Use of contraception and use of family planning services in the United States, 1982-2002.
      ). Among women at risk for unintended pregnancy, 89% reported that they used contraception (
      • Mosher W.D.
      • Jones J.
      Use of contraception in the United States: 1982–2008.
      ). However, contraceptives are often used inconsistently or less effectively and the risk of failure varies by socioeconomic characteristics and type of method used (
      • Fu H.
      • Darroch J.E.
      • Haas T.
      • Ranjt N.
      Contraceptive failure rates: New estimates from the 1995 National Survey of Family Growth.
      ;
      • Kost K.
      • Singh S.
      • Vaughan B.
      • Trussel J.
      • Bankole A.
      Estimates of contraceptive failure from the 2002 National Survey of Family Growth.
      ). The highest method failure rates for typical use occur with periodic abstinence, withdrawal, spermicides, or the sponge when used by parous women (
      • Trussell J.
      Contraceptive Efficacy.
      ,
      • Trussell J.
      Contraceptive failure rates in the United States.
      ). For all methods, failure rates are highest among women who are low income, younger than 30, unmarried, and of Black or Hispanic ethnicity (
      • Fu H.
      • Darroch J.E.
      • Haas T.
      • Ranjt N.
      Contraceptive failure rates: New estimates from the 1995 National Survey of Family Growth.
      ). In 2001, 48% of unintended pregnancies occurred during a month when contraceptives were used (
      • Finer L.
      Disparities in rates of unintended pregnancy in the United States, 1994 and 2001.
      ). Moreover, higher rates of contraceptive risk taking are reported among women with incorrect fertility knowledge, as well as those with previous births and younger, Black or Hispanic women (
      • Radecki S.
      • Beckman L.
      Contraceptive risk-taking in a medically underserved, low-income population.
      ). It follows that identifying those at greatest risk for contraceptive failure, misuse, or nonuse is essential in decreasing unintended pregnancy.
      The American College of Obstetrics (ACOG) and the American Academy of Pediatrics (AAP) have recommended that preconception care incorporate screening and intervention to address a wide range of key maternal health issues, including (but not limited to) nutrition and folic acid intake, substance use such as tobacco and alcohol, chronic medical conditions, and reproductive planning. For women who want to delay pregnancy to optimize their health before conception, pregnancy planning and prevention are essential components of preconception healthcare that may help to improve maternal and fetal health outcomes. However, few studies have examined the preconception health of women at risk for unintended pregnancy in relation to their birth control method (

      Johnson, K., Possner, S. F., Biermann, J., Cordero, J. F., Atrash, H. K., Parker, C. S., et al. (2006). Recommendations to improve preconception health and health care - United States. MMWR, CDC, CDC/ATSDR Preconception Care Work Group and the Select Panel on Preconception Care.

      ). Understanding which sociodemographic and health-related risk factors are associated with more effective versus less effective birth control use can help to identify women at greatest risk for unintended pregnancy and thus poor preconception health practices. This increased understanding would allow providers to explore the barriers women face to using a more effective birth control method.
      In this study, we compared women in Los Angeles County who used more effective birth control methods with those who used less effective methods, considering demographic characteristics and various health indicators. Los Angeles County has a diverse population, which can be useful in illustrating variations in contraceptive use, particularly given the broad access to contraceptive services available in California through both state and federal funding. Family PACT, a California Medicaid (n.d.) Section 1115 Waiver covers all FDA-approved contraceptive methods for individuals with incomes at or below 200% of the federal poverty level (FPL) with no other source of reproductive healthcare and who are otherwise ineligible for Medicaid services (). Family PACT has shown to be very successful in improving the use of effective birth control methods and decreasing births in California (
      • Foster D.G.
      • Klaisle C.M.
      • Blum M.
      • Bradsberry M.E.
      • Brindis C.D.
      • Stewart F.H.
      Expanded state-funded family planning services: Estimating pregnancies averted by the Family PACT Program in California, 1997-1998.
      ). In 2002, the program enabled 205,000 women to avoid unintended pregnancy (
      • Foster D.G.
      • Biggs M.A.
      • Amaral G.
      • Brindis C.
      • Navarro S.
      • Bradsberry M.
      • et al.
      Estimates of pregnancy averted through California's family planning waiver program in 2002.
      ). Consequently, the cost of Family PACT has been shown to more than offset the costs associated with unintended pregnancy (
      • Foster D.G.
      • Raine T.R.
      • Brindis C.
      • Rostovtseva D.P.
      • Darney P.D.
      Should providers give women advance provision of emergency contraceptive pills? A cost-effectiveness analysis.
      ). The $404 million spent on Family PACT in 2002 generated a net savings of $1.8 billion for the state within 5 years (
      • Amaral G.
      • Foster D.G.
      • Biggs M.A.
      • Jasik C.B.
      • Judd S.
      • Brindis C.D.
      Public savings from the prevention of unintended pregnancy: A cost analysis of family planning services in California.
      ). Within this context, the focus on women in Los Angeles County in this study brings a unique perspective to the correlation between contraceptive method effectiveness and access to health services. The relationship between accessing reproductive health services and more effective birth control use has important implications for clinicians and policymakers because of the possibility of providing better counseling or support for a woman's chosen method and therefore improving efficacy.

      Methodology

      Study Population

      We used data collected in the 2007 Los Angeles County Health Survey (LACHS) to assess more effective birth control use among women ages 18 to 49 residing in Los Angeles County. The LACHS is a periodic, population-based telephone survey that collects information on demographics, health status, health conditions, health behaviors, use of preventive health services, and access to healthcare among Los Angeles County residents. The 2007 survey is composed of two components: An adult survey, on which this study is based, and a child survey. Households were randomly selected using a random-digit-dial sampling methodology and one adult respondent was randomly selected from each household. Computer-assisted telephone interviews were conducted by Field Research Corporation (San Francisco, CA) from April 3, 2007, to December 29, 2007. The survey was administered in English, Spanish, Cantonese, Mandarin, Korean, and Vietnamese; 26% of interviews were conducted in a language other than English. The average length of the core adult survey was 28 minutes, and ranged from an average of 26 minutes in English to 32 minutes in the non-English languages. The subsample questions added an additional 2 to 3 minutes to the total. The overall response rate for the survey was 18%, calculated as the ratio of households interviewed from the entire number of eligible households. The cooperation rate, reflecting the percent of eligible households in which a respondent successfully completed the survey once telephone contact was achieved, was 40%.
      Overall, 83,665 total telephone numbers were dialed. Interviews were completed for 7,200 housed, noninstitutionalized adult respondents aged 18 years or older. A detailed description of the 2007 LACHS methodology is available online at http://publichealth.lacounty.gov/ha/hasurveyintro.htm.

      More Effective Birth Control Use

      Women under age 50 who had at least one male sex partner in the past 12 months were asked to report whether they used any birth control method the last time they had sex. Specifically, they were asked to report whether they or their partners 1) used a condom, 2) had tubal ligation, 3) had a vasectomy, 4) used birth control pills, a patch, or ring, 5) had an intrauterine device, 6) used the Depo-Provera shot, 7) used a diaphragm or cervical cap, 8) used foam, jelly, or sponge, 9) used the withdrawal method, 10) used the rhythm method, 11) used a contraceptive implant, or 12) used some other method. Using an annual typical use failure rate of 18 % as the cutoff point, we categorized birth control methods into more effective versus less effective birth control methods (
      • Trussell J.
      Contraceptive failure rates in the United States.
      ). More effective birth control methods included tubal ligation; vasectomy; oral contraceptive pills, patch or ring; intrauterine device; Depo-Provera shot; implant; diaphragms or cervical cap; or condoms. Less effective birth control methods included the rhythm method, withdrawal, foam, jelly, sponge, some other method, or not using any method.
      We restricted analyses to women ages 18 to 49 who were at risk for unintended pregnancy. Specifically, these women must have had at least one male sexual partner in the past year, an intact uterus, and must have reported that they were not pregnant, were not trying to get pregnant during the last year, and were not infertile or menopausal. A total of 862 women fell into this group. Excluding 13 women with unknown status of birth control use, 849 women formed the study group.

      Demographics and Other Exploratory Variables

      We assessed demographic characteristics in association with more effective birth control use. These demographic factors included: Age groups (18–24, 25–29, 30–39, 40–49), race (Latina, White, Black/African American, Asian/Pacific Islander), education (less than high school, high school or GED, some college or trade school, college, or post graduate degree), language used most at home (English, Spanish, other language), employment status (full time, part time, not employed), income as percent of the FPL, (0%–99%, 100%–199%, 200%–299%, ≥300%), insurance status (public, private, uninsured) and marital status (coupled vs. not). Both married women and those who were cohabitating were included as “coupled.”
      We also examined a broad array of health indicators based on important preconception health screening and intervention categories designated by the ACOG, AAP, and U.S. Centers for Disease Control and Prevention. Self-reported health indicators as defined in this paper include current smoking, alcohol consumption (heavy or binge drinker, moderate drinker, nondrinker), intake of the recommended five or more servings of fruits or vegetables per day, frequency of fast food intake (<1 per month, <1once per week but >1 per month, ≥1 times per week), meeting recommended weekly physical activity guidelines,
      To meet Physical Activity Guidelines, at least one of the following criteria must be fulfilled: 1) Vigorous activity = hard physical activity causing heavy sweating, large increases in breathing and heart rate for 20 minutes or more, 3 or more days per week; 2) Moderate activity = causing light sweating, slight increases in breathing and heart rate for 30 or more minutes, 5 or more days per week; 3) A combination of vigorous and moderate activity meeting the time criteria for 5 or more days per week. (

      Healthy People 2010. (n.d.). Retrieved January 12, 2010, from http://www.healthypeople.gov.

      ).
      body mass index (kg/m2) based on reported height and weight (obese ≥30, overweight 25.0–29.9, normal 18.5–24.9, underweight <18.5), perceived general health status (excellent/very good, good, fair/poor), number of poor mental health days during the previous month (0, 1–4, ≥5 days), undergoing HIV testing in the past 2 years, having received Pap screening per recommended guidelines, having a dental visit in the past year, having at least one of three chronic health conditions that could complicate a pregnancy, including diabetes, hypertension, and heart disease.
      We categorized race and ethnicity using a mutually exclusive hierarchical system, based on California Department of Finance methodology.
      In this classification system, Latino ethnicity takes precedence over race, and when respondents report biracial or multiethnic heritage, they are hierarchically categorized as Latina, Black, Asian, Pacific Islander, American Indian/Alaska Native, or White, in that order.
      Few participants were classified as American Indian/Native Alaskan, prohibiting reliable statistical analyses for this population. Approximately 20% of survey participants did not provide sufficient income information to be assigned to a specific category of income to FPL ratio. A Markov chain Monte-Carlo method was used to impute these missing values. We assigned 19 participants with missing data for age to one of the age group categories, using the hot deck imputation method. All other variables were subject to limited missing data and no imputation was performed. Body mass index categories of underweight and normal weight were condensed owing to the small sample size in the underweight category. In accordance with the American College of Obstetricians and Gynecologists and American Cancer Society recommendations at the time of the survey, appropriate intervals for screening for women with a uterus were defined as having a Pap smear within the past 12 months for women 18 to 29 years old and within the past 3 years for women 30 to 64 years old.

      Statistical Analysis

      Survey weights were developed to account for differences in the probability of selection of households and adults into the sample, to adjust for households without telephone service, and to align survey estimates to known geographic and demographic characteristics of the county population. All statistical analyses employed weighted data to account for design effects.
      We conducted descriptive analyses to assess study population characteristics and more effective birth control use among subgroups of women defined by various factors. We also conducted logistic regression to evaluate associations between more effective birth control use and exploratory variables mentioned. We calculated the odds ratios and corresponding confidence limits for health indicators with adjustment for demographic factors and insurance status. For tests of trend in the odds across successive levels of categorical variables, we assigned the categories their ordinal number and then fitted the resulting variable as a continuous variable in the models. We evaluated the statistical significance using the Wald test. All p-values were two-sided. All statistical analyses were performed in SAS 9.1 (SAS institute, Cary, NC).

      Results

      Study Population

      Characteristics of the study population can be found in Table 1, Table 2. The women studied ranged in age from 18 to 49 years. The majority were either Latina (41.2%) or White (35.6%). One third had a high school education or less and 45% reported household incomes below 200% of the FPL. Many were employed full time (46.6%), married or cohabitating (60.9%), and had private insurance (63.1%). Overall, the population studied was healthy, with 58.7% reporting excellent or very good health, and 87.4% being nonsmokers. Among this population, 59.4% met physical activity guidelines and 57.7% had normal body mass indexes.
      Table 1Demographic Characteristics of Study Population
      Variablesn
      Numbers may not add up to 849 due to missing data.
      Percent
      Percentages were adjusted for sampling weights.
      Age group (yrs)
       18–249716.4
       25–2912320.1
       30–3930534.1
       40–4932429.4
      Race/ethnicity
       Latina38841.2
       White26135.6
       Black/African American8811.5
       Asian/Pacific Islander9411.3
       American Indian and White/American Indian110.5
      Statistically unstable estimate.
      Education
       Less than high school13715.2
       High school14917.6
       Some college or trade school22525.8
       College or post graduate degree33541.4
      Income (% FPL)
       0–9918222.9
       100–19917621.6
       200–29911413.0
       ≥30037742.5
      Language used most at home
       English57071.1
       Spanish20721.8
       Other657.1
      Employment
       Full time39646.6
       Part time15418.5
       Not employed29534.9
      Relationship
       Coupled58460.9
       Not coupled26139.1
      Insurance
       Public13117.8
       Private54163.1
       No insurance16619.1
      Numbers may not add up to 849 due to missing data.
      Percentages were adjusted for sampling weights.
      Statistically unstable estimate.
      Table 2Health Indicators in the Study Population
      Variablesn
      Numbers may not add up to 849 owing to missing data.
      Percent
      Percentages were adjusted for sampling weights.
      Smoking
       Yes9312.6
       No75287.4
      Alcohol
       Heavy or binge drinker13618.3
       Moderate drinker33041.2
       Nondrinker37340.4
      ≥5 servings of fruits or vegetables a day
       Yes17320.6
       No65279.4
      Fast Food
       <1 time per month21925.8
       <1 time per week but >1 time per month28033.5
       ≥1 times per week34940.6
      Meets physical activity guidelines
       Yes48159.4
       No36440.6
      Body mass index
       Obese14418.1
       Overweight18224.2
       Normal/underweight42057.7
      General health
       Excellent/very good49458.4
       Good26731.7
       Fair/poor889.9
      Chronic medical conditions
       Yes11211.2
       No73488.8
      Poor mental health days in past month (d)
       053059.0
       1–415219.6
       ≥515421.4
      HIV test in past 2 years
       Yes35545.6
       No48254.4
      Received age-appropriate Pap smear
      Age-appropriate Pap screening was defined as having received screening within the past 12 months for women 18–29 years old and within the past 3 years for women 30–64 years old, based on American Cancer Society and American College of Obstetricians and Gynecologists guidelines.
       Yes70782.1
       No13617.9
      Dental visit in past 1 year
       Yes53661.4
       No31238.6
      Numbers may not add up to 849 owing to missing data.
      Percentages were adjusted for sampling weights.
      Age-appropriate Pap screening was defined as having received screening within the past 12 months for women 18–29 years old and within the past 3 years for women 30–64 years old, based on American Cancer Society and American College of Obstetricians and Gynecologists guidelines.

      Comparison with More Effective to Less Effective Birth Control Use

      Of the 849 women included in this study, 79.4% reported using a more effective birth control method (Table 3). The percentage of women who used more effective birth control, within specific demographic or health indicator categories, can be found in Table 3, Table 4, along with adjusted odds ratios comparing more effective birth control users with less effective birth control users. Adjustments were made to account for potential confounding by age, race, education, job status, FPL, relationship, language used most at home, and insurance.
      Table 3Associations Between More Effective Birth Control Use and Demographic Characteristics Among Women (18–49 Years Old) at Risk for Unintended Pregnancy
      VariablesMore Effective Birth Control Use
      Percent (and confidence limits) of women at risk for unintended pregnancy who used a more effective birth control method the last time they had sexual intercourse.
      Adjusted OR
      Mutually adjusted for all variables listed in the table.
      (95% CL)
      PercentCL
      Overall LA County79.4%75.9–82.9
      Age group (yrs)
       18–247766.7–87.31.0 (ref)
       25–2983.474.9–91.91.45 (0.66–3.18)
       30–3980.174.2–861.39 (0.71–2.71)
       40–4977.172–82.20.92 (0.46–1.83)
      Race/ethnicity
       White85.180–90.21.0 (ref)
       Latina78.573.2–83.70.72 (0.38–1.35)
       Black/African American67.854.2–81.30.33 (0.16–0.69)
       Asian/Pacific Islander78.169–87.30.49 (0.24–0.99)
      Education
       College or post graduate degree82.577.8–87.21.0 (ref)
       Some college or trade school7769.6–84.40.73 (0.42–1.26)
       High school8679.5–92.61.55 (0.71–3.38)
       Less than high school67.856.9–78.70.33 (0.14–0.78)
      p for trend = .10
      Language
       English80.476.1–84.61.0 (ref)
       Spanish75.768.7–82.80.67 (0.31–1.46)
       Other80.868.4–93.11.62 (0.62–4.21)
      Employment
       Full time79.274.1–84.21.0 (ref)
       Part time82.776.3–89.11.23 (0.67–2.25)
       Not employed7871.4–84.51.15 (0.70–1.90)
      Income (%FPL)
       30080.375.6–85.11.0 (ref)
       200–29985.278.3–92.12.25 (1.08–4.68)
       100–19975.866.7–84.91.22 (0.59–2.51)
       0–9977.769.8–85.62.15 (0.94–4.94)
      p for trend = .12
      Relationship
       Coupled80.376.5–84.21.0 (ref)
       Not coupled77.771.1–84.40.91 (0.57–1.45)
      Insurance
       Private8278–86.11.0 (ref)
       Public68.157.1–79.10.47 (0.23–0.96)
       No insurance82.576.1–88.81.12 (0.54–2.32)
      Percent (and confidence limits) of women at risk for unintended pregnancy who used a more effective birth control method the last time they had sexual intercourse.
      Mutually adjusted for all variables listed in the table.
      Table 4Associations Between More Effective Birth Control Use and Selected Health Indicators Among Women (18–49 Years Old) at Risk for Unintended Pregnancy
      VariablesMore Effective Birth Control Use
      Percent (and confidence limits) of women at risk for unintended pregnancy who used a more effective birth control method the last time they had sexual intercourse.
      Adjusted OR
      Adjusted for age group, race/ethnicity, education, employment status, household income, marital status, and insurance status.
      (95% CL)
      PercentCL
      Smoking
       No81.377.9–84.61.0 (ref)
       Yes67.854.2–81.40.52 (0.28–0.95)
      Alcohol
       Nondrinker79.774.6–84.81.0 (ref)
       Moderate drinker81.676.4–86.91.02 (0.58–1.79)
       Heavy or binge drinker73.863.9–83.60.61 (0.33–1.20)
      p for trend = .17
      ≥5 Servings of fruits or vegetables a day
       No78.574.4–82.61.0 (ref)
       Yes83.176.6–89.71.32 (0.75–2.32)
      Fast food
       <1 time per month76.870–83.71.0 (ref)
       <1 time per week but >1 time per month80.173.8–86.41.29 (0.74–2.26)
       ≥1 times per week80.775.4–85.91.47 (0.89–2.43)
      p for trend = .15
      Meets physical activity guidelines
       No78.473.4–83.41.0 (ref)
       Yes80.175.2–84.91.07 (0.68–1.68)
      Body mass index
       Normal79.975.1–84.61.0 (ref)
       Obese72.562.3–82.61.05 (0.56–1.96)
       Overweight82.475.4–89.51.43 (0.78–2.65)
      General health
       Excellent/very good79.475–83.91.0 (ref)
       Good78.671.9–85.31.30 (0.78–2.14)
       Fair/poor81.671.7–91.52.39 (1.10–5.21)
      p for trend = .040
      Chronic medical conditions
       No79.675.8–83.41.0 (ref)
       Yes77.969.5–86.31.00 (0.54–1.86)
      Poor mental health days
       078.974.4–83.41.0 (ref)
       1–481.874.6–891.39 (0.77–2.48)
       ≥578.970.3–87.50.97 (0.56–1.70)
      p for trend = .91
      HIV test in past 2 years
       No80.576.4–84.61.0 (ref)
       Yes78.272.3–84.11.13 (0.70–1.84)
      Received age-appropriate Pap smear
      Age appropriate Pap screening was defined as having received screening within the past 12 months for women 18–29 years old and within the past 3 years for women 30–64 years old, based on American Cancer Society and American College of Obstetricians and Gynecologists guidelines, current at the time of the survey.
       No67.757.5–77.81.0 (ref)
       Yes81.978.4–85.52.66 (1.55–4.55)
      Dental visit in past 1 year
       No78.172.2–83.91.0 (ref)
       Yes80.275.8–84.51.03 (0.65–1.65)
      Percent (and confidence limits) of women at risk for unintended pregnancy who used a more effective birth control method the last time they had sexual intercourse.
      Adjusted for age group, race/ethnicity, education, employment status, household income, marital status, and insurance status.
      Age appropriate Pap screening was defined as having received screening within the past 12 months for women 18–29 years old and within the past 3 years for women 30–64 years old, based on American Cancer Society and American College of Obstetricians and Gynecologists guidelines, current at the time of the survey.
      Several sociodemographic characteristics were significantly associated with more effective birth control use. Black and Asian/Pacific Islander women were much less likely to have used a more effective birth control method than were White women (OR, 0.33 and 0.49, respectively), and women with less than a high school education were less likely to use more effective birth control, compared with women with a college or postgraduate degree (OR, 0.33). Women with household incomes 200% to 299% of the FPL were 2.25 times more likely to be more effective birth control users than women with incomes 300% or above the FPL. Although the majority of women with public insurance reported using a more effective birth control method, women with public insurance were significantly less likely than those with private insurance to use more effective birth control (OR, 0.47).
      Women who smoke were significantly less likely to be more effective birth control users (OR, 0.52) than were nonsmokers (Table 4). Women who reported their general health as fair or poor were 2.39 times more likely to use more effective birth control methods when compared with women who reported their general health as excellent or very good. There was also a significant trend showing an inverse relationship between general health status and more effective birth control. Women who had received an age-appropriate Pap test were more than twice as likely to use more effective birth control than those who had not had a recent Pap test (OR, 2.66).

      Discussion

      The majority of women in Los Angeles County used a more effective birth control method. Black and Asian/Pacific Islander women were less likely to use more effective birth control methods than White women, which may be due to differing cultural factors that influence their choice of birth control, as well as disparities in access to care and differential treatment in the provision of family planning services (
      • Borrero S.
      • Schwartz E.B.
      • Creinin M.
      • Ibrahim S.
      The impact of race and ethnicity on receipt of family planning services in the United States.
      ;
      • Thorburn S.
      Attitudes toward contraceptive methods among African-American men and women: Similarities and differences.
      ;
      • Thorburn S.
      • Bogart L.
      Conspiracy beliefs about birth control: barriers to pregnancy prevention among African Americans of reproductive age.
      ). Most of the birth control methods in the more effective category require a prescription or other healthcare encounter. Therefore, women who are not comfortable accessing care or do not have a good rapport with a healthcare provider may be less likely to use more effective methods (
      • Frost J.
      • Singh S.
      • Finer L.
      Factors associated with contraceptive use and nonuse.
      ;
      • Lee C.
      • Ayers S.
      • Kronenfeld J.
      The association between perceived provider discrimination, healthcare utilization and health status in racial and ethnic minorities.
      ).
      Women with the lowest level of education, as seen here, were least likely to use more effective birth control. Low educational attainment may influence a woman's ability to understand birth control options and instructions, and may negatively affect communications with a medical provider (
      • El-Ibiary S.
      • Youmans S.
      Health literacy and contraception: a readability evaluation of contraceptive instructions for condoms, spermicides and emergency contraception in the USA.
      ;
      • Ishikawa H.
      • Yano E.
      • Fujimori S.
      • Kinoshita M.
      • Yamanouchi T.
      • Yoshikawa M.
      • et al.
      Patient health literacy and patient–physician information exchange during a visit.
      ;
      • Rutherford J.
      • Taylor A.
      • Holman R.
      • MacDonald J.
      • Jarrett D.
      • Bigrigg A.
      Low literacy: A hidden problem in family planning clinics.
      ). Previous research has shown that women who do not understand written instructions for oral contraceptives were more likely to miss pills and have side effects, resulting in dissatisfaction with their birth control method as well as their provider (
      • Rosenberg M.
      • Waugh M.
      • Burnhill M.
      Compliance, counseling and satisfaction with oral contraceptives: A prospective evaluation.
      ).
      A recent study using national data found that women who are at high risk for an unintended pregnancy (i.e., not using birth control) were more likely to be of lower socioeconomic status than women at low risk for unintended pregnancy (
      • Xaverius P.
      • Tenkku L.
      • Salas J.
      Differences between women at higher and lower risk for an unintended pregnancy.
      ). Our results indicate that middle-income women (200%–299% FPL) were more likely than higher income women to use a more effective birth control method, although low-income women did not differ significantly from high-income women. Middle income corresponds with an annual household income of $32,158 to $48,076 for a family of three, at the time of survey interviewing (). The potential financial burden of an unintended pregnancy may have a greater influence on efforts to plan childbearing among middle-income women, than women of higher income. Previous research has described ambivalence toward child-bearing and skepticism about the ability to plan pregnancies among low-income women (
      • Chetkovich C.
      • Mauldon J.
      • Brindis C.
      • Guendelman S.
      Informed policy making for the prevention of unwanted pregnancy: understanding low-income women's experiences with family planning.
      ). However, more research is needed to explore the perspectives of women in middle- and high-income groups to better understand the role of income in pregnancy planning. Given that alcohol consumption is greater among high-income women with unintended pregnancies than women of lower incomes, it is essential that more effective contraception be used by women across all levels of income (
      • Tough S.
      • Tofflemire K.
      • Clarke M.
      • Newburn-Cook C.
      Do women change their drinking behaviors while trying to conceive? An opportunity for preconception counseling.
      ).
      We found that privately insured women were more likely to use more effective birth control methods than publicly insured women, which may reflect differences in health plan services, coverage, or delivery. In Los Angeles County, public insurance is provided through Medi-Cal managed care, allowing recipients to choose from different plans and providers (). Although all FDA-approved contraceptive methods are supposed to be covered by Medi-Cal, it is difficult to know whether equal access is provided under different plans. Further research is necessary to identify potential barriers within such managed care models. Our results also show that a greater percentage of women with no insurance use more effective birth control than those with public insurance. This contrasts with previous research using national data, which showed that women with Medicaid or private insurance were more likely than uninsured women to use prescription contraceptives (
      • Frost J.
      Public of private provders? U.S. women's use of reproductive health services.
      ;
      • Nearns J.
      Health insurance coverage and prescription contraceptive use among young women at risk for unintended pregnancy.
      ). More effective birth control use among uninsured women in Los Angeles may be explained by the existence of the Family PACT program in California. Although Family PACT covers a broad range of reproductive health services, because it does not cover other types of medical services women enrolled in the program often do not recognize or report it as a form of health insurance. Our findings on the association of having a Pap test with birth control use are consistent with previous research (
      • Xaverius P.
      • Tenkku L.
      • Salas J.
      Differences between women at higher and lower risk for an unintended pregnancy.
      ). The strong association of more effective birth control use with having had a recommended Pap test likely reflects that women receiving Pap tests have access to a healthcare provider who can provide methods that require a prescription or procedure. Additionally, there is a reasonably high rate of uninsured women who have received Pap tests (74%), further underscoring the potential effect of Family PACT. Women who undergo regular cervical cancer screening may also have more opportunities to receive comprehensive contraceptive counseling, which can inform their choice of a more effective birth control method. Although barriers to more effective birth control use are more complex than basic access to care, our results indicate that having access to reproductive healthcare, in general, positively influences the utilization of birth control. The relationship between accessing reproductive health services and more effective birth control use is important because of the opportunity to provide method counseling or support for a woman's chosen method.
      The inverse association seen between smoking and use of more effective birth control is alarming. Women who do not practice more effective birth control are at higher risk for unintended pregnancy, and risk exposing their fetus to the harmful effects of cigarette smoke before they are even aware that they are pregnant. Smoking during pregnancy can result in poor birth outcomes such as preterm birth or low birth weight infants, and poor childhood lung function (
      • Afable-Munsuz A.
      • Braveman P.
      Pregnancy intention and preterm birth: differential associations among a diverse population of women.
      ;
      • Prabhu N.
      • Smith N.
      • Campbell D.
      • Craig L.C.
      • Seaton A.
      • Helms P.J.
      • et al.
      First trimester maternal tobacco smoking habits and fetal growth.
      ;
      • Sharma R.
      • Synkewecz C.
      • Raggio T.
      • Mattison D.R.
      Intermediate variables as determinants of adverse pregnancy outcome in high-risk inner-city populations.
      ). More effective birth control use was not associated with chronic medical conditions evaluated in this study, namely, diabetes, hypertension, or heart disease. However, women who reported fair or poor general health may have other medical conditions not captured here. Women who reported worse general health status may be more likely to use more effective birth control because they are highly motivated to prevent pregnancy or have received contraceptive counseling from a regular healthcare provider. Choosing a birth control method for someone with a medical condition is a more complicated process, often done with the help of a physician skilled in managing the particular condition (
      • Vu K.
      • Zacur H.
      Contraception in women with intercurrent disease.
      ). This may reflect a different medical management approach to pregnancy prevention, which remains unique to women with medical conditions.
      Although beyond the scope of this paper, supporting women to improve the effectiveness of their chosen method could be more beneficial than changing methods for some women, particularly if they have a strong personal, religious, or cultural preference for a certain method.
      There are several limitations to this study. Because women were asked about the last birth control method that they used, the data do not reflect how long they used their current method or if they were using it effectively. Women who have changed methods frequently or switched from a less effective to more effective method cannot be accounted for in these data. Previous research has shown that 24% of reproductive age women had changed birth control methods within the past year (
      • Frost J.
      • Singh S.
      • Finer L.
      Factors associated with contraceptive use and nonuse.
      ). Gravidity and parity information were not collected in the survey, because it was a general public health survey. Women were also not asked questions regarding ambivalence toward using birth control or becoming pregnant. The degree to which ambivalence toward contraceptive use affects the results is unknown. The results may also be subject to recall bias, because self-reported survey data were used. Although Los Angeles County is large and incredibly diverse, the results are unique to Los Angeles, and should be used cautiously when making conclusions about other populations of women. Certain populations such as incarcerated or homeless women are not accounted for in this survey. Such women may be at high risk of unintended pregnancy and should be considered in future studies (
      • Gelberg L.
      • Lu M.C.
      • Leake B.D.
      • Andersen R.M.
      • Morgenstern H.
      • Nyamathi A.M.
      Homeless women: Who is really at risk for unintended pregnancy?.
      ). The survey's low response rate was another limitation, reflecting a decline in telephone survey response rates nationwide. Our survey response rate was comparable with that of the 2007 California Health Interview Survey for the Los Angeles region. Nevertheless, it has been demonstrated repeatedly that nonresponse may not introduce substantial biases into survey estimates (
      • Keeter S.
      • Kennedy C.
      • Dimock M.
      • Best J.
      • Graighill P.
      Gauging the impact of growing nonresponse on estimates from a national RDD telephone survey.
      ;
      • Keeter S.
      • Miller C.
      • Kohut A.
      • Groves R.M.
      • Presser S.
      Consequences of reducing nonresponse in a national telephone survey.
      ). Moreover, the unweighted LACHS sample closely reflected the population makeup of noninstitutionalized adults. Finally, it should be noted that the efficacy of contraceptive methods may evolve over time, as potentially demonstrated by Kost and colleagues (2008), who reported a drop in withdrawal failure from 28% to 18% over the course of 7 years. This result, however, was not significant because of the small sample size.
      Policymakers and clinicians alike can use these results to ensure that all women are receiving equal services, decrease barriers to contraceptive use and decrease system failures that may affect contraceptive efficacy. National preconception health goals call for every woman to develop a reproductive health plan (

      Johnson, K., Possner, S. F., Biermann, J., Cordero, J. F., Atrash, H. K., Parker, C. S., et al. (2006). Recommendations to improve preconception health and health care - United States. MMWR, CDC, CDC/ATSDR Preconception Care Work Group and the Select Panel on Preconception Care.

      ). To achieve such goals and improve use of more effective birth control methods, family planning providers should be sensitive to the cultural background and education level of the population served. Continued support is needed to provide women of low income with good access to family planning, through programs proven to be successful, such as Family PACT. Although many unintended pregnancies can be avoided by improved use of more effective contraceptive methods, it is also essential that women are educated on the importance of preconception health and the risk of behaviors such as smoking during pregnancy.

      References

        • Afable-Munsuz A.
        • Braveman P.
        Pregnancy intention and preterm birth: differential associations among a diverse population of women.
        Perspectives on Sexual and Reproductive Health. 2008; 40: 66-73
        • Amaral G.
        • Foster D.G.
        • Biggs M.A.
        • Jasik C.B.
        • Judd S.
        • Brindis C.D.
        Public savings from the prevention of unintended pregnancy: A cost analysis of family planning services in California.
        Health Services Research. 2007; 42: 1960-1980
        • Borrero S.
        • Schwartz E.B.
        • Creinin M.
        • Ibrahim S.
        The impact of race and ethnicity on receipt of family planning services in the United States.
        Journal of Women's Health. 2009; 18: 91-96
      1. California Family PACT. (n.d.). Retrieved June 8, 2010, from http://www.cdph.ca.gov/programs/FamilyPact/Pages/default.aspx.

      2. California Medicaid. (n.d.). Retrieved June 7, 2010, from http://www.dhcs.ca.gov/services/Pages/MedicalManagedCare.asph.

        • Chetkovich C.
        • Mauldon J.
        • Brindis C.
        • Guendelman S.
        Informed policy making for the prevention of unwanted pregnancy: understanding low-income women's experiences with family planning.
        Evaluation Review. 1999; 23: 527-552
        • El-Ibiary S.
        • Youmans S.
        Health literacy and contraception: a readability evaluation of contraceptive instructions for condoms, spermicides and emergency contraception in the USA.
        The European Journal of Contraception & Reproductive Health Care. 2007; 12: 58-62
        • Finer L.B.
        • Zolna M.R.
        Unintended pregnancy in the United States: Incidence and disparities, 2006.
        Contraception. 2011; 84: 478-485
        • Finer L.
        Disparities in rates of unintended pregnancy in the United States, 1994 and 2001.
        Perspectives on Sexual and Reproductive Health. 2006; 38: 90-96
        • Foster D.G.
        • Biggs M.A.
        • Amaral G.
        • Brindis C.
        • Navarro S.
        • Bradsberry M.
        • et al.
        Estimates of pregnancy averted through California's family planning waiver program in 2002.
        Perspectives on Sexual and Reproductive Health. 2006; 38: 126-131
        • Foster D.G.
        • Klaisle C.M.
        • Blum M.
        • Bradsberry M.E.
        • Brindis C.D.
        • Stewart F.H.
        Expanded state-funded family planning services: Estimating pregnancies averted by the Family PACT Program in California, 1997-1998.
        American Journal of Public Health. 2004; 94: 1341-1346
        • Foster D.G.
        • Raine T.R.
        • Brindis C.
        • Rostovtseva D.P.
        • Darney P.D.
        Should providers give women advance provision of emergency contraceptive pills? A cost-effectiveness analysis.
        Women's Health Issues. 2010; 20: 242-247
        • Frost J.
        Public of private provders? U.S. women's use of reproductive health services.
        Family Planning Perspectives. 2001; 33: 4-12
        • Frost J.
        • Singh S.
        • Finer L.
        Factors associated with contraceptive use and nonuse.
        Perspectives on Sexual and Reproductive Health. 2007; 39: 90-99
        • Fu H.
        • Darroch J.E.
        • Haas T.
        • Ranjt N.
        Contraceptive failure rates: New estimates from the 1995 National Survey of Family Growth.
        Family Planning Perspectives. 1999; 31: 56-63
        • Gelberg L.
        • Lu M.C.
        • Leake B.D.
        • Andersen R.M.
        • Morgenstern H.
        • Nyamathi A.M.
        Homeless women: Who is really at risk for unintended pregnancy?.
        Maternal and Child Health Journal. 2008; 12: 52-60
      3. Healthy People 2010. (n.d.). Retrieved January 12, 2010, from http://www.healthypeople.gov.

      4. Healthy People 2020. (n.d.). Retrieved January 12, 2010, from http://www.healthpeople.gov/hp2020/default.asp.

        • Hellerstedt W.L.
        • Pirie P.L.
        • Lanso H.A.
        • Curry S.J.
        • McBride C.M.
        • Grothaus L.C.
        • et al.
        Differences in preconceptional and prenatal behaviors in women with intended and unintended pregnancies.
        American Journal of Public Health. 1998; 88: 663-666
        • Henshaw S.K.
        Unintended pregnancy in the United States.
        Family Planning Perspectives. 1998; 30: 24-29
        • Ishikawa H.
        • Yano E.
        • Fujimori S.
        • Kinoshita M.
        • Yamanouchi T.
        • Yoshikawa M.
        • et al.
        Patient health literacy and patient–physician information exchange during a visit.
        Family Practice. 2009; 26: 517-523
      5. Johnson, K., Possner, S. F., Biermann, J., Cordero, J. F., Atrash, H. K., Parker, C. S., et al. (2006). Recommendations to improve preconception health and health care - United States. MMWR, CDC, CDC/ATSDR Preconception Care Work Group and the Select Panel on Preconception Care.

        • Keeter S.
        • Kennedy C.
        • Dimock M.
        • Best J.
        • Graighill P.
        Gauging the impact of growing nonresponse on estimates from a national RDD telephone survey.
        Public Opinion Quarterly. 2006; 70: 759-779
        • Keeter S.
        • Miller C.
        • Kohut A.
        • Groves R.M.
        • Presser S.
        Consequences of reducing nonresponse in a national telephone survey.
        Public Opinion Quarterly. 2000; 64: 125-148
        • Kost K.
        • Singh S.
        • Vaughan B.
        • Trussel J.
        • Bankole A.
        Estimates of contraceptive failure from the 2002 National Survey of Family Growth.
        Contraception. 2008; 77: 10-21
        • Lee C.
        • Ayers S.
        • Kronenfeld J.
        The association between perceived provider discrimination, healthcare utilization and health status in racial and ethnic minorities.
        Ethnicity & Disease. 2009; 19: 330-337
        • Mosher W.D.
        • Jones J.
        Use of contraception in the United States: 1982–2008.
        National Center for Health Statistics, Hyattsville, MD2010
        • Mosher W.D.
        • Martinez G.M.
        • Chandra A.
        • Abma J.C.
        • Wilson S.J.
        Use of contraception and use of family planning services in the United States, 1982-2002.
        Advance Data From Vital and Health Statistics. 2004; 350: 1-36
        • Nearns J.
        Health insurance coverage and prescription contraceptive use among young women at risk for unintended pregnancy.
        Contraception. 2009; 79: 105-110
        • Prabhu N.
        • Smith N.
        • Campbell D.
        • Craig L.C.
        • Seaton A.
        • Helms P.J.
        • et al.
        First trimester maternal tobacco smoking habits and fetal growth.
        Thorax. 2010; 65: 235-240
        • Radecki S.
        • Beckman L.
        Contraceptive risk-taking in a medically underserved, low-income population.
        Social Biology. 1993; 40: 248-259
        • Rosenberg M.
        • Waugh M.
        • Burnhill M.
        Compliance, counseling and satisfaction with oral contraceptives: A prospective evaluation.
        Family Planning Perspectives. 1998; 30: 89-92
        • Rutherford J.
        • Taylor A.
        • Holman R.
        • MacDonald J.
        • Jarrett D.
        • Bigrigg A.
        Low literacy: A hidden problem in family planning clinics.
        The Journal of Family Planning and Reproductive Health Care. 2006; 32: 235-240
        • Sharma R.
        • Synkewecz C.
        • Raggio T.
        • Mattison D.R.
        Intermediate variables as determinants of adverse pregnancy outcome in high-risk inner-city populations.
        Journal of the National Medical Association. 1994; 86: 857-860
        • Thorburn S.
        Attitudes toward contraceptive methods among African-American men and women: Similarities and differences.
        Women's Health Issues. 2007; 17: 29-36
        • Thorburn S.
        • Bogart L.
        Conspiracy beliefs about birth control: barriers to pregnancy prevention among African Americans of reproductive age.
        Health Education Behavior. 2005; 32: 474-487
        • Tough S.
        • Tofflemire K.
        • Clarke M.
        • Newburn-Cook C.
        Do women change their drinking behaviors while trying to conceive? An opportunity for preconception counseling.
        Clinical Medicine & Research. 2006; 4: 97-105
        • Trussell J.
        Contraceptive Efficacy.
        in: Hatcher R.A. Trussell J. Nelson A.L. Cates W. Stewart F.H. Kowal D. Contraceptive technology. 19th rev. ed. Ardent Media, New York2007
        • Trussell J.
        Contraceptive failure rates in the United States.
        Contraception. 2011; 83: 397-404
      6. U.S. Census Poverty Thresholds. (2006). Retrieved June 13, 2010, from http://www.census.gov/hhes/www/poverty/threshld/thresh06.html.

        • Vu K.
        • Zacur H.
        Contraception in women with intercurrent disease.
        Current Opinion in Obstetrics & Gynecology. 1994; 6: 547-551
        • Xaverius P.
        • Tenkku L.
        • Salas J.
        Differences between women at higher and lower risk for an unintended pregnancy.
        Women's Health Issues. 2009; 19: 306-312

      Biography

      Tanya Phares, DO, MPH, completed a preventive medicine residency with the California Department of Public Health, and is currently a resident at UC Irvine in internal medicine. Her interests include women's health and obstetric medicine.
      Yan Cui, MD, PhD, is an epidemiologist with the Office of Health Assessment and Epidemiology of the Los Angeles County Department of Public Health. Dr Cui specializes in cancer epidemiology and population survey methodology.
      Susie Baldwin, MD, MPH, FACPM, is a public health and preventive medicine specialist who serves as Health Assessment Unit Chief at the Los Angeles County Department of Public Health. Her interests include women's health and reproductive health.