A longitudinal study of adult pregnant Latinas attending obstetric clinics in Los Angeles was designed to examine the impact of IPV exposure on Latinas during the perinatal period. Prenatal interviews after the first trimester of pregnancy were followed by interviews at 3, 7, and 13 months post-partum. The recruitment sites were obstetric clinics at private, non-profit, healthcare organizations – a local HMO organization and a medical center - where more than 80% of the population was Latina. Latina patients who screened positive for IPV (IPV-exposed) were eligible for the study, as were pregnant Latinas who reported no previous exposure to IPV (non-IPV-exposed); the latter served as a comparison group. To promote retention, only women who reported that they planned to raise their children in Los Angeles County during the children's first year of life were eligible for study inclusion. The study protocol was approved by the Institutional Review Boards (IRB) of each recruitment site and the University of California, Los Angeles (UCLA).
All women attending obstetric clinics at the HMO and at the medical center between January 2003 and January 2004 were approached by research staff and informed about the study while waiting for routine appointments (n=1,728). Baseline interviews took place between April 2003 and March 2004. The first follow-up interviews were conducted between September 2003 and July 2004, the second follow-up interviews were conducted December 2003 and January 2005, and the third follow-up interviews were conducted between June 2004 and April 2005. These interviews were scheduled to take place initially when the women were at least three months pregnant but had not yet given birth with the three follow up interviews occurring at three, seven, and 13 months post-partum. At the HMO, the clinic staff would let each woman know that someone from a research study either would be approaching them when they were shown into an exam room at the time of appointment check in or the staff would direct the woman to a private room where researchers would be screening them prior to being shown into an exam room. At the private medical center, the research assistant flagged the patient's registration paperwork informing the front desk staff that the assistant would be approaching the patient and taking her aside to a private confidential space to introduce her to the study. The research assistant would introduce herself as a researcher working on a research study to understand the needs of pregnant Latina women and their babies to help enhance healthcare services provided to them. To avoid stigmatization, the study was not labeled as an IPV study but it was made clear that the study would inquire into sensitive issues, including IPV. Potential participants were asked if they could be screened to determine eligibility and if eligible, they were invited to participate. They were told that participation consisted of responding to five questionnaires (one during pregnancy and then up to four during their infant's first two years) and that the interviews would improve our understanding of the needs of pregnant Latina women and their infants in order to enhance healthcare services provided to them.
Of the original 1,728 potentially eligible women who were originally to be approached for the study, 140 refused to be screened while 44 women were either approached twice or were lost before they could be approached, leaving 1,544 who were screened. Of these, 682 screened eligible while 862 screened ineligible. Of these 682 eligible women, nine IPV positive women and 46 IPV negative women refused enrollment while 417 IPV negative women were turned away due to the quota of IPV negative women being filled leaving 92 IPV negative and 118 IPV positive women enrolled in the study. Thus, while there may have been some selection bias among the women who did not decline screening, the overwhelming majority of women agreed to be screened and selection effects should be small.
An interview was administered to study participants by trained bilingual Latina research associates. The questionnaire included validated questions, assessment scales and screening tools already available in both English and Spanish. Participants received $25 for each interview completed.
Demographic questions included age, birthplace (foreign/US- born) and language of interview. Total family income was divided by the federal poverty level for number of persons in the household to create the Poverty Index, in which higher scores indicate higher levels of income above the poverty threshold. Other sociodemographic variables collected included parity, employment status, partner status and educational attainment.
IPV status, the main independent variable, was ascertained using questions from the four-question Abuse Assessment Screen (AAS) (Perlin & Schooler, 1978
). Questions include lifetime adult physical and sexual abuse by an intimate partner. This assessment precludes the assessment of temporality and whether the abuse was by the woman's current intimate partner and/or father of the baby. We modified this measure to include psychological experiences of being made to feel fearful for their safety. Women with positive responses to any one of the items were classified as IPV-exposed.
Protective factors included mastery and social support. Mastery was measured with a five-item modified version of the Mastery Scale (Perlin & Schooler, 1978
), which measures sense of control over forces that influence one's life. Item scores range from five to 20, with higher scores indicating higher mastery. Social support was measured with a modified version of the Medical Outcomes Study Social Support Survey related to instrumental (e.g., receiving transportation assistance) and emotional support (e.g., having someone to talk to) from formal (agencies) and informal sources (friends, family) (Sherbourne & Stewart, 1999
). Scores range from nine to 45, with higher scores indicating higher social support.
Risk factors included avoidant coping style, stress, and non-IPV trauma history. Avoidant coping style was assessed with a subscale from the Medical Outcomes Study (Abbey, Abramos, & Caplan, 1985
) which included various “avoidant” coping strategies. Higher scores indicated poorer coping strategies. Stress level was measured with the Perceived Stress Scale (PSS-4) to assess perceived ability to handle “personal problems” and “important things in life,” with scores ranging from four to 20 in which higher scores indicated higher perceived stress (Cohen, Kamarck, & Mermelstein, 1983
). Trauma history was assessed with six items from the Trauma History Questionnaire (Green, 1996
) and six items from the Adverse Childhood Experiences Study Questionnaire (Felitti et al., 1998
). Non-IPV trauma history included past physical or verbal child abuse, witnessing of domestic violence, past experience of physical abuse that left marks (non-IPV,) sexual abuse (non-IPV,) or loss of parent before age 18.
Depression, the major outcome of interest, was measured by the Beck Depression Inventory Fast Screen (BDI-FS) for Medical Patients (Beck, Steer, & Brown, 2000
; Steer et al., 1991
). The BDI-FS has seven items rated for the past two weeks on a four point Likert scale. Consistent with the literature, a cut-off score of four or above indicated that a participant was depressed. The BDI-FS has sensitivity and specificity greater than 0.80 (Winter et al., 1999
). Total scores on the BDI-FS range from zero to 21, with higher scores suggestive of greater severity. Study protocols were used to assure participants' and their children's safety during the study.
The prevalence of depression among IPV-exposed women was compared with prevalence among non-IPV-exposed women at each of the four assessment periods: prenatal, 3, 7 and 13 months after birth. The cumulative frequency of depression (0, 1, 2, or 3-4), the prevalence of risk factors (avoidant coping style, perceived stress, non-IPV trauma, acculturation, and poverty,) and protective factors (social support and mastery) were compared among IPV-exposed and non-exposed mothers at each of the four time periods. A correlation matrix was used to evaluate potential multicollinearity among any of the predictors. Chi-square tests or t-tests were used to assess differences in all bivariate analyses for a given time point. The binomial exact test was used to calculate 95% confidence intervals for point estimates of depression. Marginal repeated measures mixed effects models examined the statistical significance of all independent predictors over time. After systematically testing each variable for statistical significance and using the literature as a basis for determining what variables should be included in the model, final multivariate repeated measures mixed effects models identified variables that were independently correlated with depression, as a continuous outcome over time. SAS Statistical Software, Version 9.1 was used for all analyses.
The study sample is composed of 210 women living in the greater Los Angeles metropolitan area of whom 44% (n=92) were IPV-exposed and 56% (n=118) were non-IPV-exposed at the baseline interview (). Compared to non-IPV-exposed participants, IPV-exposed participants were significantly more likely to be older and born in the U.S. (30.4% versus 18.6%). In addition, IPV-exposed women were significantly more likely to have higher parity, be employed full or part-time, unmarried and to have graduated from high school.
Demographic characteristics of study participants at study entry, by IPV Status (n=210)
Patterns of Prenatal and Post-natal Depression
Women in both groups experienced depression in the prenatal and post-natal periods (). While depression was highest in the prenatal period for both IPV-exposed (45.7%) and non-exposed women (24.6%), it was lowest three months after birth (28.0% and 7.3% respectively). Then, depression went up at seven months for both groups (to 42.7% of IPV-exposed and to12.4% of non-exposed women). Finally, at the 13 month time point, depression decreased among IPV-exposed women (39.8%) but increased among non-exposed women (17.5%). At each time point (prenatally, 3, 7, and 13 months after birth), significantly more IPV-exposed women scored at or over the cut-off for depression (p<.001 at each time point) compared to non-exposed women. Mean depression scores for IPV-exposed women at each time point were 3.5 (prenatally), 2.13 (3 months), 3.36 (7 months) and 2.97 (13 months) which were significantly higher than those of the non-IPV exposed women, i.e., 1.49 (prenatally), 0.67 (3 month), 0.97 (7 month) and 1.11 (13 month)(t-score=-3.58, -3.58, -4.84, and -3.74 respectively, p<.001 for each time point).
Proportion of Latina mothers with depression in prenatal and infancy periods, by IPV status.
Approximately 71% of IPV-exposed and 40% of non-IPV-exposed women met or exceeded the cut-off for depression at least once during the four assessment periods. Persistence of depression, as indicated by scores that exceeded the cut-off for depression at more than two of the four assessments, differed significantly by IPV status (.) Persistent depression was greater than five times more likely within the IPV-exposed group than within the non-IPV-exposed group (27.3% vs. 5.2%, p<.0001.) A significantly higher proportion of IPV-exposed women scored at or above the cut-off score for depression at two of the four assessments, with a greater than two-fold difference between the exposed and non-exposed groups (17.1% vs. 7.2%, p<.05.). Approximately, 29.5% of IPV-exposed mothers scored at or above the cut-off for depression only once during the perinatal period, compared to 21.7% of non-IPV-exposed mothers. However, this difference was not significant (p=0.28.)
Proportion of Mothers with Different Frequencies of Depression during Pregnancy and Infancy by IPV Status and 95% Confidence Limits
Protective and Risk Factors
Over the four time points, avoidant coping and perceived stress were higher in IPV-exposed subjects than in non-exposed participants across all time points (.) In contrast, mastery scores did not significantly differ during the prenatal period, but did significantly differ at the seven and 13 month post-natal assessment time points. Likewise, perceived social support was significantly higher in non-IPV-exposed mothers at the prenatal, three and seven month post-natal time points but not at the 13 month post-natal time point. IPV-positive participants scored lower on social support at each of the four time points when compared with non-IPV-exposed participants. Furthermore, IPV-exposed participants scored lower on mastery at all of the three post-natal time points, significantly higher on avoidant coping style at all four time points, and significantly higher on the perceived stress measure at all three post-natal time points.
Protective and risk factors of Latina mothers, by IPV status at each assessment
Impact of Protective and Risk Factors on Depression
The mixed model results shown in indicate that high scores on mastery and social support were negatively associated with depression over time. Avoidant coping style and perceived stress were positively associated with depression over time. In addition, history of non-IPV-related trauma was not significantly associated with perinatal depression or the language in which the interview was conducted.
Results of Multivariate Repeated Measures Mixed Model for maternal risk and protective factors associated with depression during pregnancy and throughout infancy