Social Support and Self-Esteem as Mediators Between Stress and Antepartum Depressive Symptoms in Rural Pregnant Women D. Elizabeth Jesse, Heejung Kim, Cynthia Herndon
Correspondence to D. Elizabeth Jesse E-mail: [email protected] D. Elizabeth Jesse Associate Professor East Carolina University College of Nursing 3160 Health Sciences Building Greenville, NC 27858 Associate Professor Brody School of Medicine Greenville, NC Heejung Kim School of Nursing University of Kansas Kansas City, Kansas Cynthia Herndon East Carolina University College of Nursing 3160 Health Sciences Building Greenville, NC 27858
Abstract: The purpose of this secondary analysis was to determine whether satisfaction with social support and self-esteem mediated the relationship between antepartum stress and depressive symptoms in women attending prenatal clinics in a rural Southeastern community (N ¼ 318). Path analysis with linear regression indicated that the relationship between antepartum stress and depressive symptoms was partially mediated by higher levels of the internal resources of satisfaction with social support and self-esteem. Self-esteem had a greater influence on the relationship between antepartum stress and depressive symptoms than did satisfaction with social support. These findings suggest further study to determine whether developing culturally tailored interventions that emphasize stress reduction activities in addition to enhancing self-esteem and increasing satisfaction with social support can decrease the burden of antepartum depressive symptoms in rural low-income women. ß 2014 Wiley Periodicals, Inc. Research in Nursing & Health, 2014, 37, 241–252 Accepted 1 April 2014 DOI: 10.1002/nur.21600 Published online 4 May 2014 in Wiley Online Library (wileyonlinelibrary.com).
Pregnancy is a life-changing event that can bring uplifting and positive emotions (Dipietro, Christensen, & Costigan, 2008); at the same time, the physical and emotional changes of approaching motherhood can feel stressful and overwhelming. Up to 51% of pregnant women experience antepartum depressive symptoms, defined as symptoms that do not fully meet the criteria for antepartum depression (American Psychiatric Association [APA], 2013). Among women experiencing depressive symptoms, 11% develop antepartum depression (Bennett, Einarson, Taddio, Koren, & Einarson, 2004; Gaynes et al., 2005), a major unipolar depression with 8–14 symptoms that persist for greater than 2 weeks (APA, 2013). In turn, both antepartum depressive symptoms and depression can lead to adverse infant birth outcomes and postpartum depression (Grigoriadis et al., 2013). In a national study, Witt et al. (2011) found that, compared to pregnant women with no mental health problems, those with poor mental health in pregnancy were over 11 times more likely to report poor mental health postpartum.
This can lead to poor maternal–infant attachment and compromised child development (Field, 2010; Hayes, Goodman, & Carlson, 2013). Women with untreated antepartum depressive symptoms are at twice the risk for preterm birth (Grote et al., 2010; Li, Liu, & Odouli, 2009) and even death by suicide (Palladino, Singh, Campbell, Flynn, & Gold, 2011). Untreated antepartum depressive symptoms disproportionately affect rural, minority and low-income women, who often have inadequate access and availability of health care during pregnancy and little or no health insurance (Bloom, Bullock, & Parson, 2012; Hauenstein & Peddada, 2007; Hauenstein et al., 2006; Hillemeier, Weisman, Chase, & Dyer, 2008; Jesse & Swanson, 2007; Price & Proctor, 2009). Rural women are highly vulnerable to antepartum stress as well as depressive symptoms, especially when a partner or family support system is absent or unsatisfying (Jesse & Swanson, 2007). Although there is a growing body of literature on the relationships among stress, satisfaction with social support, C
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and depressive symptoms in rural pregnant women (Bloom et al., 2012; Hauenstein & Peddada, 2007; Hauenstein et al., 2006; Hillemeier et al., 2008; Jesse & Swanson, 2007; Proctor & Price, 2009), few have used an empirically tested framework to investigate the role of self-esteem in antepartum depression (Jesse & Swanson, 2007), and to our knowledge, none have assessed whether relationships among these three variables could simultaneously affect antepartum depression. Understanding the potential mediator role of satisfaction with social support and self-esteem in the relationship between antepartum stress and depressive symptoms among rural pregnant women may be critical for developing intervention strategies as a part of comprehensive prenatal care. The purpose of this secondary analysis was to determine whether satisfaction with social support and level of self-esteem mediated the relationship between antepartum stress and depressive symptoms in rural pregnant women.
Relationships of Stress, Social Support, and Self-Esteem to Antepartum Depressive Symptoms Psychosocial stress is defined as an imbalance among daily hassles, emotional demands, and coping strategies (Kanner, Coyne, Schaefer, & Lazaus, 1981; Woods, Melville, Guo, Fan, & Gavin, 2010). Perceived life stress is the most commonly cited reason for women experiencing antepartum depressive symptoms (Lancaster et al., 2010; Woods et al., 2010). In Bloom et al.'s (2012) qualitative study (N ¼ 24), Caucasian pregnant women living in a Midwest rural area described high levels of stress caused by financial worries, lack of access to affordable housing, lack of transportation, and unemployment. Over half of these women reported feeling at risk for clinical depression during pregnancy. Jesse and Swanson (2007) found that rural pregnant women at risk for antepartum depression were almost four times more likely to experience negative stress than those at no risk for depression. However, this may be an underestimation, as pregnant women living in rural areas may not reveal their feelings of sadness and depression to professionals or to family, for fear of being labeled “crazy” or being reported to social services as unfit mothers (Jesse, Dolbier, & Blanchard, 2008). Lack of access to adequate mental health resources and transportation problems also prevent them from seeking medical treatment until late stages of a depressive episode, when symptoms are worse and effective intervention is more difficult (Bloom et al., 2012; Jesse et al., 2008). Self-esteem is defined as “the evaluation which the individual makes and customarily maintains with regard to himself or herself: it expresses an attitude of approval or disapproval toward oneself” (Rosenberg, 1965, p. 5). While many have studied the concept of self-esteem in non-pregnant adults, few have examined the relationship of selfesteem to depression in pregnant women. Jesse and Swanson (2007) found that pregnant women from a rural area who reported low self-esteem were almost three times more likely
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than other women to experience elevated antepartum depressive symptoms. Sowislo and Orth (2012), in a meta-analysis, found that self-esteem was related to depression in non-pregnant adults and that low self-esteem was more likely to predict depression than depression was to predict low selfesteem (N ¼ 77). The authors suggested, however, that more research was needed to determine whether there is a causal relationship between self-esteem and depression. Social support in pregnancy is defined as a woman's appraisal that she is cared for and appreciated by her partner and non-partners (such as a mother or friend) and that they will be there for her, listen to her, share in her pregnancy experiences, offer constructive feedback and tangible aid, and do thoughtful things for her (Brown, 1986; House, 1981). In Jesse and Swanson's (2007) study, women who received less support were almost 2.5 times more likely than other women to experience elevated antepartum depressive symptoms. Some others have noted that poverty, loneliness, isolation from others, and lack of mental health resources may affect satisfaction with social support and self-esteem in rural women (Bloom et al., 2012; Hauenstein & Peddada, 2007; Hillemeier et al., 2008). In Bloom et al.'s study, rural women noted that formal resources were limited and/or too distant. In addition, because of financial hardships, many women lived with extended family, but they often described this as stressful. One woman said, “I don't think it's healthy to always be around family that much. I love ‘em to death, but we're trying to have our own family too, you know?” (p. 816). Glazier, Elgar, Goel, and Holzapfel (2004) are among the few who have examined the relationships of stress, satisfaction with social support, self-esteem, and depressive symptoms among pregnant women, in women living in both rural provinces and urban areas in Canada (N ¼ 2,052). They found that women who reported less support from others reported more stress and depressive symptoms. However, potential mediating effects were not examined. In that large sample, 90% of the pregnant women in their study were married, the majority had higher than average incomes, and over half had college degrees. The participants were also older than the population average for pregnancy in the United States (Martin et al., 2012).
Theoretical Background of Mediation Model This study was guided by Jesse's midrange theory of biopsychosocial-spiritual risk for depression in pregnancy, which has been tested in previous research and supported by years of clinical practice providing care for pregnant women of diverse socioeconomic, racial/ethnic, and cultural backgrounds (Jesse & Alligood, 2002; Jesse & Swanson, 2007). According to Jesse's theory, depressive symptoms result from an interaction of psychosocial risks and resources with the pregnant woman's individual vulnerability that in turn affects her response to stressful life circumstances.
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The theory was augmented by (1) Engel's (1977) theory of a bio-psychosocial approach to health, (2) Lazarus and Folkman's (1984) theory of stress and coping for nonpregnant adults, and (3) Cohen and Wills's (1985) stressbuffering hypothesis. Stressors that can originate either internally or externally (Lazarus & Folkman, 1984) may disrupt the pregnant woman's physical and psychological wellbeing (Woods et al., 2010). Low-income women of color and those living in rural areas may experience many highly stressful situations related to poverty and isolation that can, in turn, directly increase their risk for depression. These include situations such as loss of family, joblessness, lack of housing and/or access to health care, and physical abuse (Jesse & Swanson, 2007; Woods et al., 2010). A pregnant woman's risk for antepartum depression increases proportionally to her level of vulnerability to stress and feelings of being overwhelmed by life circumstances that may exceed her internal and external coping resources (Jesse & Swanson, 2007; Latendresse, 2009). Jesse's framework takes into account the woman's perception of her resources that can, in turn, mediate or buffer depressive symptoms. The pregnant woman's feelings of self-worth/ self-esteem serve as a coping resource, and her satisfaction with social support may help minimize her negative appraisal of the stress event and/or bolster her confidence that she has the internal resources and ability to respond to and address the stress event effectively. The two are related; self-esteem predicted satisfaction with social support in non-pregnant adults (Ottenbreit & Dobson, 2004), and self-esteem and satisfaction with social support were correlated in pregnant women (Curry, Burton, & Fields, 1998; Jesse, Seaver, & Wallace, 2003). It was hypothesized that a pregnant woman's selfesteem and satisfaction with social support are mediators because they have been shown to be affected directly by stress (Curry et al., 1998; Jesse et al., 2003). In turn, stress, satisfaction with social support, and self-esteem each independently predicted risk of depression in pregnancy (Jesse & Swanson, 2007). However, the theoretical propositions that stress, satisfaction with social support, and self-esteem simultaneously affect antepartum depressive symptoms lacks empirical evidence, and therefore these proposed theoretical relationships were examined in this study. Understanding the mediating effects of social support and self-esteem on the relationship between stress and depressive symptoms in rural women is critical for developing intervention strategies as a part of comprehensive prenatal care for low-income rural pregnant women. This secondary analysis of data from the Jesse and Swanson (2007) study was designed to determine whether satisfaction with social support and self-esteem mediated the relationship of antepartum stress with antepartum depressive symptoms among an ethnically and racially diverse group of rural women from the Southeastern United States. The hypothesized models for the relationships
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among the variables (see Fig. 1A and B) are based on Baron and Kenny's (1986) conditions: (a) the antepartum stress (independent variable [IV]) significantly predicts antepartum depressive symptoms (dependent variable [DV]); (b) antepartum stress (IV) significantly predicts satisfaction with social support and self-esteem (mediators); (c) satisfaction with social support and self-esteem (mediators) significantly predict antepartum depressive symptoms (DV) when antepartum stress (IV) is controlled; and (d) for full mediation, the relationship between antepartum stress (IV) and antepartum depressive symptoms (DV) should be reduced to insignificance when satisfaction with social support and self-esteem (mediators) are included in the model. If the fourth condition is not met, partial mediation may be concluded.
Method The Parent Study parent study whose data were used for this secondary analysis was an examination of risk factors for depressive symptoms among a racially and ethnically diverse group of lowincome pregnant women living in rural areas (Jesse & Swanson, 2007). Low-income was defined as receiving Medicaid insurance or being uninsured. While there is no single definition of rural (Coburn et al., 2007), the women in the study were defined as rural because they lived in eastern North Carolina counties classified as rural by the North Carolina Rural Economic Development Center (NCREDC, 2010), based on an average population density of 250 per square mile or less, in the 2010 census. According to the NCREDC, five of these traditionally rural counties have “higher population densities but still retain significant rural characteristics” (p. 1, Rural/Urban Counties in North Carolina). After institutional review board approval, study participants were recruited from a health department, a regional perinatal center, and a private obstetrical practice in the eastern part of a Mid-Atlantic state. Eligible participants were women aged 16–44 years, with a singleton pregnancy between 16 and 28 weeks gestation, and who could understand and speak English or Spanish. Only women in the second trimester were included in order to avoid over-burdening women during their first prenatal interview. All women signed an informed consent form, were interviewed by a research team member either before or after they saw the healthcare provider, and received small gifts as compensation for their time. All responses were coded and deidentified to follow HIPAA privacy rules. To ensure women's safety, the interviewers assessed the level of risk of immediate danger to determine needs for specialty care, follow-up, and referrals based on the practice guidelines developed for the study. Women at potential risk for suicide (n ¼ 14) or harmful situation for themselves
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FIGURE 1. Hypothesized models to test. The hypothesized models were analyzed in stages. Single mediation model tests (A) preceded multiple mediation model tests (B and C). When each mediator is significant in single mediator models, multiple mediator models are proposed and tested further. A shows two single mediator models that test the separate mediational effects of satisfaction with social support and self-esteem on the relationship between antepartum stress and antepartum depressive symptoms. B shows the hypothesized multiple mediator model combining the two significant mediators, self-esteem and satisfaction with social support. C shows a substantively and statistically modified multiple mediator model combining the two significant mediators. This modified multiple mediator model added a predictive link between self-esteem and satisfaction with social support (Ottenbreit & Dobson, 2004). Bolded short arrows (!) indicate measurement errors of each endogenous variable.
and thus their unborn child were immediately referred to a high risk Pregnancy Care Manager (social worker). Women who responded positively to questions about stressful illegal drug and alcohol use (n ¼ 5) or any domestic violence (n ¼ 19), or who scored 16 or higher on the Beck Depression Inventory-II (BDI-II) (n ¼ 104), were given a pocketsized information card containing telephone numbers of drug and alcohol and mental health community resources. Women also were asked if the interview brought up concerns that they would like to discuss with a prenatal care provider; 13 (4%) participants requested and received this follow-up. No participant reported an adverse health outcome during the study.
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Design of the Secondary Data Analysis This secondary analysis of a quantitative dataset from the parent study was conducted using a cross-sectional and descriptive correlation design. Among 324 participants in the parent study, six participants were excluded from the analyses because of missing information on the study variables. Path analysis modeling requires 10–20 subjects for every free parameter estimated and at least 200 in total (Fritz & MacKinnon, 2007; Schumacker & Lomax, 2010). The final sample size (N ¼ 318) was deemed sufficient to test both single and multiple mediation analyses because there were six free parameters estimated in single mediator
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models and 9–10 free parameters estimated in a multiple mediator model.
Measures Sample characteristics. Demographic data collected included age, ethnicity, and insurance status; clinical information included history of pregnancy. Beck Depression Inventory-II. The 21-item Beck Depression Inventory-II (BDI-II) (Beck, Brown, & Steer, 1996) was used to assess antepartum depressive symptoms. Items on the inventory are scored on a 4-point Likert-type scale (range 0–63), with higher scores indicating more depressive symptoms. According to Beck et al. (1996), for non-pregnant adults, a BDI-II score of 0–13 reflects minimal or no symptoms of depression, a score of 14–19 reflects mild depression and higher scores indicate moderate (20– 28), and severe depression (29–63). In this analysis a cut off score of 16 was used to indicate risk for clinical depression because somatic complaints in pregnancy (e.g., sleeping too much or too little, or decreased appetite) can mimic depression. Thus, a BDI-II score of 0–15 was considered to indicate minimal or no risk of antepartum clinical depression based on Holcomb's receiver operating curve analysis showing that this cut-off score was the most likely score to predict antepartum clinical depression (Holcomb, Stone, Lustman, Gavard, & Mostello, 1996; McKee, Cunningham, Jankowski, & Zayas, 2001). Cronbach alpha coefficients for the BDI-II range from .88 to .91 (Jesse & Swanson, 2007; Jesse, Swanson, Newton, & Morrow, 2009). In the study reported here, the Cronbach alpha coefficient was .89. Prenatal Psychosocial Profile. The Prenatal Psychosocial Profile (PPP) (Curry et al., 1998) is a 44-item instrument that includes four subscales used to evaluate antepartum stress, satisfaction with social support from partner and social support from non-partners (family other than a spouse, friends, or a close neighbors), and selfesteem. Its validity and reliability have been tested in over 15 studies with pregnant women (Curry et al., 1998; Jesse & Swanson, 2007; Jesse et al., 2009). Each scale takes less than 5 minutes to administer and is at the 5th to 6th grade reading level. Stress. The PPP stress subscale was developed by Curry et al. (1998) based on the Daily Hassles Scale (Kanner et al., 1981). The 11 items are rated on a 4-point Likert-type scale and scores are summed (range 11–44) with higher scores indicating more stress. Cronbach alpha coefficients range from .63 to .83 (Jesse & Swanson, 2007; Jesse et al., 2009). The Cronbach alpha coefficient in this study was .76. Satisfaction with social support: Partner and non-partner. The two 11-item satisfaction with social support subscales (from partner and non-partners) are rated on a 6-point Likert-type scale and scores are summed, with higher scores indicating greater satisfaction (range 11–66). Cronbach alpha coefficients range from .95
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to .97 for partner support and from .92 to .96 for other support (Jesse & Swanson, 2007; Jesse et al., 2009). Cronbach alpha coefficients for partner and other support in this study were .95 and .94, respectively. In the current study, satisfaction with social support was calculated as the total support received from the woman's partner (married or unmarried) and from non-partners (mother, friends, etc.) (Brown, 1986). Self-esteem. The fourth subscale of the PPP is based on 10 items from the Rosenberg (1965) Self-Esteem Scale that include questions about the person's sense of worth and an additional 11th item, “Feel as though you have control over your life.” Items are rated on a 4-point Likert-type scale and scores are summed, with higher scores indicating greater self-esteem (range 11–44). Cronbach alpha coefficients ranged from .67 to .92 (Jesse & Swanson, 2007; Jesse et al., 2009); the Cronbach alpha in this study was .85.
Data Analysis To test the hypothesized models, single mediation analyses preceded multiple mediation analyses (see Fig. 1A and B). To determine the mediating effects of satisfaction with social support and self-esteem on the relationship of antepartum stress to antepartum depressive symptoms, we used a path analysis with linear regression. Mediation modeling was chosen in order to understand how or why changes occurred in the relationships among the study variables (Baron & Kenny, 1986). The mediation analysis was guided by MacKinnon's (2008) recommendation to test both single mediator and multiple mediator models by using Baron and Kenny's (1986) conditions. A method of biased-corrected bootstrap sampling distribution was used for the mediation tests to overcome the limitations of Baron and Kenny's approach (Krause et al., 2010). The bootstrap method generates new samples by repeated random sampling from original samples. Bias-corrected bootstrapping enables researchers to test hypotheses more accurately than a conventional test such as the Sobel test (Fritz & MacKinnon, 2007; Hayes, 2009; Levy, Landerman, & Davis, 2011). In addition, it can determine the significance of mediated effects and does not require normal distribution of indirect effects (Hayes, 2009; MacKinnon, 2008; Preacher & Hayes, 2004). We used a bias-corrected confidence interval of 95% based on 5,000 bootstrap estimates, as well as bootstrap maximum likelihood (Hayes, 2009; MacKinnon, 2008). The Statistical Package for the Social Sciences (SPSS) 19.0 was used for data management, while the Analysis of Moment Structures (AMOS) was used to assess the hypothesized model's fit to the data and parameter estimation (Arbuckle, 2010). Path analysis using AMOS makes it possible to identify correlations among multiple variables simultaneously by considering measurement errors,
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while regression analysis with SPSS cannot do this (Arbuckle, 2010). The significance-level criterion for all statistical tests was set at a ¼ .05, two-tailed. Pearson correlations and assumption checks were completed before conducting the main mediation analyses. No variables required transformation, no high correlations among independent variables were found, and no outliers were identified. Thus, all statistical assumptions for correlation and regression were met in terms of normality, linearity, homoscedasticity, and independence of error (Meyers, Gamst, & Guarino, 2006). In addition, a multicollinearity diagnostic test was completed based on Meyers et al. (2006) by checking correlation, tolerance, VIF, condition index, and variance proportions; there was no concern of multicollinearity. For descriptive purposes, we defined risk for depression as BDIII 16, but for the mediation analysis a continuous outcome variable, depressive symptoms, was used.
Results
insurance (39.6%); 7.9% had Medicare or were privately insured. On average, participants reported lower levels of stress, higher satisfaction with support from partner and non-partners, and lower depressive symptom scores than each scale midpoint. Hispanic women reported significantly lower levels of antepartum stress, satisfaction with social support, and self-esteem than did African-American and Caucasian women (p < .05 for all). Almost a third of the women had scores of 16 or higher on the BDI-II, indicating a high risk of antepartum depression as defined in this study. However, in the bivariate analysis, risk for antepartum depression was not significantly different among three ethnic/racial groups. Participant characteristics are presented in Table 1. As expected, antepartum stress and antepartum depressive symptoms were positively correlated. Both satisfaction with social support and self-esteem were negatively correlated with antepartum stress and antepartum depressive symptoms (see Table 2).
Description of Study Participants The average age of the 318 women in this study was 24 years (SD ¼ 4.76). The average number of births was .87 (SD ¼ 1.09, range 0–7). The largest percentage of women were African American (43%); fewer women were non-Hispanic Caucasian (31%) or of Hispanic ethnicity (26%). The women had been pregnant, on the average, 2.23 times, and 47.2% of the sample was primiparous. Ninety-two percent of the women were low-income, defined as receiving Medicaid insurance (52.5%) or having no
Single-Mediator Model In single mediation analyses, both satisfaction with social support and self-esteem were partial mediators of the relationship between antepartum stress and antepartum depressive symptoms. The first three conditions suggested by Baron and Kenny (1986) were met, as (a) antepartum stress (IV) significantly predicted antepartum depressive symptoms (DV) (95% confidence interval [CI ] ¼ .378, .563) (Fig. 2A); (b) antepartum stress (IV) significantly predicted
Table 1. Sample Characteristics (N ¼ 318) Variable
Mean
(SD)
Range
Age (years) Gravida Mode Para Mode Race/ethnicity Caucasian African American Hispanic Insurance status No insurance Medicaid Medicare Private or Tricare/Champus Antepartum stress Satisfaction with social support (total) From partner From non-partners (others) Self-esteem Beck Depression Inventory-II BDI-II score < 16 BDI-II score 16
24.16 2.23
(4.76) (1.40)
16–40 1–10
0.87
(1.09)
0–7
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16.03 100.04 53.06 52.27 35.40 13.14
(4.49) (26.77) (13.21) (11.66) (5.06) (8.69)
n
(%)
1
(36.8)
0
(47.2)
100 135 83
(31.4) (42.5) (26.1)
126 167 4 21
(39.6) (52.5) (1.3) (6.6)
214 104
(67.3) (32.7)
11–34 22–132 11–66 11–66 13–44 0–49
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Table 2. Correlation Coefficients of the Study Variables Variable
Antepartum Stress
APDS
Satisfaction With Social Support
— .33 .35
— .41
APDS Satisfaction with social support Self-esteem
.48 .34 .24
Note. APDS, Antepartum depressive symptoms. p < .01.
the two mediators, satisfaction with social support and selfesteem (95% CI ¼ .445, .221; 95% CI ¼ .330, .138, respectively) (Fig. 2B); and (c) both satisfaction with social support and self-esteem significantly predicted depressive symptoms (DV) controlling for antepartum stress (IV) (95% CI ¼ .318, .072; 95% CI ¼ .343, .144) (Fig. 2B).
However, the fourth condition was not met. The direct effect of antepartum stress on depressive symptoms remained significant in the model with satisfaction with social support (95% CI ¼ .299, .516) and in the model with self-esteem (95% CI ¼ .314, .509). In single mediation models, satisfaction with social support had a slightly larger indirect
FIGURE 2. Results of mediator models. Path models with single and multiple mediation analyses illustrate standardized regression coefficients. A shows a direct effect of antepartum stress on antepartum depressive symptoms. All path coefficients are statistically significant in B and C, except a path from satisfaction with social support to antepartum depressive symptoms in C. In C, an unstandardized coefficient value of the path from satisfaction with social support to depressive symptoms was constrained with .037 (exact value from the saturated model) and resulted in .113 as a standardized coefficient value. Circles with arrows (!) indicate unstandardized estimates of variance of errors and all are statistically significant: e1 ¼ 633.946 , e2 ¼ 55.664 , e3 ¼ 24.069 , e4 ¼ 53.662 , e50 ¼ 24.069 , e60 ¼ 552.390 , e70 ¼ 52.919. p < .05, p < .01, p < .001, NS ¼ not significant. Research in Nursing & Health
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Table 3. Direct, Indirect, and Total Effects of Antepartum Stress on Antepartum Depressive Symptoms (Standardized Regression Coefficients) Single-Mediator Models Mediator 1: Satisfaction With Social Support Direct Effect
Mediator 2: Self-Esteem
Indirect Effect
Direct Effect
Indirect Effect
Total Effect
.064
.419
.059
.478
.414
Final Multiple-Mediator Model Direct Effect
Indirect Effect (total)
.390
Total Effect
Indirect Effect (SS)
.088 Indirect Effect (SE)
Indirect Effect (SE ! SS)
.478
.028
.050
.009
Notes. SS, mediated through satisfaction with social support; SE, mediated through self-esteem; SE ! SS, mediated through selfesteem and then satisfaction with social support in sequence. p < .05, p < .01, p < .001.
mediating effect (a1b1 ¼ .064) than did self-esteem (a2b2 ¼ .059), summarized in Table 3 and Figure 2B.
was positively related to satisfaction with social support in pregnancy, and satisfaction with social support and selfesteem were inversely related to antepartum stress (Curry et al., 1998; Jesse et al., 2003). Thus, this modification was accepted in further model tests. The modified multiple-mediator model without any constraint (Model C2 in Table 4) became saturated when over-parameterized to reproduce all of the variances, covariances, and means perfectly, and resulted in a chi-square of 0 with 0 degrees of freedom. Thus, it was impossible to determine statistical significance. To address this, we constrained a path from satisfaction with social support to depressive symptoms, using values ranging from 0 to .037 (Models C3 and C4 in Table 4). The modified multiple-mediator model constrained with .037, which came from the saturated model (Model C2 in Table 4), had almost perfect fit. In addition, Model C4 had chi-square statistics, AIC, and BIC superior to those from other models. Therefore, a modified multiple-mediator model constrained with .037 (Model C4 in Table 4) was chosen. This final model (see Fig. 2C and Table 3) was used to determine the direct,
Multiple-Mediator Models Four competing models were compared: a multiple-mediator model before modification (Model C1); a modified multiple-mediator model without any constraint (Model C2); a modified multiple-mediator model constrained with 0 (Model C3); and a modified multiple-mediator model constrained with .037 (Model C4). A summary of fit comparisons is provided in Table 4. Initially, a multiple-mediator model without any relationship between the two mediators was proposed (Model C1 in Table 4 and Fig. 1B). However, this model poorly described the data and showed poor fit between the hypothesized model and the data. Modification indices suggested by AMOS indicated that self-esteem could predict satisfaction with social support, and this predictive relationship has been supported in a previous study (Ottenbreit & Dobson, 2004). Further, in previous studies, self-esteem
Table 4. Model Fit Indices of Competing Multiple Mediator Models x2(1, n ¼ 318) Good model fit indices
Model C1. (before modification) Model C2. (modified without constraint) Model C3. (modified constrained with 0) Model C4. (modified constrained with-.037)
p
Not significant
43.653
Correspondence to D. Elizabeth Jesse E-mail: [email protected] D. Elizabeth Jesse Associate Professor East Carolina University College of Nursing 3160 Health Sciences Building Greenville, NC 27858 Associate Professor Brody School of Medicine Greenville, NC Heejung Kim School of Nursing University of Kansas Kansas City, Kansas Cynthia Herndon East Carolina University College of Nursing 3160 Health Sciences Building Greenville, NC 27858
Abstract: The purpose of this secondary analysis was to determine whether satisfaction with social support and self-esteem mediated the relationship between antepartum stress and depressive symptoms in women attending prenatal clinics in a rural Southeastern community (N ¼ 318). Path analysis with linear regression indicated that the relationship between antepartum stress and depressive symptoms was partially mediated by higher levels of the internal resources of satisfaction with social support and self-esteem. Self-esteem had a greater influence on the relationship between antepartum stress and depressive symptoms than did satisfaction with social support. These findings suggest further study to determine whether developing culturally tailored interventions that emphasize stress reduction activities in addition to enhancing self-esteem and increasing satisfaction with social support can decrease the burden of antepartum depressive symptoms in rural low-income women. ß 2014 Wiley Periodicals, Inc. Research in Nursing & Health, 2014, 37, 241–252 Accepted 1 April 2014 DOI: 10.1002/nur.21600 Published online 4 May 2014 in Wiley Online Library (wileyonlinelibrary.com).
Pregnancy is a life-changing event that can bring uplifting and positive emotions (Dipietro, Christensen, & Costigan, 2008); at the same time, the physical and emotional changes of approaching motherhood can feel stressful and overwhelming. Up to 51% of pregnant women experience antepartum depressive symptoms, defined as symptoms that do not fully meet the criteria for antepartum depression (American Psychiatric Association [APA], 2013). Among women experiencing depressive symptoms, 11% develop antepartum depression (Bennett, Einarson, Taddio, Koren, & Einarson, 2004; Gaynes et al., 2005), a major unipolar depression with 8–14 symptoms that persist for greater than 2 weeks (APA, 2013). In turn, both antepartum depressive symptoms and depression can lead to adverse infant birth outcomes and postpartum depression (Grigoriadis et al., 2013). In a national study, Witt et al. (2011) found that, compared to pregnant women with no mental health problems, those with poor mental health in pregnancy were over 11 times more likely to report poor mental health postpartum.
This can lead to poor maternal–infant attachment and compromised child development (Field, 2010; Hayes, Goodman, & Carlson, 2013). Women with untreated antepartum depressive symptoms are at twice the risk for preterm birth (Grote et al., 2010; Li, Liu, & Odouli, 2009) and even death by suicide (Palladino, Singh, Campbell, Flynn, & Gold, 2011). Untreated antepartum depressive symptoms disproportionately affect rural, minority and low-income women, who often have inadequate access and availability of health care during pregnancy and little or no health insurance (Bloom, Bullock, & Parson, 2012; Hauenstein & Peddada, 2007; Hauenstein et al., 2006; Hillemeier, Weisman, Chase, & Dyer, 2008; Jesse & Swanson, 2007; Price & Proctor, 2009). Rural women are highly vulnerable to antepartum stress as well as depressive symptoms, especially when a partner or family support system is absent or unsatisfying (Jesse & Swanson, 2007). Although there is a growing body of literature on the relationships among stress, satisfaction with social support, C
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and depressive symptoms in rural pregnant women (Bloom et al., 2012; Hauenstein & Peddada, 2007; Hauenstein et al., 2006; Hillemeier et al., 2008; Jesse & Swanson, 2007; Proctor & Price, 2009), few have used an empirically tested framework to investigate the role of self-esteem in antepartum depression (Jesse & Swanson, 2007), and to our knowledge, none have assessed whether relationships among these three variables could simultaneously affect antepartum depression. Understanding the potential mediator role of satisfaction with social support and self-esteem in the relationship between antepartum stress and depressive symptoms among rural pregnant women may be critical for developing intervention strategies as a part of comprehensive prenatal care. The purpose of this secondary analysis was to determine whether satisfaction with social support and level of self-esteem mediated the relationship between antepartum stress and depressive symptoms in rural pregnant women.
Relationships of Stress, Social Support, and Self-Esteem to Antepartum Depressive Symptoms Psychosocial stress is defined as an imbalance among daily hassles, emotional demands, and coping strategies (Kanner, Coyne, Schaefer, & Lazaus, 1981; Woods, Melville, Guo, Fan, & Gavin, 2010). Perceived life stress is the most commonly cited reason for women experiencing antepartum depressive symptoms (Lancaster et al., 2010; Woods et al., 2010). In Bloom et al.'s (2012) qualitative study (N ¼ 24), Caucasian pregnant women living in a Midwest rural area described high levels of stress caused by financial worries, lack of access to affordable housing, lack of transportation, and unemployment. Over half of these women reported feeling at risk for clinical depression during pregnancy. Jesse and Swanson (2007) found that rural pregnant women at risk for antepartum depression were almost four times more likely to experience negative stress than those at no risk for depression. However, this may be an underestimation, as pregnant women living in rural areas may not reveal their feelings of sadness and depression to professionals or to family, for fear of being labeled “crazy” or being reported to social services as unfit mothers (Jesse, Dolbier, & Blanchard, 2008). Lack of access to adequate mental health resources and transportation problems also prevent them from seeking medical treatment until late stages of a depressive episode, when symptoms are worse and effective intervention is more difficult (Bloom et al., 2012; Jesse et al., 2008). Self-esteem is defined as “the evaluation which the individual makes and customarily maintains with regard to himself or herself: it expresses an attitude of approval or disapproval toward oneself” (Rosenberg, 1965, p. 5). While many have studied the concept of self-esteem in non-pregnant adults, few have examined the relationship of selfesteem to depression in pregnant women. Jesse and Swanson (2007) found that pregnant women from a rural area who reported low self-esteem were almost three times more likely
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than other women to experience elevated antepartum depressive symptoms. Sowislo and Orth (2012), in a meta-analysis, found that self-esteem was related to depression in non-pregnant adults and that low self-esteem was more likely to predict depression than depression was to predict low selfesteem (N ¼ 77). The authors suggested, however, that more research was needed to determine whether there is a causal relationship between self-esteem and depression. Social support in pregnancy is defined as a woman's appraisal that she is cared for and appreciated by her partner and non-partners (such as a mother or friend) and that they will be there for her, listen to her, share in her pregnancy experiences, offer constructive feedback and tangible aid, and do thoughtful things for her (Brown, 1986; House, 1981). In Jesse and Swanson's (2007) study, women who received less support were almost 2.5 times more likely than other women to experience elevated antepartum depressive symptoms. Some others have noted that poverty, loneliness, isolation from others, and lack of mental health resources may affect satisfaction with social support and self-esteem in rural women (Bloom et al., 2012; Hauenstein & Peddada, 2007; Hillemeier et al., 2008). In Bloom et al.'s study, rural women noted that formal resources were limited and/or too distant. In addition, because of financial hardships, many women lived with extended family, but they often described this as stressful. One woman said, “I don't think it's healthy to always be around family that much. I love ‘em to death, but we're trying to have our own family too, you know?” (p. 816). Glazier, Elgar, Goel, and Holzapfel (2004) are among the few who have examined the relationships of stress, satisfaction with social support, self-esteem, and depressive symptoms among pregnant women, in women living in both rural provinces and urban areas in Canada (N ¼ 2,052). They found that women who reported less support from others reported more stress and depressive symptoms. However, potential mediating effects were not examined. In that large sample, 90% of the pregnant women in their study were married, the majority had higher than average incomes, and over half had college degrees. The participants were also older than the population average for pregnancy in the United States (Martin et al., 2012).
Theoretical Background of Mediation Model This study was guided by Jesse's midrange theory of biopsychosocial-spiritual risk for depression in pregnancy, which has been tested in previous research and supported by years of clinical practice providing care for pregnant women of diverse socioeconomic, racial/ethnic, and cultural backgrounds (Jesse & Alligood, 2002; Jesse & Swanson, 2007). According to Jesse's theory, depressive symptoms result from an interaction of psychosocial risks and resources with the pregnant woman's individual vulnerability that in turn affects her response to stressful life circumstances.
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The theory was augmented by (1) Engel's (1977) theory of a bio-psychosocial approach to health, (2) Lazarus and Folkman's (1984) theory of stress and coping for nonpregnant adults, and (3) Cohen and Wills's (1985) stressbuffering hypothesis. Stressors that can originate either internally or externally (Lazarus & Folkman, 1984) may disrupt the pregnant woman's physical and psychological wellbeing (Woods et al., 2010). Low-income women of color and those living in rural areas may experience many highly stressful situations related to poverty and isolation that can, in turn, directly increase their risk for depression. These include situations such as loss of family, joblessness, lack of housing and/or access to health care, and physical abuse (Jesse & Swanson, 2007; Woods et al., 2010). A pregnant woman's risk for antepartum depression increases proportionally to her level of vulnerability to stress and feelings of being overwhelmed by life circumstances that may exceed her internal and external coping resources (Jesse & Swanson, 2007; Latendresse, 2009). Jesse's framework takes into account the woman's perception of her resources that can, in turn, mediate or buffer depressive symptoms. The pregnant woman's feelings of self-worth/ self-esteem serve as a coping resource, and her satisfaction with social support may help minimize her negative appraisal of the stress event and/or bolster her confidence that she has the internal resources and ability to respond to and address the stress event effectively. The two are related; self-esteem predicted satisfaction with social support in non-pregnant adults (Ottenbreit & Dobson, 2004), and self-esteem and satisfaction with social support were correlated in pregnant women (Curry, Burton, & Fields, 1998; Jesse, Seaver, & Wallace, 2003). It was hypothesized that a pregnant woman's selfesteem and satisfaction with social support are mediators because they have been shown to be affected directly by stress (Curry et al., 1998; Jesse et al., 2003). In turn, stress, satisfaction with social support, and self-esteem each independently predicted risk of depression in pregnancy (Jesse & Swanson, 2007). However, the theoretical propositions that stress, satisfaction with social support, and self-esteem simultaneously affect antepartum depressive symptoms lacks empirical evidence, and therefore these proposed theoretical relationships were examined in this study. Understanding the mediating effects of social support and self-esteem on the relationship between stress and depressive symptoms in rural women is critical for developing intervention strategies as a part of comprehensive prenatal care for low-income rural pregnant women. This secondary analysis of data from the Jesse and Swanson (2007) study was designed to determine whether satisfaction with social support and self-esteem mediated the relationship of antepartum stress with antepartum depressive symptoms among an ethnically and racially diverse group of rural women from the Southeastern United States. The hypothesized models for the relationships
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among the variables (see Fig. 1A and B) are based on Baron and Kenny's (1986) conditions: (a) the antepartum stress (independent variable [IV]) significantly predicts antepartum depressive symptoms (dependent variable [DV]); (b) antepartum stress (IV) significantly predicts satisfaction with social support and self-esteem (mediators); (c) satisfaction with social support and self-esteem (mediators) significantly predict antepartum depressive symptoms (DV) when antepartum stress (IV) is controlled; and (d) for full mediation, the relationship between antepartum stress (IV) and antepartum depressive symptoms (DV) should be reduced to insignificance when satisfaction with social support and self-esteem (mediators) are included in the model. If the fourth condition is not met, partial mediation may be concluded.
Method The Parent Study parent study whose data were used for this secondary analysis was an examination of risk factors for depressive symptoms among a racially and ethnically diverse group of lowincome pregnant women living in rural areas (Jesse & Swanson, 2007). Low-income was defined as receiving Medicaid insurance or being uninsured. While there is no single definition of rural (Coburn et al., 2007), the women in the study were defined as rural because they lived in eastern North Carolina counties classified as rural by the North Carolina Rural Economic Development Center (NCREDC, 2010), based on an average population density of 250 per square mile or less, in the 2010 census. According to the NCREDC, five of these traditionally rural counties have “higher population densities but still retain significant rural characteristics” (p. 1, Rural/Urban Counties in North Carolina). After institutional review board approval, study participants were recruited from a health department, a regional perinatal center, and a private obstetrical practice in the eastern part of a Mid-Atlantic state. Eligible participants were women aged 16–44 years, with a singleton pregnancy between 16 and 28 weeks gestation, and who could understand and speak English or Spanish. Only women in the second trimester were included in order to avoid over-burdening women during their first prenatal interview. All women signed an informed consent form, were interviewed by a research team member either before or after they saw the healthcare provider, and received small gifts as compensation for their time. All responses were coded and deidentified to follow HIPAA privacy rules. To ensure women's safety, the interviewers assessed the level of risk of immediate danger to determine needs for specialty care, follow-up, and referrals based on the practice guidelines developed for the study. Women at potential risk for suicide (n ¼ 14) or harmful situation for themselves
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FIGURE 1. Hypothesized models to test. The hypothesized models were analyzed in stages. Single mediation model tests (A) preceded multiple mediation model tests (B and C). When each mediator is significant in single mediator models, multiple mediator models are proposed and tested further. A shows two single mediator models that test the separate mediational effects of satisfaction with social support and self-esteem on the relationship between antepartum stress and antepartum depressive symptoms. B shows the hypothesized multiple mediator model combining the two significant mediators, self-esteem and satisfaction with social support. C shows a substantively and statistically modified multiple mediator model combining the two significant mediators. This modified multiple mediator model added a predictive link between self-esteem and satisfaction with social support (Ottenbreit & Dobson, 2004). Bolded short arrows (!) indicate measurement errors of each endogenous variable.
and thus their unborn child were immediately referred to a high risk Pregnancy Care Manager (social worker). Women who responded positively to questions about stressful illegal drug and alcohol use (n ¼ 5) or any domestic violence (n ¼ 19), or who scored 16 or higher on the Beck Depression Inventory-II (BDI-II) (n ¼ 104), were given a pocketsized information card containing telephone numbers of drug and alcohol and mental health community resources. Women also were asked if the interview brought up concerns that they would like to discuss with a prenatal care provider; 13 (4%) participants requested and received this follow-up. No participant reported an adverse health outcome during the study.
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Design of the Secondary Data Analysis This secondary analysis of a quantitative dataset from the parent study was conducted using a cross-sectional and descriptive correlation design. Among 324 participants in the parent study, six participants were excluded from the analyses because of missing information on the study variables. Path analysis modeling requires 10–20 subjects for every free parameter estimated and at least 200 in total (Fritz & MacKinnon, 2007; Schumacker & Lomax, 2010). The final sample size (N ¼ 318) was deemed sufficient to test both single and multiple mediation analyses because there were six free parameters estimated in single mediator
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models and 9–10 free parameters estimated in a multiple mediator model.
Measures Sample characteristics. Demographic data collected included age, ethnicity, and insurance status; clinical information included history of pregnancy. Beck Depression Inventory-II. The 21-item Beck Depression Inventory-II (BDI-II) (Beck, Brown, & Steer, 1996) was used to assess antepartum depressive symptoms. Items on the inventory are scored on a 4-point Likert-type scale (range 0–63), with higher scores indicating more depressive symptoms. According to Beck et al. (1996), for non-pregnant adults, a BDI-II score of 0–13 reflects minimal or no symptoms of depression, a score of 14–19 reflects mild depression and higher scores indicate moderate (20– 28), and severe depression (29–63). In this analysis a cut off score of 16 was used to indicate risk for clinical depression because somatic complaints in pregnancy (e.g., sleeping too much or too little, or decreased appetite) can mimic depression. Thus, a BDI-II score of 0–15 was considered to indicate minimal or no risk of antepartum clinical depression based on Holcomb's receiver operating curve analysis showing that this cut-off score was the most likely score to predict antepartum clinical depression (Holcomb, Stone, Lustman, Gavard, & Mostello, 1996; McKee, Cunningham, Jankowski, & Zayas, 2001). Cronbach alpha coefficients for the BDI-II range from .88 to .91 (Jesse & Swanson, 2007; Jesse, Swanson, Newton, & Morrow, 2009). In the study reported here, the Cronbach alpha coefficient was .89. Prenatal Psychosocial Profile. The Prenatal Psychosocial Profile (PPP) (Curry et al., 1998) is a 44-item instrument that includes four subscales used to evaluate antepartum stress, satisfaction with social support from partner and social support from non-partners (family other than a spouse, friends, or a close neighbors), and selfesteem. Its validity and reliability have been tested in over 15 studies with pregnant women (Curry et al., 1998; Jesse & Swanson, 2007; Jesse et al., 2009). Each scale takes less than 5 minutes to administer and is at the 5th to 6th grade reading level. Stress. The PPP stress subscale was developed by Curry et al. (1998) based on the Daily Hassles Scale (Kanner et al., 1981). The 11 items are rated on a 4-point Likert-type scale and scores are summed (range 11–44) with higher scores indicating more stress. Cronbach alpha coefficients range from .63 to .83 (Jesse & Swanson, 2007; Jesse et al., 2009). The Cronbach alpha coefficient in this study was .76. Satisfaction with social support: Partner and non-partner. The two 11-item satisfaction with social support subscales (from partner and non-partners) are rated on a 6-point Likert-type scale and scores are summed, with higher scores indicating greater satisfaction (range 11–66). Cronbach alpha coefficients range from .95
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to .97 for partner support and from .92 to .96 for other support (Jesse & Swanson, 2007; Jesse et al., 2009). Cronbach alpha coefficients for partner and other support in this study were .95 and .94, respectively. In the current study, satisfaction with social support was calculated as the total support received from the woman's partner (married or unmarried) and from non-partners (mother, friends, etc.) (Brown, 1986). Self-esteem. The fourth subscale of the PPP is based on 10 items from the Rosenberg (1965) Self-Esteem Scale that include questions about the person's sense of worth and an additional 11th item, “Feel as though you have control over your life.” Items are rated on a 4-point Likert-type scale and scores are summed, with higher scores indicating greater self-esteem (range 11–44). Cronbach alpha coefficients ranged from .67 to .92 (Jesse & Swanson, 2007; Jesse et al., 2009); the Cronbach alpha in this study was .85.
Data Analysis To test the hypothesized models, single mediation analyses preceded multiple mediation analyses (see Fig. 1A and B). To determine the mediating effects of satisfaction with social support and self-esteem on the relationship of antepartum stress to antepartum depressive symptoms, we used a path analysis with linear regression. Mediation modeling was chosen in order to understand how or why changes occurred in the relationships among the study variables (Baron & Kenny, 1986). The mediation analysis was guided by MacKinnon's (2008) recommendation to test both single mediator and multiple mediator models by using Baron and Kenny's (1986) conditions. A method of biased-corrected bootstrap sampling distribution was used for the mediation tests to overcome the limitations of Baron and Kenny's approach (Krause et al., 2010). The bootstrap method generates new samples by repeated random sampling from original samples. Bias-corrected bootstrapping enables researchers to test hypotheses more accurately than a conventional test such as the Sobel test (Fritz & MacKinnon, 2007; Hayes, 2009; Levy, Landerman, & Davis, 2011). In addition, it can determine the significance of mediated effects and does not require normal distribution of indirect effects (Hayes, 2009; MacKinnon, 2008; Preacher & Hayes, 2004). We used a bias-corrected confidence interval of 95% based on 5,000 bootstrap estimates, as well as bootstrap maximum likelihood (Hayes, 2009; MacKinnon, 2008). The Statistical Package for the Social Sciences (SPSS) 19.0 was used for data management, while the Analysis of Moment Structures (AMOS) was used to assess the hypothesized model's fit to the data and parameter estimation (Arbuckle, 2010). Path analysis using AMOS makes it possible to identify correlations among multiple variables simultaneously by considering measurement errors,
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while regression analysis with SPSS cannot do this (Arbuckle, 2010). The significance-level criterion for all statistical tests was set at a ¼ .05, two-tailed. Pearson correlations and assumption checks were completed before conducting the main mediation analyses. No variables required transformation, no high correlations among independent variables were found, and no outliers were identified. Thus, all statistical assumptions for correlation and regression were met in terms of normality, linearity, homoscedasticity, and independence of error (Meyers, Gamst, & Guarino, 2006). In addition, a multicollinearity diagnostic test was completed based on Meyers et al. (2006) by checking correlation, tolerance, VIF, condition index, and variance proportions; there was no concern of multicollinearity. For descriptive purposes, we defined risk for depression as BDIII 16, but for the mediation analysis a continuous outcome variable, depressive symptoms, was used.
Results
insurance (39.6%); 7.9% had Medicare or were privately insured. On average, participants reported lower levels of stress, higher satisfaction with support from partner and non-partners, and lower depressive symptom scores than each scale midpoint. Hispanic women reported significantly lower levels of antepartum stress, satisfaction with social support, and self-esteem than did African-American and Caucasian women (p < .05 for all). Almost a third of the women had scores of 16 or higher on the BDI-II, indicating a high risk of antepartum depression as defined in this study. However, in the bivariate analysis, risk for antepartum depression was not significantly different among three ethnic/racial groups. Participant characteristics are presented in Table 1. As expected, antepartum stress and antepartum depressive symptoms were positively correlated. Both satisfaction with social support and self-esteem were negatively correlated with antepartum stress and antepartum depressive symptoms (see Table 2).
Description of Study Participants The average age of the 318 women in this study was 24 years (SD ¼ 4.76). The average number of births was .87 (SD ¼ 1.09, range 0–7). The largest percentage of women were African American (43%); fewer women were non-Hispanic Caucasian (31%) or of Hispanic ethnicity (26%). The women had been pregnant, on the average, 2.23 times, and 47.2% of the sample was primiparous. Ninety-two percent of the women were low-income, defined as receiving Medicaid insurance (52.5%) or having no
Single-Mediator Model In single mediation analyses, both satisfaction with social support and self-esteem were partial mediators of the relationship between antepartum stress and antepartum depressive symptoms. The first three conditions suggested by Baron and Kenny (1986) were met, as (a) antepartum stress (IV) significantly predicted antepartum depressive symptoms (DV) (95% confidence interval [CI ] ¼ .378, .563) (Fig. 2A); (b) antepartum stress (IV) significantly predicted
Table 1. Sample Characteristics (N ¼ 318) Variable
Mean
(SD)
Range
Age (years) Gravida Mode Para Mode Race/ethnicity Caucasian African American Hispanic Insurance status No insurance Medicaid Medicare Private or Tricare/Champus Antepartum stress Satisfaction with social support (total) From partner From non-partners (others) Self-esteem Beck Depression Inventory-II BDI-II score < 16 BDI-II score 16
24.16 2.23
(4.76) (1.40)
16–40 1–10
0.87
(1.09)
0–7
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16.03 100.04 53.06 52.27 35.40 13.14
(4.49) (26.77) (13.21) (11.66) (5.06) (8.69)
n
(%)
1
(36.8)
0
(47.2)
100 135 83
(31.4) (42.5) (26.1)
126 167 4 21
(39.6) (52.5) (1.3) (6.6)
214 104
(67.3) (32.7)
11–34 22–132 11–66 11–66 13–44 0–49
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Table 2. Correlation Coefficients of the Study Variables Variable
Antepartum Stress
APDS
Satisfaction With Social Support
— .33 .35
— .41
APDS Satisfaction with social support Self-esteem
.48 .34 .24
Note. APDS, Antepartum depressive symptoms. p < .01.
the two mediators, satisfaction with social support and selfesteem (95% CI ¼ .445, .221; 95% CI ¼ .330, .138, respectively) (Fig. 2B); and (c) both satisfaction with social support and self-esteem significantly predicted depressive symptoms (DV) controlling for antepartum stress (IV) (95% CI ¼ .318, .072; 95% CI ¼ .343, .144) (Fig. 2B).
However, the fourth condition was not met. The direct effect of antepartum stress on depressive symptoms remained significant in the model with satisfaction with social support (95% CI ¼ .299, .516) and in the model with self-esteem (95% CI ¼ .314, .509). In single mediation models, satisfaction with social support had a slightly larger indirect
FIGURE 2. Results of mediator models. Path models with single and multiple mediation analyses illustrate standardized regression coefficients. A shows a direct effect of antepartum stress on antepartum depressive symptoms. All path coefficients are statistically significant in B and C, except a path from satisfaction with social support to antepartum depressive symptoms in C. In C, an unstandardized coefficient value of the path from satisfaction with social support to depressive symptoms was constrained with .037 (exact value from the saturated model) and resulted in .113 as a standardized coefficient value. Circles with arrows (!) indicate unstandardized estimates of variance of errors and all are statistically significant: e1 ¼ 633.946 , e2 ¼ 55.664 , e3 ¼ 24.069 , e4 ¼ 53.662 , e50 ¼ 24.069 , e60 ¼ 552.390 , e70 ¼ 52.919. p < .05, p < .01, p < .001, NS ¼ not significant. Research in Nursing & Health
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Table 3. Direct, Indirect, and Total Effects of Antepartum Stress on Antepartum Depressive Symptoms (Standardized Regression Coefficients) Single-Mediator Models Mediator 1: Satisfaction With Social Support Direct Effect
Mediator 2: Self-Esteem
Indirect Effect
Direct Effect
Indirect Effect
Total Effect
.064
.419
.059
.478
.414
Final Multiple-Mediator Model Direct Effect
Indirect Effect (total)
.390
Total Effect
Indirect Effect (SS)
.088 Indirect Effect (SE)
Indirect Effect (SE ! SS)
.478
.028
.050
.009
Notes. SS, mediated through satisfaction with social support; SE, mediated through self-esteem; SE ! SS, mediated through selfesteem and then satisfaction with social support in sequence. p < .05, p < .01, p < .001.
mediating effect (a1b1 ¼ .064) than did self-esteem (a2b2 ¼ .059), summarized in Table 3 and Figure 2B.
was positively related to satisfaction with social support in pregnancy, and satisfaction with social support and selfesteem were inversely related to antepartum stress (Curry et al., 1998; Jesse et al., 2003). Thus, this modification was accepted in further model tests. The modified multiple-mediator model without any constraint (Model C2 in Table 4) became saturated when over-parameterized to reproduce all of the variances, covariances, and means perfectly, and resulted in a chi-square of 0 with 0 degrees of freedom. Thus, it was impossible to determine statistical significance. To address this, we constrained a path from satisfaction with social support to depressive symptoms, using values ranging from 0 to .037 (Models C3 and C4 in Table 4). The modified multiple-mediator model constrained with .037, which came from the saturated model (Model C2 in Table 4), had almost perfect fit. In addition, Model C4 had chi-square statistics, AIC, and BIC superior to those from other models. Therefore, a modified multiple-mediator model constrained with .037 (Model C4 in Table 4) was chosen. This final model (see Fig. 2C and Table 3) was used to determine the direct,
Multiple-Mediator Models Four competing models were compared: a multiple-mediator model before modification (Model C1); a modified multiple-mediator model without any constraint (Model C2); a modified multiple-mediator model constrained with 0 (Model C3); and a modified multiple-mediator model constrained with .037 (Model C4). A summary of fit comparisons is provided in Table 4. Initially, a multiple-mediator model without any relationship between the two mediators was proposed (Model C1 in Table 4 and Fig. 1B). However, this model poorly described the data and showed poor fit between the hypothesized model and the data. Modification indices suggested by AMOS indicated that self-esteem could predict satisfaction with social support, and this predictive relationship has been supported in a previous study (Ottenbreit & Dobson, 2004). Further, in previous studies, self-esteem
Table 4. Model Fit Indices of Competing Multiple Mediator Models x2(1, n ¼ 318) Good model fit indices
Model C1. (before modification) Model C2. (modified without constraint) Model C3. (modified constrained with 0) Model C4. (modified constrained with-.037)
p
Not significant
43.653
