Intimate Partner Abuse and Postpartum Mental Health Problems
Intimate Partner Abuse and Postpartum Mental Health Problems
The Research Ethics Boards of the University of British Columbia, the Children's and Women's Health Centre of British Columbia, and the Vancouver Coast Health Research Institute approved this study. All participants provided written informed consent.
The study population was English-speaking mothers aged 18 years and older in the metropolitan area of a large, western Canadian city who were within three months postpartum. Women were recruited to participate in a one-time interview of factors that may affect women's health and well-being after pregnancy. The study was advertised in area hospitals, local newspapers, and community venues frequented by new mothers (e.g., recreational centers, yoga and fitness studios, community centers, women's centers), as well as on websites targeting new mothers and on websites of other relevant organizations (e.g., community websites). The recruitment materials did not specify a focus on intimate partner abuse or mental health, but rather described a broad interest in experiences occurring before and during pregnancy that may be associated with health and well-being after pregnancy. In total, 100 women participated in the study.
Depression, Anxiety and Stress Scales (DASS-21). The DASS-21 is a 21-item self-report questionnaire designed to measure the severity of a range of symptom common to depression, anxiety, and tension/stress. Each of the three DASS-21 scales contains seven items. Respondents use a 4-point scale to rate the extent to which they have experienced each state over the past week. Each item is scored from 0 (did not apply to me at all) to 3 (applied to me very much or most of the time). Scores for Depression, Anxiety and Stress are calculated by summing relevant item ratings and multiplying by a factor of two. Total scores are calculated in the same way, using all items. In the present study, reliability of the scale scores ranged from adequate (α = .67 for Anxiety) to excellent (α = .87 for Stress). Reliability of the total scores was excellent (α = .89).
Severity of symptomatology was calculated for each subscale following the guidelines provided by the DASS-21 developers. Specifically, for the Depression scale, scores from 0–9 indicate normal levels of depressive symptoms; scores of 10–13 indicate mild symptoms; scores of 14–20 indicate moderate symptoms; scores of 21–27 indicate severe symptoms; and scores greater or equal to 28 indicate extreme symptoms. For the Anxiety scale, scores from 0–7 indicate normal levels of depressive symptoms; scores of 8–9 indicate mild symptoms; scores of 10–14 indicate moderate symptoms; scores of 15–19 indicate severe symptoms; and scores greater or equal to 20 indicate extreme symptoms. For the Stress scale, scores from 0–7 indicate normal levels of depressive symptoms; scores of 8–9 indicate mild symptoms; scores of 10–14 indicate moderate symptoms; scores of 15–19 indicate severe symptoms; and scores greater or equal to 20 indicate extreme symptoms.
Yale-Brown Obsessive-compulsive Scale (YBOCS). The YBOCS measures the presence and severity of obsessive-compulsive disorder symptoms. The instrument is divided into the Obsessions scale and the Compulsions scale. For each scale, five aspects of obsessive and compulsive pathology are each rated on a scale ranging from 0 (no symptoms) to 4 (extreme symptoms): time spent, degree of interference, distress, resistance (greater resistance is assigned lower scores), and perceived control over the symptom. Subscale scores are summed to yield a total score. In the present study, reliability of the Obsessions and Compulsions scales was excellent (both α = .90), as was reliability of the total scores (α = .93).
As for the DASS-21, severity of obsessive-compulsive disorder symptomatology can be calculated using the YBOCS total scores following the guidelines provided by the instrument developers. Specifically, scores from 0–7 indicate subclinical levels of obsessive-compulsive disorder symptoms; scores of 8–15 indicate mild symptoms; scores of 16–23 indicate moderate symptoms; scores of 24–31 indicate severe symptoms; and scores greater or equal to 32 indicate extreme symptoms.
Posttraumatic Stress Disorder Symptom Scale (PSS-SR). The PSS-SR is a 17-item self-report measuring posttraumatic stress disorder symptomatology which directly corresponds to Diagnostic and Statistical Manual of Mental Disorders-III-Revised (DSM-III-R) criteria. For all items, symptom frequency over the preceding two weeks is reported on a 4-point scale, where 0 = not at all, 1 = once per week, 2 = 2 to 4 times per week, and 3 = 5 or more times per week. A total score is obtained by summing each symptom rating. Typically, total scores of 14 or greater indicate symptom severity consistent with posttraumatic stress disorder. Scale scores are calculated by summing symptoms in the re-experiencing (4 items), avoidance (7 items), and arousal (6 items) clusters. In the present study, reliability of the scale scores was good (α = .76-.80) and reliability of the total scores was excellent (α = .90).
Conflict Tactics Scale Revised (CTS-2). The CTS2 is a self-report, behavioral measure of psychological aggression (8 items), physical assault (12 items), sexual coercion (7 items), physical injury (6 items), and negotiation (6 items) occurring in the context of conflict between intimate partners. The 39 items are rated on a 8-point frequency scale (never, once, twice, 3–5 times, 6–10 times, 11–20 times, and more than 20 times, not in the past year but it did happen before) in terms of the respondent and her partner's behaviors. This study used the CTS2 items that assessed the partner's violent behaviors toward our participants. Because of our focus on intimate partner abuse rather than relationship behaviors more broadly, the negotiation scale items were excluded from analyses. Response options were modified to query whether or not the behavior occurred within each of two specified periods: as an adult before the woman became pregnant and during the pregnancy. Specifically, for each item, first participants were asked whether the behavior had occurred during pregnancy (yes, no), and second they were asked whether it had occurred at any point in her life prior to pregnancy (yes, no).
For each of the CTS2 scales used in this study, women were classified as having been victims of the particular type of abuse if they reported experiencing one or more of the scale items within the relevant time period. For example, a woman who reported having experienced one or more of the 8 psychological aggression items at some point prior to getting pregnant would be classified as having been a victim of psychological aggression before pregnancy. We then calculated overall prevalence (yes, no) and prevalence by type (psychological, physical, sexual) and severity (minor, severe) of intimate partner abuse for each time period following the guidelines detailed in the CTS2 coding manual. We additionally created variables describing the number of types of intimate partner abuse experienced during each reference period, collapsing across participants who experienced 2 or 3 types of abuse due to small cell sizes (0, 1, 2 or 3). Reliability of the modified CTS2 scores was good to excellent (α = .75 or greater).
Procedures. Potential participants contacted us via secure phone or email, at which time they were screened for eligibility and interviews were scheduled. Participants completed the study measures during semi-structured, calendar-based interviews conducted by female research assistants at safe locations of the women's choice. Briefly, calendar-based interviews are the state-of-the-art in surveying and interviewing. These methods require respondents to retrospectively report, using a calendar as a memory aid. Personally significant and easy-to-remember landmark dates are marked on the calendar to serve as temporal anchors. In the present study, the delivery date was used to calculate the approximate date of conception. These two dates then served as the primary temporal anchors. Additional anchors included dates of admission and discharge to the hospital.
Following the interviews, information regarding local mental health services and abuse resources (e.g., helpline phone numbers, shelter information, legal services, etc.) was provided as necessary. Women received an honorarium of $20 for their participation, and up to $5 for expenses associated with participation (e.g., parking, bus or cab fare).
Statistical Analyses. We calculated descriptive statistics for all variables and conducted bivariate analyses to examine women's mean levels of postpartum mental health symptoms by their sociodemographic characteristics (participant age, race/ethnicity, education, income, relationship status, and prior children) and by prevalence (yes, no) of each type of intimate partner abuse (psychological, physical, and sexual) both before pregnancy and during pregnancy. To answer our research questions, we then tested a series of multivariate analysis of covariance models. Specifically, to answer our first two research questions, we tested two multivariate analysis of covariance models with psychological, physical and sexual abuse (yes, no) as the dichotomous independent variables and symptoms of stress, anxiety, depression, obsessive-compulsive disorder, and posttraumatic stress disorder as the continuous dependent variables, controlling for participant characteristics. To answer our third research question, we tested two additional multivariate analysis of covariance models with number of types of intimate partner abuse experienced before and during pregnancy as the categorical predictors and symptoms of stress, anxiety, depression, obsessive-compulsive disorder, and posttraumatic stress disorder as the continuous dependent variables, again controlling for participant characteristics. Statistical significance was set at α = .05. All analyses were conducted with IBM SPSS Statistics 21.
Methods
The Research Ethics Boards of the University of British Columbia, the Children's and Women's Health Centre of British Columbia, and the Vancouver Coast Health Research Institute approved this study. All participants provided written informed consent.
Study Population and Recruitment
The study population was English-speaking mothers aged 18 years and older in the metropolitan area of a large, western Canadian city who were within three months postpartum. Women were recruited to participate in a one-time interview of factors that may affect women's health and well-being after pregnancy. The study was advertised in area hospitals, local newspapers, and community venues frequented by new mothers (e.g., recreational centers, yoga and fitness studios, community centers, women's centers), as well as on websites targeting new mothers and on websites of other relevant organizations (e.g., community websites). The recruitment materials did not specify a focus on intimate partner abuse or mental health, but rather described a broad interest in experiences occurring before and during pregnancy that may be associated with health and well-being after pregnancy. In total, 100 women participated in the study.
Measures
Depression, Anxiety and Stress Scales (DASS-21). The DASS-21 is a 21-item self-report questionnaire designed to measure the severity of a range of symptom common to depression, anxiety, and tension/stress. Each of the three DASS-21 scales contains seven items. Respondents use a 4-point scale to rate the extent to which they have experienced each state over the past week. Each item is scored from 0 (did not apply to me at all) to 3 (applied to me very much or most of the time). Scores for Depression, Anxiety and Stress are calculated by summing relevant item ratings and multiplying by a factor of two. Total scores are calculated in the same way, using all items. In the present study, reliability of the scale scores ranged from adequate (α = .67 for Anxiety) to excellent (α = .87 for Stress). Reliability of the total scores was excellent (α = .89).
Severity of symptomatology was calculated for each subscale following the guidelines provided by the DASS-21 developers. Specifically, for the Depression scale, scores from 0–9 indicate normal levels of depressive symptoms; scores of 10–13 indicate mild symptoms; scores of 14–20 indicate moderate symptoms; scores of 21–27 indicate severe symptoms; and scores greater or equal to 28 indicate extreme symptoms. For the Anxiety scale, scores from 0–7 indicate normal levels of depressive symptoms; scores of 8–9 indicate mild symptoms; scores of 10–14 indicate moderate symptoms; scores of 15–19 indicate severe symptoms; and scores greater or equal to 20 indicate extreme symptoms. For the Stress scale, scores from 0–7 indicate normal levels of depressive symptoms; scores of 8–9 indicate mild symptoms; scores of 10–14 indicate moderate symptoms; scores of 15–19 indicate severe symptoms; and scores greater or equal to 20 indicate extreme symptoms.
Yale-Brown Obsessive-compulsive Scale (YBOCS). The YBOCS measures the presence and severity of obsessive-compulsive disorder symptoms. The instrument is divided into the Obsessions scale and the Compulsions scale. For each scale, five aspects of obsessive and compulsive pathology are each rated on a scale ranging from 0 (no symptoms) to 4 (extreme symptoms): time spent, degree of interference, distress, resistance (greater resistance is assigned lower scores), and perceived control over the symptom. Subscale scores are summed to yield a total score. In the present study, reliability of the Obsessions and Compulsions scales was excellent (both α = .90), as was reliability of the total scores (α = .93).
As for the DASS-21, severity of obsessive-compulsive disorder symptomatology can be calculated using the YBOCS total scores following the guidelines provided by the instrument developers. Specifically, scores from 0–7 indicate subclinical levels of obsessive-compulsive disorder symptoms; scores of 8–15 indicate mild symptoms; scores of 16–23 indicate moderate symptoms; scores of 24–31 indicate severe symptoms; and scores greater or equal to 32 indicate extreme symptoms.
Posttraumatic Stress Disorder Symptom Scale (PSS-SR). The PSS-SR is a 17-item self-report measuring posttraumatic stress disorder symptomatology which directly corresponds to Diagnostic and Statistical Manual of Mental Disorders-III-Revised (DSM-III-R) criteria. For all items, symptom frequency over the preceding two weeks is reported on a 4-point scale, where 0 = not at all, 1 = once per week, 2 = 2 to 4 times per week, and 3 = 5 or more times per week. A total score is obtained by summing each symptom rating. Typically, total scores of 14 or greater indicate symptom severity consistent with posttraumatic stress disorder. Scale scores are calculated by summing symptoms in the re-experiencing (4 items), avoidance (7 items), and arousal (6 items) clusters. In the present study, reliability of the scale scores was good (α = .76-.80) and reliability of the total scores was excellent (α = .90).
Conflict Tactics Scale Revised (CTS-2). The CTS2 is a self-report, behavioral measure of psychological aggression (8 items), physical assault (12 items), sexual coercion (7 items), physical injury (6 items), and negotiation (6 items) occurring in the context of conflict between intimate partners. The 39 items are rated on a 8-point frequency scale (never, once, twice, 3–5 times, 6–10 times, 11–20 times, and more than 20 times, not in the past year but it did happen before) in terms of the respondent and her partner's behaviors. This study used the CTS2 items that assessed the partner's violent behaviors toward our participants. Because of our focus on intimate partner abuse rather than relationship behaviors more broadly, the negotiation scale items were excluded from analyses. Response options were modified to query whether or not the behavior occurred within each of two specified periods: as an adult before the woman became pregnant and during the pregnancy. Specifically, for each item, first participants were asked whether the behavior had occurred during pregnancy (yes, no), and second they were asked whether it had occurred at any point in her life prior to pregnancy (yes, no).
For each of the CTS2 scales used in this study, women were classified as having been victims of the particular type of abuse if they reported experiencing one or more of the scale items within the relevant time period. For example, a woman who reported having experienced one or more of the 8 psychological aggression items at some point prior to getting pregnant would be classified as having been a victim of psychological aggression before pregnancy. We then calculated overall prevalence (yes, no) and prevalence by type (psychological, physical, sexual) and severity (minor, severe) of intimate partner abuse for each time period following the guidelines detailed in the CTS2 coding manual. We additionally created variables describing the number of types of intimate partner abuse experienced during each reference period, collapsing across participants who experienced 2 or 3 types of abuse due to small cell sizes (0, 1, 2 or 3). Reliability of the modified CTS2 scores was good to excellent (α = .75 or greater).
Procedures. Potential participants contacted us via secure phone or email, at which time they were screened for eligibility and interviews were scheduled. Participants completed the study measures during semi-structured, calendar-based interviews conducted by female research assistants at safe locations of the women's choice. Briefly, calendar-based interviews are the state-of-the-art in surveying and interviewing. These methods require respondents to retrospectively report, using a calendar as a memory aid. Personally significant and easy-to-remember landmark dates are marked on the calendar to serve as temporal anchors. In the present study, the delivery date was used to calculate the approximate date of conception. These two dates then served as the primary temporal anchors. Additional anchors included dates of admission and discharge to the hospital.
Following the interviews, information regarding local mental health services and abuse resources (e.g., helpline phone numbers, shelter information, legal services, etc.) was provided as necessary. Women received an honorarium of $20 for their participation, and up to $5 for expenses associated with participation (e.g., parking, bus or cab fare).
Statistical Analyses. We calculated descriptive statistics for all variables and conducted bivariate analyses to examine women's mean levels of postpartum mental health symptoms by their sociodemographic characteristics (participant age, race/ethnicity, education, income, relationship status, and prior children) and by prevalence (yes, no) of each type of intimate partner abuse (psychological, physical, and sexual) both before pregnancy and during pregnancy. To answer our research questions, we then tested a series of multivariate analysis of covariance models. Specifically, to answer our first two research questions, we tested two multivariate analysis of covariance models with psychological, physical and sexual abuse (yes, no) as the dichotomous independent variables and symptoms of stress, anxiety, depression, obsessive-compulsive disorder, and posttraumatic stress disorder as the continuous dependent variables, controlling for participant characteristics. To answer our third research question, we tested two additional multivariate analysis of covariance models with number of types of intimate partner abuse experienced before and during pregnancy as the categorical predictors and symptoms of stress, anxiety, depression, obsessive-compulsive disorder, and posttraumatic stress disorder as the continuous dependent variables, again controlling for participant characteristics. Statistical significance was set at α = .05. All analyses were conducted with IBM SPSS Statistics 21.