Research was conducted in accordance with ethical principles and guidelines, and reviewed and approved by the Oregon Health Authority, Public Health Division, Institutional Review Board.
Study Recruitment
Study participants were newly enrolled or within 6 visits in MIECHV funded home visiting services in 13 counties in Oregon. Women were 16 years of age or older, spoke either English or Spanish, and either pregnant or parenting a child < 12 months of age. Home visitors asked interested women for their consent to be contacted by the research team, who then sent study information and the baseline survey via either mail or email. Participants also provided consent for their home visitor to provide the research team with regular information about their visits. For clarity, the terms women and participants will refer to those who consented to be in the study.
Data Collection
Participating women completed surveys at study enrollment (baseline) and again 12 months later. Women received a $25 gift card incentive to a local store for completing the Time 1 survey and a $40 gift card at Time 2. Research staff contacted participants monthly between Time 1 and Time 2 to confirm their contact information and support study retention. In all, 132 out of 197 women who expressed initial interest in participating in the study completed a Time 1 survey (67%) and were included in the study. We do not have systematic data on those who chose not to complete the baseline survey, however, some were not eligible due to recruitment window parameters or stated exclusion criteria. Of the 132 Time 1 respondents, 123 (94%) returned a Time 2 survey. Forty-five home visitors working with women provided weekly logs detailing home visiting content. Approximately 90% of expected weekly logs were submitted, with an average of 32.6 logs per family (range 1–60).
Measures: Participant Surveys
Baseline surveys included demographic, and individual and family risk information. Risk factors were identified based on known correlates of negative parenting behaviors, harsh punishment, or extreme parenting stress, selecting brief, validated screening tools whenever possible. In some cases, we worked with state home visiting partners to shorten existing measures to reduce burden to participants. Indicators of psychosocial risk level were: Low social support (the number of people women could turn to for support); Presence of family relationship problems (“none or minor”, “some”, or “serious”); Depression risk (PHQ-9; Kroenke et al. 2001); Presence of interpersonal family violence (Pregnancy Risk Assessment Monitoring System-Phase 6; Centers for Disease Control and Prevention 2009); Maternal substance use (3-item version of the Simple Screening Instrument for Substance Abuse (SSI-SA); Knight et al. 2000); and history of adverse experiences (4-item version of the Adverse Childhood Experiences Questionnaire; Centers for Disease Control and Prevention 2014).
The items on the SSI-SA included three questions asking about drug use and problems related to drugs or alcohol in the past 6 months, and a fourth question about having a current drinking or drug problem. For adverse experiences growing up, respondents indicated if they had ever been in foster care, or if anyone in their family had a problem with drugs or alcohol abuse, depression or mental health issues, or incarceration. We chose not to ask questions about participants’ experience of maltreatment within their family of origin (a known risk factor for negative parenting), given the intrusiveness of these questions in terms of potential for retraumatization and lack of face-to-face support during survey administration. Each indicator was dichotomized to indicate the presence of the risk factor (1 = yes, 0 = no).
Cumulative Risk Factor Index
A cumulative risk factor index was calculated using the sum of 12 dichotomized risk variables including: becoming a mother at 19 or younger, premature birth of their child, less than a high school education, housing instability, household unemployment, single relationship status, low social support, troubled relationships, depression, interpersonal violence, drug problems, and adverse childhood experiences. The substance abuse problem items were dichotomized such that if a mother indicated a positive response to any items (e.g., had used too much, tried to cut down, or felt like she had a drug problem), it was coded as the presence of the drug problems risk factor.
Outcome Measures
Parenting outcomes were collected at Time 1 and Time 2. Parenting knowledge was assessed with the UpStart Parent Survey (USPS) Parenting Knowledge/Skills subscale (Benzies et al. 2013). Parenting attitudes were assessed using Corporal Punishment and Empathy subscales from the Adult Adolescent Parenting Inventory (AAPI-2; Bavolek and Keene 2001). We also used two of three subscales of the Parenting Stress Index-Short Form (PSI-SF), the Parenting Distress (PD) and Parent–Child Dysfunctional Interaction (P-CDI) subscales (Abidin 1995; Haskett et al. 2006), to measure stress related to the parenting role. See Table 1 for example items for measures and reliability data.
Table 1 Parenting outcomes: example of items on measures
Number of Home Visits
Given the variability in the timeframes when home visit logs were collected, we used home visit data housed in the MIECHV Oregon administrative database for home visit total dosage. The program dosage outcome was calculated as the total number of visits received by participants between their enrollment date and the date they completed the Time 2 survey. We also used this strategy due to concerns that the amount of time spent in home visits may have reflected program requirements rather than actual time spent.
Home Visit Content
The content log was developed based on a thorough examination of the literature, review of existing tools (Home Visit Rating Scales; Boller et al. 2009), and in consultation with home visiting research experts and stakeholders. We also incorporated home visiting service areas from the Mother and Infant Home Visiting Program Evaluation study (U.S. Department of Health and Human Services Administration for Children and Families Office of Planning, Research and Evaluation 2015). Content areas were refined based on feedback from home visiting model leads and home visitors about typical visit topics and seemed to have good validity; however, we did not systematically validate this measure. Home visitors accessed an on-line log system to document the estimated time spent during visits in ten specific content areas (see Table 2). Incremental time spent response categories were developed due to the reported difficulty of home visiting staff, and potential inaccuracy, of estimating actual time spent. Response choices for content areas included “did not discuss”, “touched on briefly”, “discussed 10–15 min” and “discussed more than 10–15 min”. Logs were to be completed after each home visit and submitted electronically to the research team, including reporting when no visit occurred for the week.
Table 2 Home visiting content areas and activity log examples
Because there were more actual visits documented in the MIECHV database when compared to number of logs received, we elected to create an overall estimate of time spent on each area across all logs received for a family. First, study content data were collapsed into the four overall topics or domains with similar conceptual focus: self-care, parenting, life course, and support networks/referrals. This average rating was then multiplied by the number of home visits (from MIECHV database) the family received to generate the estimated “content dosage”. Thus, the content dosage variable does not reflect actual time estimates, but provides a proportional representation of the amount of time on a given domain across all visits. For example, two families with a similar average amount of time spent on self-care across home visits, but who had different quantities of home visits, would have different “content dosage” scores for self-care.
Analysis
Multivariate regression models were tested using Time 2 outcome scores for each of the primary parenting outcomes (UpStart, AAPI, and PSI), controlling for scores at Time 1. All models included the following covariates: white/non-white, completed high school (yes/no), marital status, number of adverse childhood experiences (ACEs), and depression risk. To examine whether home visit dosage had differential effects on outcomes for women with higher-risk versus lower-risk profiles, we used the cumulative risk score to calculate multiplicative interaction terms (e.g., number of visits × cumulative risk score) and included terms in the models as predictors. For models testing interaction effects, demographic characteristics included in the cumulative risk score were not included as covariates.