Summary of measures at baseline and 34–36 weeks’ gestation
| Measurement construct and description | Scoring |
|---|---|
| Sociodemographic characteristics26 | |
| Age and cultural background (baseline only); marital status, education and income, where income was defined as pretax annual income from all sources of employment including unreported income and excluding any money received from family, friends or income assistance | Single (not married or common-law); limited education (having less than high school); low income (living on a less than $20 000/yr); all dichotomous (yes/no) variables |
| Unstable housing | |
| Having to move 3 or more times or experiencing homelessness (past yr). | Dichotomous (yes/no) variable |
| Psychological distress | |
| Kessler Psychological Distress Scale27; Likert scale with 10 items (e.g., “About how often did you feel hopeless?”) | Moderate-to-severe anxiety or depression |
| Experiences of violence | |
| Child maltreatment; Childhood Trauma Questionnaire, Short Form;28 Likert scale with 28 items (e.g., “When I was growing up, I didn’t have enough to eat”) | Moderate-to-severe levels of neglect, physical abuse, emotional abuse and/or sexual abuse |
| Intimate partner violence (past yr); Composite Abuse Scale;29 Likert scale with 30 items (e.g., “My partner told me that I wasn’t good enough”); partner was defined as husband or wife, partner, or boyfriend or girlfriend for longer than 1 mo | Sum of 30 items (range, 0 [never] to 5 [daily]); a score of 3 or more was used as the criterion for exposure to intimate partner violence |
| Prenatal substance use30 | |
| Tobacco (no. of cigarettes smoked in past 2 d) | Count |
| Alcohol (frequency of drinking in past month) | Frequency; dichotomous (yes/no) variable |
| Cannabis (frequency of using all forms of cannabis, marijuana or hashish in past mo) | Frequency; dichotomous (yes/no) variable |
| Street drugs (frequency of using LSD, magic mushrooms, ecstasy, cocaine, speed, heroin or crystal methamphetamines or any combination in past mo) | Frequency; dichotomous (yes/no) variable |
| Any substance (use of any or all of tobacco, alcohol, cannabis and street drugs) | Frequency; dichotomous (yes/no) variable |
Note: LSD = lysergic acid diethylamide.