Data Dictionaries

On this page you can find data dictionaries for:

  1. Questionnaires during pregnancy and postpartum (participant responses)
  2. Clinical data (abstracted from medical records)
  3. Diet history during pregnancy (participant response)
  4. Child follow-ups (parent response and measurements by OBS Staff)

Questionnaires During Pregnancy and Postpartum

a) Questionnaire 1 at 11-18 weeks gestational age. This covers much of the demographics and pre-pregnancy history, touching on some pregnancy experiences.

Q1_Data_Dictionary_PublicDownload

b) Questionnaire 2 at 28-25 weeks gestational age. This covers the pregnancy experience and demographics of the biological father.

Q2_Data_Dictionary_PublicDownload

c) Postpartum questionnaire at 6-11 weeks postpartum. This provides an overview of the baby’s habits, breastfeeding and updates on the mother.

Q3_Data_Dictionary_PublicDownload

Clinical Data

This data dictionary has information on what is collected from the medical records of the participant, a possibility because of the integration of the OBS in the hospital system. It is split into 5 main groups of data:

  1. Baseline – demographics, medical and pregnancy history
  2. Antenatal – diagnoses during pregnancy, medication
  3. Delivery – summary of conditions during pregnancy and the events of labour and delivery
  4. Neonatal – birth characteristics of the baby
  5. Specific – extra data is collected in the case of hypertension during pregnancy and for gestational diabetes and threatened preterm labour (in certain cases) to provide researchers with more details that might be useful in their analysis
Clinical_Data_Dictionary_PublicDownload

Diet History

Participants answer the Canadian Diet History Questionnaire II (C-DHQ-II) hosted by the National Cancer Institute between 19-24 weeks gestational age. It is done electronically and more details can be found at: https://epi.grants.cancer.gov/dhq2/ where raw responses and nutrient summaries are available for researchers requesting OBS data.

Child Follow-Ups

The child interviews take place when the children are 8 months, 24 months, 36 months and 54 months of age. Whenever possible, the 24 and 54 month interviews are done in-person with anthropometric measures done by OBS staff. A supplemental questionnaire is done at 36 or 54 months if any previous interview periods were missed to capture some of that data.

OBS_Kids_Data_Dictionary_PublicDownload

In addition to the interviews laid out above, there are some standardised measurement tools used, where the links to the source tool can be found below.

  1. Modified Checklist for Autism in Toddlers, Revised (M-CHAT-R) at 24 months: https://www.mchatscreen.com
  2. The Ages and Stages Questionnaire, version 3 (ASQ-3), 24 and 27 month versions using their described age cut-offs: https://agesandstages.com/products-pricing/asq3/
  3. Maternal sensitivity measure at 24 months, described in: https://doi.org/10.1111/jcpp.12322
  4. National Institutes of Health Toolbox, Cognitive Battery and Parent-Proxy Emotion Battery at 54 months (all materials including age 4), cognitive: https://nihtoolbox.org/domain/cognition/, emotion: https://nihtoolbox.org/domain/emotion/