DNBC Interviews 1 - 4
The four computer-assisted telephone interviews were carried out in gestational week 12 and 30 as well as when the child was 6 and 18 months old. Each interview lasted approx. 10-15 minutes.
Respons rates were high for the first two interviews, but dropped as the child got older and the mothers returned to work.
| Data sweep | Invited | Responders | Response rate | Codebook |
| Enrolments | 101,042 | |||
| Interview 1 | 92,892 | 92% | Yes, DK and English | |
| Interview 2 | 87,802 | 87% | Yes, DK and English | |
| FFQ | 72,821 | 72% | pdf of questionnaire | |
| Interview 3 | 70,292 | 69% | Yes, DK and English | |
| Interview 4 | 66,764 | 65% | Yes, DK and English |
Focus areas in the two pre-natal questionnaires
- Earlier pregnancies and childbirths, IVF treatment
- Health in general and during pregnancy as well as medical pregnancy examinations
- Drug use
- Work environment
- Home environment
- Diet - vitamins - dietary supplements
- Use of alcohol and tobacco
- Sleep
- Exercise
- Oestrogen
- Socio-economic variables
- Psycho-social stress
Focus areas in the two post-natal questionnaires
- Child diet
- Child development
- Child vaccinations
- Follow-up on pre-natal questions
Code books for all four interviews
English version of code books for interviews 1 - 4
Danish version of code books for interviews 1 - 4
The interviews were carried out under DNBC supervision
The interviewer guides - in Danish - were drafted by DNBC supervisors in collaboration with the phoning companies. The guides contain guidelines for the interviewer for every question.