Introduction
The table below summarises the measures used in the 1st Contact booklet. Each measure is identified by the booklet heading and pages, and by informal or formal names and descriptions. The number of items in each measure is shown, but note that some of these items have two or more parts, giving two or more item variables.
The final column of the table shows derived variables that are related to each measure; each variable name here is a link that will take you to the relevant item in the 1st Contact derived variables page.
Measures in the Booklet
Refer to the annotated booklet (pdf) for section headings and page numbers, as well as for item variable names and coding.
| Booklet section, pages | No. of items | Description of measure | References | Related derived variables |
|---|---|---|---|---|
| Consent Form (first page, not numbered) |
7 | Confirmation of parent's name, relationship to twins, address and
phone number, and signed consent |
Included for admin reasons, to confirm contact details and as proof of consent. | - |
| You and Your Twins, page 1 |
25 | (1) Contact details (21 items):
parent name, sex, address and phone number; contact details for a relative or friend; twin names, sexes and birth dates. (2) Ethnic origin of twins (3 items). (3) Main language spoken at home (1 item). |
Items added by TEDS researchers; requested by all collaborators. | - |
| Your Twins Day to Day, pages 2-5 |
27 | (1) Membership of twins' club: item 1. (2) Breast-feeding the twins: item 2. (3) Feeding the twins: items 3-6. (4) Dressing the twins: items 7, 8. (5) Sleeping, putting twins to bed: items 9-13. (6) Looking after the twins: items 14-17. (7) Details of younger and older siblings: items 18-20. (8) Changes relating to older sibs and twins: items 21-25. (9) Is mother pregnant: item 26. |
Breast-feeding, sibling details, and pregnancy items (2, 18-20, 26)
added by TEDS researchers; requested by all collaborators. All other items added by Multiple Births Foundation. |
- |
| Your Twins: Identical or Non-Identical, pages 6-8 |
18 | Zygosity questionnaire, slightly modified from Goldsmith | Goldsmith, H.H. (1991): A zygosity questionnaire for young twins: a research note; Behaviour Genetics, 21, 257-269. | Blood groups and factors: azyfac, azytyp Zygosities: atempzyg, aalgzyg, aalg2zy |
| Information about the Adults in the Home, pages 9-10 |
24 | (1) Respondent's name, sex, birth date and relationship to twins: 6
items (not numbered). (2) Respondent's educational qualifications, job and marital status: items 46-51. (3) Partner's name, sex, birth date and relationship to twins: 6 items (not numbered). (4) Partner's educational qualifications, job and marital status: items 52-57. |
Background information on carer(s) of the twins added by TEDS
researchers, and requested by all collaborators. Respondent and partner work-related items (47-50, 53-56) are based on the requirements for standard social class categories, as described by: Office of Population and Census Surveys (1991): Standard occupational classification, volume 3: social classifications and coding methodology; London: Her Majesty's Stationery Office. See also: Hernandes, D.J. (1997): Child development and the social demography of childhood; Child Development, Vol 68(1), 149-169. |
Parent ages: arespage, apartage, amumage, adadage, amumagetw, adadagetw Family status: aadults Parent qualifications: amohqual, afahqual Parent employment types: amoclas, afaclas, amosoc, afasoc, amojob, afajob, amospq, afaspq, amowork, afawork Mother's age at birth of first child: amagechl SES composite: ases |
| Mother's Pregnancy and Birth, pages 11-14 |
27 | (1) Twin names: 2 items (not numbered). (2) Problems, etc, during mother's pregnancy: 8 items (58-65). (3) Labour and birth of twins: 8 items (66-73). (4) Concerns and special care after birth: 3 items (74-76). (5) Twin medical problems since birth: 4 items (77-80). (6) Twin handedness: 1 item (81). |
Questions based on several sources: (1) MacArthur Longitudinal Twin Study (MALTS): contact Robert Plomin. (2) Avon Longitudinal Study of Pregnancy and Childhood (ALSPAC) questionnaires: contact Judy Dunn. (3) Mike Rutter's questionnaires (1994). (4) Twins at Birth Risk Assessment Scale (TABRAS): Dieter Wolke and Gesina Koeppen-Schomerus, University of Hertfordshire. (5) Personal Child Health Records from hospitals. (6) Western Reserve Twin Project Cognitive QTL Replication Study: perinatal questions. (7) Parnas, J., Schulsinger, F. et al (1982): Perinatal complications and clinical outcome within the schizophrenia spectrum; British Journal of Psychiatry, 140, 416-420. (8) Dorothy Bishop's MRC twin study questionnaire. |
Twin lengths and weights at birth: ablen1/2, akidgr1/2 Medical risk composites: amedtot, atwmed1/2 Perinatal outliers composites: aperi1x, aperi2x, aperi3x, aperi4x, aperi5x, aperinat |
| Your Twins' Hearing, page 15 |
8 | Items added by Mark Haggard for the Hearing sub-study. | - | - |
| Medical Records Consent Form (last page, not numbered) |
14 | (1) Confirmation of respondent's name, birth date, address. (2) Respondent's NHS and NI numbers. (3) Name and address of the hospital where the twins were born, and the consultant's name. (4) Consent for TEDS to request hospital records, with signature and date. |
Items added for admin reasons, to enable access to medical records if required. | - |