Coding of occupation for the "young cohort" of the Danish twin register. A resource for future epidemiologic research.

OBJECTIVES

Information on health-related outcomes and exposures is available in user-friendly computerized format for the "young cohort" of the Danish Twin Register born 1953-82. We incorporated occupation information within the database to facilitate future job-related studies.

METHODS

Occupation information for the 29,430 twins responding to a mailed questionnaire in 1995 was coded according to DISCO-88. The subjects were classified in three ways depending on the information available: directly from the 2,196 job titles listed in the DISCO-88 handbook, according to a set of predetermined rules, or by consensus if ambiguous information was provided. Two percent (2%) of the sample was recoded independently by two investigators to demonstrate coding consistency.

RESULTS

Occupation could be directly coded using job titles for 61% of the sample; 15% were coded according to a set of rules or by consensus; 24% could not be coded. The recoded sample was 99% in agreement with the original coding.

CONCLUSION

Occupation information has been incorporated within the extensive health-related database for the "young cohort" of the Danish Twin Register. This resource is available to researchers for future studies concerning occupation, health, and heredity using (1) the existing data (2) via linkage to other Danish databases, or (3) by contacting selected subjects directly.