Over 50's (Aged)
Study Code:AG
Sample:4562 twins
Start Date:Jan.1993
Contact:Anjali Henders
More Info:QIMR only


The Over 50's study was conducted as a multi-wave mailout to pairs of twins on the Australian Twin Registry (ATR) who were over 50 years of age. In total, 4562 twins (2281 pairs) were recruited for the survey, of whom 3116 individuals (1279 complete pairs and 558 singles) completed and returned the 16-page questionnaire form. A further 286 responses were obtained via an abbreviated two-page telephone questionnaire from twins who refused to complete the full questionnaire (107 co-twins of singles who completed the full survey, 58 twin pairs, 63 singles).

The initial database contained 4186 twins of whom 2353 (1176 pairs + 1 single) were selected for the Wave 1 mailout in November 1993. The selected twins were those who were not part of Cohort 1, as these were participating in the Semi-Structured Assessment for the Genetics of Alcoholism (SSAGA) survey at the time. 295 twins from Wave 1 who refused to fill out the full survey form agreed to answer a considerably abbreviated telephone survey. Wave 2 occurred in October 1994, and consisted of 376 new twins appended from the ATR who had turned 50 in the intervening period since Wave 1, plus the pairs of twins from Cohort 1. However, all Victorian twins were excluded since the mailout coincided with the Melbourne SSAGA BLOOD bleeding program. In total 1296 twins (648 pairs) were selected for this mailout. Wave 3 occurred in July 1995, and consisted of those 864 twins (432 pairs) who were excluded previously.

49 twins who were present on the Wave 1 list from ATR were absent from the updated Wave 2 list, presumably due to their death or being marked for deletion in the intervening 12 month period. Survey forms were not sent to these twins, however their details remain in the study database.

Questionnaire Contents

  • Personal details
  • General health
  • Personality
  • Relationships
  • Life events
  • Smoking
  • Alcohol
  • Exercise
  • Anxiety and depression
  • Bones and joints
  • Health conditions checklist
  • Vitamins and supplements
  • Sun exposure