A national pilot study to inform the design of a Longitudinal Interdisciplinary National Data on Ageing for Australia (LINDA)

Background and Objectives: To better inform service provision and social services, Australia has long needed a comprehensive national ageing study that is comparable with international ageing studies and eligible to join the register of harmonized cross-national studies of ageing. We conducted a pilot study to fill this gap in Australia's social and health data collection on ageing. Research Design and Methods: We utilized online computer-assisted web interviewing (CAWI) and a follow-up Telephone Interview for Cognitive Status (TICS) screening. Participants were drawn from a Roy Morgan Consumer Panel using random probability sampling. Data collected were compared with the national Census data. Results: Among 1172 online CAWI survey participants (mean age: 65.8 years; 51.0% female), 46.8% had a chronic health condition or disability, 26.1% were full-time employed, and 46.8% were fully or partially retired. Compared with 2021 Australian Census data, the sample was broadly representative by age, sex, geographic region, and health, but respondents tended to have higher education levels (66% reported completing secondary schooling vs 42% in the Census) and underrepresented culturally and linguistically diverse backgrounds (21% born overseas vs 39%; 4% speak a language other than English at home vs 23%); 804 respondents completed TICS (mean[SD] = 33.6[2.8]; range: 22-41), with 71.4% classified as cognitively normal, 27.7% ambiguous, and 1.1% cognitively impaired. Discussion and Implications: This pilot demonstrated the feasibility of online and telephone-based data collection with cognitive screening to capture demographic and health profiles of older Australians, providing a strong foundation for future large-scale national ageing studies.