The English Longitudinal Study of Ageing (ELSA) is a panel study of a representative cohort of men and women living in England aged ≥50 years. The study collects objective and subjective measures of physical and mental health, wellbeing, finances and attitudes around ageing and how these change over time.

ELSA was designed as a sister study to the Health and Retirement Study in the USA and is multidisciplinary in orientation, involving the collection of economic, social, psychological, cognitive, health, biological and genetic data. The original sample was drawn from households that had previously responded to the Health Survey for England (HSE) between 1998 and 2001. A pilot study was conducted in 2001 before main fieldwork began in March 2002. The same group of respondents have been interviewed at two-yearly interviews to measure changes in their health, economic and social circumstances. Younger age groups are replaced or refreshed to retain the panel. The sample has been refreshed using HSE participants in waves 3, 4, 6, 7 and 9. Data are collected using computer-assisted personal interviews and self-completion questionnaires, with additional nurse visits for the assessment of biomarkers every 4 years. The original sample consisted of 11,391 members ranging in age from 50 to 100 years. ELSA is harmonized with ageing studies in other countries to facilitate international comparisons, and is linked to financial and health registry data.

More than 18,000 people have taken part in the study since it started in 2002, with the same people re-interviewed every two years. Data from ELSA participants informs policy across all aspects of ageing including health and social care, retirement and pensions policy, and social and civic participation.