Cohort profile: The Danish Longitudinal Study of Ageing (DLSA)

The Danish Longitudinal Study of Ageing in a nutshell

• The Danish Longitudinal Study of Ageing (DLSA) is a representative prospective cohort study of older adults living in Denmark, aged 52years and above.

• The study commenced in 1997, and the baseline sample is followed up every 5 years.

• The original sample consisted of 8390 adults, randomly sampled from six cohorts (born 1920, 1925, 1930, 1935, 1940 and 1945), and had an initial field response rate at 70.3%, resulting in 5864 completed and partial interviews with respondents aged 52 to 77years.

• A new cohort of 52-year olds is added in every wave, along with refreshment samples to replace those lost to attrition.

• To date, five waves have been collected (1997, 2002, 2007, 2012 and 2017), and the longitudinal database contains 43 731 interviews with 18 914 unique respondents from 10 cohorts.

• A panel consisting of 11 995 respondents have participated in at least two waves and can be used for dynamic analyses.

• The survey dataset is openly available to researchers shortly after collection.