Table 1.

Longitudinal study design showing birth cohorts of the study from 1946 to 1996 with measurements at 5-year intervals^a.

Birth cohort	Age at T1 2016-2021	Age at T2 2021-2026	Age at T3 2026-2031	Age at T4 2031-2036
1996	20 years	25 years	30 years	35 years
1946	70 years	75 years	80 years	85 years
n	600	480	384	307

^aThe ages of the youngest (20 years old at baseline) and oldest (70 years old at baseline) cohorts and the expected number of subjects at 4 test points (T1 to T4) are indicated.