Table 1.

The Glostrup 1914 Cohort: sample descriptives at ages 75, 80, and 85.

	Age 75 (N = 401)	Age 80 (N = 344)	Age 85 (N = 156)
Sex (% male)	48.4	48.0	40.4
Education	3.5 (1.4)	3.5 (1.4)	3.6 (1.4)
Social class	6.5 (1.0)	6.3 (1.0)	6.3 (1.0)
Leisure activity	29.6 (7.5)	30.2 (7.8)	26.0 (8.0)
Digit span	9.8 (1.8)	9.1 (1.4)	8.8 (1.5)
Digit symbol	33.9 (1.3)	31.2 (1.3)	25.0 (1.2)

For descriptive purposes, sample size was determined by the presence of at least one of the cognitive variables at any given age. Education was an overall score combining school education on a 3-point scale (primary to upper secondary) and vocational training on a 5-point scale (no vocational training to academic). Higher scores represent more education/training. Social class was coded according to Svalastoga (1959), producing six categories labeled strata three (most professional) to eight (unskilled occupations). Leisure activity was the sum of the 11 activity items described in the principal components analysis (PCA). For leisure activity and cognitive ability, the data in the table represent data from participants with complete data across all three waves for illustrative purposes, though the modeling approach included participants with data at any wave.