Social Activity and Cognitive Functioning Over Time: A Coordinated Analysis of Four Longitudinal Studies

Table 4

VLS participant characteristics.

	Year of testing
Measure	Baseline; (𝑛=977)	Year 3; (𝑛=723)	Year 6; (𝑛=571)	Year 9; (𝑛=411)	Year 12; (𝑛=275)	Year 15; (𝑛=91)	Year 18; (𝑛=52)
	M (SD)	M (SD)	M (SD)	M (SD)	M (SD)	M (SD)	M (SD)
Retention from previous testing (%)^a	—	74	79	72	67	79	57
Age	68.6 (6.7)	71.3 (6.6)	73.7 (6.4)	76.5 (5.9)	79.3 (5.2)	82.2 (4.6)	85.1 (3.6)
Years of education at baseline	14.9 (3.3)	15.4 (3.2)	15.6 (3.1)	15.9 (3.1)	15.8 (3.1)	15.2 (3.1)	14.8 (2.8)
Sex, female [𝑛 (%)]	614 (62.8)	450 (62.2)	346 (60.6)	251 (61.1)	170 (61.8)	60 (65.9)	35 (67.3)
Reasoning^b	11.2 (4.7)	11.7 (4.2)	10.3 (4.7)	10.3 (4.6)	9.9 (4.6)	7.5 (4.7)	6.5 (4.2)
Fluency	17.7 (4.3)	17.9 (4.4)	17.7 (4.5)	17.2 (4.8)	16.3 (4.9)	14.7 (5.8)	13.8 (5.4)
Memory^c	13.7 (5.9)	14.7 (6.0)	14.7 (6.1)	14.9 (6.4)	11.7 (5.4)	13.0 (6.3)	—
Semantic knowledge	43.7 (7.4)	44.7 (6.2)	44.3 (6.0)	44.2 (5.8)	43.5 (5.7)	42.7 (7.1)	42.6 (6.6)
Social activity	23.0 (6.9)	23.2 (7.2)	22.8 (7.3)	22.5 (7.2)	21.2 (7.1)	22.8 (7.7)	21.1 (7.2)
Social activity change	—	−0.1 (5.4)	−0.3 (6.0)	−0.9 (6.4)	−2.5 (6.9)	−3.5 (7.5)	−5.3 (8.1)

M: mean, SD: standard deviation. The range for each measure with a defined upper limit is as follows: reasoning = 0–20, Memory = 0−30, and Semantic knowledge 0−54.
^aThe 1986 cohort was followed for up to 18 years, the 1993 cohort for up to 12.
^bThe reasoning measure was not given until year 6 for the 1986 cohort.
^cThe memory measure was not given in year 18.