Table 4.

Results of Mixed-Effects Models Examining Differences in Age-Associated Cognitive Slope by Birth Cohorts: Executive Functions (Letter Fluency P and S) as Outcome

	Model 1			Model 2
	Coefficient	SE	p Value	Coefficient	SE	p Value
Intercept	.37	0.08	<.0001	.51	0.08	<.0001
Female	.17	0.03	<.0001	.17	0.03	<.0001
Age	.003	0.007	.65	.004	0.007	.54
Second assessment	.02	0.04	.65	.02	0.04	.57
Third assessment	.08	0.05	.08	.08	0.05	.07
Second assessment × MYHAT	−.005	0.04	.88	−.01	0.04	.78
Third assessment × MYHAT	−.05	0.04	.15	−.06	0.04	.12
Cohort 1902–1911	−.85	0.09	<.0001	−.57	0.09	<.0001
Cohort 1912–1921	−.66	0.08	<.0001	−.48	0.08	<.0001
Cohort 1922–1931	−.43	0.08	<.0001	−.38	0.08	<.0001
Age × Cohort 1902–1911	−.05	0.009	<.0001	−.05	0.009	<.0001
Age × Cohort 1912–1921	−.02	0.008	.004	−.02	0.008	.005
Age × Cohort 1922–1931	−.01	0.008	.11	−.01	0.008	.08
Second assessment × Cohort 1902–1911	.009	0.06	.88	.0005	0.06	.99
Second assessment × Cohort 1912–1921	−.007	0.04	.87	−.01	0.04	.77
Second assessment × Cohort 1922–1931	−.02	0.03	.53	−.02	0.03	.50
Third assessment × Cohort 1902–1911	−.06	0.06	.34	−.06	0.06	.29
Third assessment × Cohort 1912–1921	−.03	0.04	.51	−.03	0.04	.46
Third assessment × Cohort 1922–1931	−.03	0.03	.43	−.03	0.03	.42
Education
<High school				−.64	0.04	<.0001
=High school				−.20	0.04	<.0001
Age × Education (<high school)				−.006	0.004	.15
Age × Education (=high school)				.0007	0.004	.86

Notes: Reference groups: male; Cohort 1932–1943; Age × Cohort 1932–1943; Age × Education (>high school). Age variable was centered at age 80 (ie, age at each assessment −80). Age and intercept are treated as random effects. Second and third assessments refer to the practice (assessment) effects at the second and third assessments. MYHAT = Monongahela-Youghiogheny Healthy Aging Team study.