Table 3.

Model statistics for primary analysis

Primary model statistics
PACC-3 ˜ Covariates + Group + Age + Group × Age + random slope + random intercept
Variable	β	95% CI	P
Covariates
Intercept	−3.44	−4.60, −2.29	0.42
Female	0.45	0.25, 0.64	<0.0001
WRAT III	0.03	0.02, 0.04	<0.0001
Practice	0.07	0.03, 0.10	0.0020
Predictors of interest
Age	−0.03	−0.05, −0.02	<0.0001
Group			0.24
Group 2	−0.14	−0.74, 0.46
Group 3	0.22	−0.06, 0.50
Group 4	0.39	0.04, 0.74
Age × Group			<0.0001
Age × Group 2	−0.01	−0.05, 0.03
Age × Group 3	−0.01	−0.03, 0.01
Age × Group 4	−0.11	−0.13, −0.08
Age × Group details Simple PACC-3 slopes
Group	β (SE)		95% CI
Group 1: A−T−	−0.032 (0.008)		−0.047, −0.017
Group 2: A−T+	−0.041 (0.021)		−0.082, −0.0001
Group 3: A+T−	−0.041 (0.012)		−0.064, −0.017
Group 4: A+T+	−0.140 (0.015)		−0.168, −0.111
Group contrasts between PACC-3 slopes
Contrast	β (SE)		P a
A−T− minus A−T+	0.009 (0.020)		0.97
A−T− minus A+T−	0.009 (0.011)		0.83
A−T− minus A+T+	0.108 (0.014)		<0.0001
A−T+ minus A+T−	−0.0001 (0.022)		1.00
A−T+ minus A+T+	0.099 (0.024)		0.0002
A+T− minus A+T+	0.099 (0.016)		<0.0001

Model statistics for primary analysis linear mixed effects model investigating the association between biomarker groups and retrospective cognition (i.e. PACC-3). Parameter estimates, 95% confidence intervals (CI) and P-values are shown for the main model covariates, age, group and the interaction of group × age (top half of table) with the A−T− group (i.e. group 1) as the contrast group. The significant group × age effect indicates group level differences in longitudinal retrospective PACC-3 trajectories. A breakdown of the details of the group × age interaction shows the estimate, standard error (SE) and 95% CI of the simple PACC-3 slopes for each biomarker group, and the Tukey adjusted post hoc comparisons of biomarker group slopes (bottom half of table).

WRAT-III = Wide Range Achievement Test – third edition.

^aTukey-adjusted significance for family of four.