Table 2.

Comparison of the demographic and clinical characteristics of amyloid-positive and amyloid-negative patients

	Npatients	Nsites	Estimate [95%CI]	p	Marginal means [95%CI]
					Aβ-negative	Aβ-positive
Age at symptom onset	644	28	−1.322 [−3.130, 0.477]	0.15	60.4 [58.4, 62.4]	59.1 [57.8, 60.4]
Age at diagnosis	671	30	−1.415 [−3.18, 0.348]	0.12	63.9 [62.0, 65.8]	62.5 [61.4, 63.6]
MMSE at diagnosis	596	28	−0.059 [−1.350, 1.290]	0.93	20.8 [19.5, 22.2]	20.7 [19.9, 21.6]
CDR at diagnosis (%CDR≥1)	413	21	0.118 [−0.573, 0.818]	0.74	61% [42, 77]	58% [46, 70]
Sex (% Women)	689	30	0.406 [−0.058, 0.867]	0.085	53% [42, 63]	63% [59, 67]
APOE (% e4 carriers)	342	22	0.089 [−0.639, 0.818]	0.81	45% [29, 62]	47.5% [40, 55]
PCA diagnosis (% PCA pure)	625	29	1.506 [0.769, 2.26]	<0.0001	81% [56, 94]	95% [86, 98]
MRI (% posterior atrophy)	543	27	0.226 [−0.605, 1.060]	0.59	92% [78, 97]	94% [85, 97]
FDG-PET (% post. hypometabolism)	324	22	0.578 [−0.896, 2.05]	0.44	97% [84, 99]	98% [94, 99]

For each variable, a separate linear mixed model (continuous outcomes) or generalized mixed effect model (binary outcomes) was run, using amyloid status as a fixed effect and site as a random effect. Estimate 95%CI were obtained using the likelihood profile method. Number of participants and sites with available data varies from one variable to the other. Aβ-positive patients included those who received a positive result on CSFAβ42 and/or amyloid-PET, and Aβ-negative patients received negative results from CSF or PET. This sample included 390 with CSF only, 153 with PET only, and 146 with both; in this subgroup 27 patients had discrepant results (3 CSF+/PET-, 24 CSF-/PET+) and were included in the amyloid-positive group.