Table 9. Identified data characteristics in the included studies.

Variable Category	Variable Subcategory	Number of Studies	Featuring Studies
Neuroimaging: 28 ML studies	MRI	27	[24–26, 28, 31–37, 39–46, 48–53, 61, 62]
	PET	8	[27, 28, 33, 35, 45, 50–52]
Cognitive Measures: 5 ML studies, 1 MS study	MMSE	2	[34, 65]
	ADAS-cog	2	[38, 56]
	Other (CDR, FAQ, Buschke Cued Recall)	3	[32, 57, 65]
Genetic: 5 ML studies	ApoE	5	[33, 38, 41, 44, 45]
	Family History	1	[41]
Lab Test: 10 ML studies	CSF	8	[28, 30, 32, 33, 35, 45, 45, 51]
	Other Lab tests	4	[38, 44, 45, 47]
Demographic: 5 ML studies, 2 MS studies	Age	4	[30, 40, 53, 65]
	Other demographic	3	[38, 71, 72]

Abbreviations: MRI: Magnetic Resonance Imaging; PET: Positron Emission Tomography; MMSE: Mini Mental State Examination; ADAS-cog: Alzheimer's Disease Assessment Scale-cognitive subscale; CDR: Clinical Dementia Rating; FAQ: Functional Activities Questionnaire; CSF: Cerebrospinal Fluid