. Author manuscript; available in PMC: 2017 Oct 23.

Published in final edited form as: J Prev Alzheimers Dis. 2017 Apr 25;4(2):109–115. doi: 10.14283/jpad.2017.12

Table 2.

Approach to levels of clinical and biomarker evidence in support of disease modification

Population	Level of Evidence	Clinical Design	Clinical Outcome	Biomarker Data
Mild-Moderate AD	A1	Delayed start or delayed withdrawal	Significant effect on cognitive and functional or global measures	Significant effects on several independent biomarkers
	A2	Parallel group	Significant effect on cognitive and functional or global measures	Significant effects on several related biomarkers
	B1	Delayed start or delayed withdrawal	Significant effect on cognitive and functional measures	Significant effects on one biomarker or biomarkers limited to one aspect of AD
	B2	Parallel group	Significant effect on cognitive and functional measures	Significant effects on one biomarker or biomarkers limited to one aspect of AD
	C1	Parallel group	Trend on cognitive and functional measures	Significant effects on several independent biomarkers
	C2	Parallel group	Trend on cognitive and functional measures	Significant effects on one biomarker or biomarkers limited to one aspect of AD