Table 2.

Types of primary outcome measures used in all included randomised controlled trials

Primary outcome measure	Frequency of use of primary outcome measure in randomised controlled trials in:
	Alzheimer’s disease (n = 83)		Parkinson’s disease (n = 44)
	n	%	n	%
Clinical outcome measure only	62	75	24	55
Clinical outcome measure and biomarker	6	7	4	9
Clinical outcome measure and time-to-event outcome	1	1	0	0
Biomarker only	12	15	5	11
Time-to-event outcome only	2	2	11	25

There was insufficient information available about one unpublished trial’s [42] outcome measures to allow its classification