Cognitive Interventions in Older Persons: Do They Change the Functioning of the Brain?

Table 2

Methodological quality of observational studies.

Observational studies	The healthy elderly	MCI			Dementia
	Nyberg et al. 2003 [30]	Clare et al. 2009 [31]	Hampstead 2011 [32]	Belleville et al. 2011 [33]	Nagaya et al. 2005 [34]	Tanaka et al. 2007 [35]	Spironelli et al. 2013 [36]
Definition study population	0	1	1	1	0	1	1
Selection bias	0	0	0	1	0	0	0
Intervention description and allocation	1	1	1	1	1	1	1
Outcome definition	1	1	1	1	1	1	1
Blinded outcome assessments	0	0	0	1	0	0	0
Completeness dataset/follow-up	0	1	1	1	0	1	1
Loss to follow	0	1	1	1	1	1	1
Confounders	1	0	0	1	0	0	0
Validity and applicability	0	1	0	1	0	0	1
Total	3	6	5	9	3	5	6
CBO classification	C	C	C	B	C	C	C

The CBO classification reflects the level of evidence. A1 is a systematic review of at least two independent randomized double blind studies of sufficient quality and size. A2 is a randomized double blind study of sufficient quality and size. B is a comparative study, which does not meet all the criteria of an A2 study. C is a noncomparative study and D is the opinion of experts (http://www.cbo.nl/).