Table 2.

Levels of evidence for the overall quality of the measurement property [16]

Level	Rating	Criteria
strong	+++ or ---	Consistent findings in multiple studies of good
		methodological quality OR in one study of excellent
		methodological quality
moderate	++ or --	Consistent findings in multiple studies of fair
		methodological quality OR in one study of good
		methodological quality
limited	+ or -	One study of fair methodological quality
conflicting	+/-	Conflicting findings
unknown	?	Only studies of poor methodological quality

[..] = reference number

+ = positive result, - = negative result