Table 2.

Potential risk of bias and applicability of the three diagnostic accuracy studies

	Risk of bias				Applicability
Study	Patient selection	Index test	References standard	Flow and timing	Patient selection	Index test	References standard
Li (2008)	J	?	?	L	J	J	J
Sun (2012)	J	J	?	L	J	J	J
Zhou (2015)	J	L	?	L	J	L	J

J: low risk; L: high risk; ?: unclear risk.