Table 1.

QUADAS-2 bias analysis

	Risk of Bias				Applicability Concerns
Study	Patient Selection	Index Test	Reference Standard	Flow and Timing	Patient Selection	Index Test	Reference Standard
Kiesel et al15	U	L	U	U	L	U	H
Kiesel et al16	H	U	L	U	L	U	L
Chorba et al3	L	L	L	U	L	L	L
Peate et al28	U	U	U	U	L	U	U
Butler et al2	L	U	L	U	L	U	U
O’Connor et al25	L	L	L	U	L	L	L
Shojaedin et al32	H	U	H	U	L	U	H

H, high risk; L, low risk; U, unclear risk.