TABLE 2.

Quality assessment^a

Study	Risk of bias based on internal validation				Applicability concerns based on external validation
	Patient selection	Index test	Reference test	Flow and timing	Patient selection	Index test	Reference test
Wouthuyzen-Bakker et al. (24)	LR	LR	HR	LR	LR	LR	LR
Pérez-Prieto et al. (20)	LR	LR	HR	LR	LR	LR	LR
Bedenčič et al. (22)	LR	LR	LR	LR	LR	LR	LR
Al-Mayahi et al. (3)	LR	?	HR	LR	HR	LR	LR
Tetreault et al. (21)	LR	HR	LR	LR	?	LR	LR
Burnett et al. (19)	LR	HR	LR	LR	?	LR	LR
Ghanem et al. (23)	HR	HR	LR	LR	?	LR	LR

^aQuality assessment of the included studies (3, 19–24) using the QUADAS-2 tool for diagnostic studies (29). Specific details on internal and external validation are described in Materials and Methods. LR, low risk; HR, high risk; ?, unclear risk.