Table 3. Quality assessment of these 13 eligible studies using QUADAS-2.

Study	Risk of bias				Applicability concerns
	Patient selection	Index test	Reference standard	Flow and timing	Patient selection	Index test	Reference standard
Kim [22]	High	Low	Unknown	Unknown	High	Low	Unknown
Mor [23]	High	High	Unknown	Unknown	High	Low	Unknown
Nakae [24]	High	Low	Low	High	High	Low	Unknown
Meinhold-Heerlein [25]	High	Unknown	Unknown	Unknown	High	Low	Unknown
Moore [26]	Low	Low	Low	Low	Low	Low	Low
Visintin [27]	High	High	Low	High	High	Low	Low
Fredriksson [28]	High	High	Unknown	High	High	Low	Unknown
Vrzalova [29]	Unknown	Low	Unknown	Unknown	Unknown	Low	Unknown
Lu [30]	High	High	Unknown	High	High	Low	Unknown
He [31]	Unknown	High	Low	Unknown	Low	Low	Low
Bandiera [32]	Unknown	Low	Unknown	Unknown	Low	Low	Unknown
Moszynski [33]	Low	High	Low	Low	Low	Low	Low
Milivojevic [34]	Unknown	Low	Low	Unknown	Low	Low	Low