Table 2.

QUADAS-2 scale of diagnosis studies.

study	Risk of bias				Applicability
	Patient selection	Index tests	Reference standard	Appropriate interval	Patient selection	Index tests	Reference standard
Hanqing Wu	☺	☺	☺	?	☺	☺	☺
Yun Chen	?	?	☺	?	☺	☺	☺
Xu Han	?	?	☺	☹	☺	☺	☺
Lu Hong	?	☺	☺	☹	☺	☺	☺
Kaiwei Xu	☺	☺	☺	☹	☺	☺	☺
Xianbo Shen	☺	☺	☺	☹	☺	☺	☺
Hongxian Yan	☺	☺	☺	?	☺	☺	☺
Siqiao Li	?	?	☺	?	☺	☺	☺
Fan Yang	☺	☺	☺	☹	☺	☺	☺