A Meta-Analysis of the Influencing Factors for Tracheostomy after Cervical Spinal Cord Injury

Table 2

Literature quality of the included studies.

First author	Selection				Comparability	Exposure			Total score
	I	II	III	IV	V	VI	VII	VIII
Lee DS [11]	1	1	1	1	2	1	1	1	9
Tanaka J [20]	1	1	1	1	2	1	1	NA	8
Tang H [23]	1	1	1	1	2	1	1	NA	8
Shi TZ [19]	1	1	1	1	2	1	1	NA	8
Childs BR [22]	1	1	1	1	2	1	1	1	9
Quesnel A [17]	1	1	1	1	2	1	1	NA	8
Hou YF [9]	1	1	1	1	2	1	1	NA	8
McCully BH [14]	1	1	1	1	2	1	1	NA	8
Menaker J [15]	1	1	1	1	2	1	1	NA	8
Nakashima H [16]	1	1	1	1	2	1	1	NA	8
Leelapattana P [12]	1	1	1	1	2	1	1	NA	8
Yugue I [21]	1	1	1	1	2	1	1	1	9
Branco BC [8]	1	1	1	1	2	1	1	1	9
Ji YH [10]	1	1	1	1	2	1	1	NA	9
Li Q [13]	1	1	1	1	2	1	1	NA	8
Shao J [18]	NA	1	1	1	2	1	1	NA	7

Note: I: is the case definition adequate?; II: representativeness of the cases; III: selection of controls; IV: definition of controls; V: comparability of cases and controls on the basis of the design or analysis; VI: ascertainment of exposure; VII: same ascertainment method for cases and controls; VIII: nonresponse rate; NA: not available.