Table 3 Methodological quality
Author | Selection Representativeness (maximum: one star) | Selection Selection (maximum: one star) | Selection Ascertainment (maximum: one star) | Selection Outcome of interest (maximum: one star) | Comparability Comparability (maximum: two stars) | Outcome Assessment of outcome (maximum: one star) | Outcome Duration of follow-up (maximum: one star) | Outcome Adequacy of follow-up (maximum: one star) | Total Score (maximum: 9 stars) |
|---|---|---|---|---|---|---|---|---|---|
Intrathoracic | |||||||||
 Griffin 2001 [18] | 0 | NA | 0 | * | NA | 0 | NA | NA | 1 |
 Holscher 2003 [19] | * | NA | * | * | NA | 0 | NA | NA | 3 |
 Hunerbein 2004 [21] | * | NA | * | * | NA | 0 | * | * | 5 |
 Kauer 2008 [23] | * | NA | 0 | * | NA | * | NA | NA | 3 |
 Tuebergen 2008 [31] | 0 | NA | * | * | NA | * | * | * | 5 |
 Qin 2010 [29] | 0 | NA | * | * | NA | * | NA | NA | 3 |
 Hu 2011 [20] | * | NA | * | * | ** | 0 | NA | NA | 5 |
 Jiang 2011 [22] | * | NA | * | * | * | 0 | * | * | 6 |
 Yin 2012 [33] | 0 | NA | * | * | NA | 0 | * | * | 4 |
 Al-Issa 2014 [15] | 0 | NA | * | * | NA | * | NA | NA | 3 |
 Bludau 2014 [17] | * | NA | 0 | * | NA | * | 0 | * | 4 |
 Shuto 2017 [30] | 0 | NA | * | * | NA | * | 0 | * | 4 |
Cervical | |||||||||
 Orringer 1986 [28] | 0 | NA | 0 | * | NA | 0 | * | * | 3 |
 Bhasin 2000 [16] | 0 | NA | * | * | NA | * | 0 | * | 4 |
 Korst 2005 [24] | * | NA | 0 | * | NA | * | NA | NA | 3 |
 Lindeman 2008 [27] | 0 | NA | * | * | NA | 0 | 0 | 0 | 2 |
 Larburu 2013 [25] | * | NA | * | * | NA | 0 | NA | * | 4 |
 Leenders 2013 [26] | 0 | NA | 0 | * | NA | 0 | NA | NA | 1 |
 Van Rossum 2017 [32] | * | NA | * | * | NA | 0 | * | * | 5 |