Table 2. The Newcastle-Ottawa Assessment scale for included nonrandomized trials.
Study Selection Comparability of Cases and Control Outcome
Case
Definition
Adequacy
Repres1
of Case
Selection
of
Controls
Definition
of
Controls
Asc 2
of
Exposure
Same Method
of
Asc 2 for Cases and
Controls
Nonresponse
Rate
Total
Alentorn-Geli, 2010 ⋆ ⋆ ⋆ ⋆ ⋆ ⋆ 6
Azboy, 2014 ⋆ ⋆ ⋆ ⋆ ⋆ ⋆ ⋆ ⋆ 8
Cury, 2017 ⋆ ⋆ ⋆ ⋆ ⋆ ⋆ 6
de Abreu, 2014 ⋆ ⋆ ⋆ ⋆ ⋆ ⋆ ⋆ 7
Franceschi, 2013 ⋆ ⋆ ⋆ ⋆ ⋆ ⋆ 6
Kim, 2011 ⋆ ⋆ ⋆ ⋆ ⋆ ⋆ 6
Lee, 2014 ⋆ ⋆ ⋆ ⋆ ⋆ ⋆ ⋆ 7
Metso, 2020 ⋆ ⋆ ⋆ ⋆ ⋆ ⋆ ⋆ 7
Ozer, 2018 ⋆ ⋆ ⋆ ⋆ ⋆ ⋆ 6
Pande, 2017 ⋆ ⋆ ⋆ ⋆ ⋆ ⋆ ⋆ 7
Razazadeh, 2016 ⋆ ⋆ ⋆ ⋆ ⋆ ⋆ ⋆ ⋆ 8
Sohn, 2014 ⋆ ⋆ ⋆ ⋆ ⋆ ⋆ 6
Sukur, 2016 ⋆ ⋆ ⋆ ⋆ ⋆ ⋆ ⋆ ⋆ 8
Taşdemir, 2015 ⋆ ⋆ ⋆ ⋆ ⋆ ⋆ ⋆ 7
Wei, 2014 ⋆ ⋆ ⋆ ⋆ ⋆ ⋆ 6
Zehir, 2015 ⋆ ⋆ ⋆ ⋆ ⋆ ⋆ ⋆ 7
1 Repres = Representativenes;2 Asc = Ascertainment