Table 2.

Methodological quality of studies included in the meta-analysis using Newcastle–Ottawa Methodological Quality Scale

Studies	Respersentativive of the exposed cohort	Selection of the non-exposed cohort	Ascertainment of exposure	Demonstration that outcome was not present at study start	Comparability of cohorts based on design or analysis	Assessment of outcome	Enough follow up period (>1 year	Adequacy of follow up	Overall NOS
Trooyen et al., 2001[12]	1	1	1	1	1	1			6
James et al., 2000[9]	1	1	1	1	1	1		1	7
Guerrero-peral et al., 2002[23]	1	1	1	1	1	1			6
Maliszewska et al., 2005[21]	1	1	1	1	1	1		1	7
Di Angelantonio et al., 2005[7]	1	1	1	1	1	1	1	1	8
Jensen et al., 2007[14]	1	1	1	1	1	1	1		7
Barber et al., 2007[25]	1	1	1	1	1	1		1	7
Scheitz et al., 2012[17]	1	1	1	1	1	1	1		7
Hajdinjak et al., 2012[22]	1	1	1	1	1	1			6
Jensen et al., 2012[15]	1	1	1	1	1	1	1		7
Scheitz et al., 2014[16]	1	1	1	1	1	1			6
Faiz et al., 2014[8]	1	1	1	1	1	1			6
Lasek -Bal et al., 2014[20]	1	1	1	1	1	1			6
Maoz et al., 2015[18]	1	1	1	1	1	1			6
Peddada et al., 2016[26]	1	1	1	1	1	1			6
Su et al., 2016[24]	1	1	1	1	1	1			6
Batal et al., 2016[27]	1	1	1	1	1	1	1		7
Sung et al., 2017[19]	1	1	1	1	1	1	1	1	8
Sui et al., 2019[13]	1	1	1	1	1	1		1	7

NOS: Newcastle–Ottawa Scale