Table 1.
Thirty six original articles included in the meta-analysis.
| Year and first author | Ethnicity | Country | Total NO. of PD/controls | NOS |
|---|---|---|---|---|
| 2006Mizuta I (Mizuta et al., 2006) | East Asian | Japan | 882/938 | 7 |
| 2008Mizuta I (Mizuta et al., 2008) | East Asian | Japan | 1403/1941 | 8 |
| 2010Chang XL (Chang et al., 2011) | East Asian | China | 636/510 | 9 |
| 2010Hu FY (Hu et al., 2010) | East Asian | China | 330/300 | 7 |
| 2010Yu L (Yu et al., 2010) | East Asian | China | 332/300 | 8 |
| 2012Gan R(Gan et al., 2012) | East Asian | China | 189/189 | 6 |
| 2012Hu Y (Hu et al., 2012) | East Asian | China | 110/136 | 7 |
| 2012Li NN (Li et al., 2013) | East Asian | China | 685/569 | 7 |
| 2012Miyake Y (Miyake et al., 2012) | East Asian | Japan | 229/357 | 8 |
| 2012Pan F (Pan et al., 2012) | East Asian | China | 403/315 | 7 |
| 2013Liu B (Liu B. et al., 2013) | East Asian | China | 116/95 | 6 |
| 2013Liu J (Liu J. et al., 2013) | East Asian | China | 989/748 | 7 |
| 2013Pan F (Pan et al., 2013) | East Asian | China | 515/450 | 8 |
| 2013Wu-Chou YH (Wu-Chou et al., 2013) | East Asian | China | 633/473 | 8 |
| 2014Guo XY (Guo et al., 2014) | East Asian | China | 1011/721 | 7 |
| 2015Chen YP (Chen et al., 2015) | East Asian | China | 1276/846 | 7 |
| 2015Guo JF (Guo et al., 2015) | East Asian | China | 1061/1066 | 8 |
| 2015Wu GP (Wu et al., 2015) | East Asian | China | 120/100 | 6 |
| 2016Fang J (Fang et al., 2016) | East Asian | China | 583/553 | 8 |
| 2017Chen WJ (Chen et al., 2017) | East Asian | China | 210/251 | 7 |
| 2007Goris A (Goris et al., 2007) | European | UK | 659/2176 | 7 |
| 2007Parsian AJ (Parsian et al., 2007) | European | America | 521/215 | 8 |
| 2007Ross OA (Ross et al., 2007) | European | Ireland | 186/186 | 9 |
| 2007Winkler S (Winkler et al., 2007) | European | Germany | 397/270 | 7 |
| 2008Myhre R (Myhre et al., 2008) | European | Norway | 236/236 | 8 |
| 2008Westerlund M (Westerlund et al., 2008) | European | Sweden | 290/313 | 9 |
| 2009Chung SJ (Chung et al., 2011) | European | America | 1103/1103 | 7 |
| 2009Pankratz N (Pankratz et al., 2009) | European | America | 445/335 | 7 |
| 2010Mata IF (Mata et al., 2010) | European | America | 685/673 | 8 |
| 2011Elbaz A (Elbaz et al., 2011) | European | Multi-country | 5302/4161 | 7 |
| 2012Cardo LF (Cardo et al., 2012) | European | Spain | 1135/772 | 6 |
| 2012Trotta L (Trotta et al., 2012) | European | Italy | 904/891 | 6 |
| 2013Emelyanov A (Emelyanov et al., 2013) | European | Russia | 224/308 | 7 |
| 2017Campêlo CL (Campelo et al., 2017) | Latino | Brazil | 104/98 | 7 |
| 2014Lee PC (Lee et al., 2015) | Mixed | America | 533/700 | 8 |
| 2016Shahmohammadibeni N (Shahmohammadibeni et al., 2016) | West Asian | Iran | 520/520 | 7 |
NO., number; NOS, Newcastle-Ottawa Scale scores.