Table 1 Characteristics of included studies in the present systematic review and meta-analysis. −, not reported
First author | Year | Study period | Country | Geographical region | Study size | Males | Females |
|---|---|---|---|---|---|---|---|
Calao | 2018 | 2015–2016 | Australia | Asia-Pacific | 11,433 | 5616 | 5817 |
Cosmatos | 2013 | 2007 | USA | USA | 15,054,519 | 7,233,818 | 7,820,701 |
Delaney | 2017 | 2015 | Ireland | Europe | 15,547 | 15,476 | 15,476 |
Garg | 2017 | 1999–2016 | USA | USA | 45,855,960 | 20,832,510 | 25,023,450 |
Ianhez | 2018 | 2017 | Brazil | South America | 17,004 | – | – |
Ingram | 2017 | 2013 | UK | Europe | 4,364,308 | – | – |
Jemec | 1996 | 1992–1993, 1994–1995 | Denmark | Europe | 585 | 276 | 231 |
Lee | 2018 | 2007–2016 | Korea | Asia-Pacific | 51,103,943 | 25,573,939 | 25,576,389 |
Lookingbill | 1988 | 1985–1986 | USA | USA | 1106 | – | – |
Reeder | 2014 | 2011–2012 | USA | USA | 8480 | – | – |
Revuz | 2008 | 2005 | France | Europe | 6887 | – | – |
Richard | 2018 | 2016 | France | Europe | 20,012 | 9760 | 10,252 |
Riis | 2018 | 1995–2015 | Denmark | Europe | 27,765 | 14,558 | 12,238 |
Santos | 2017 | 2000–2014 | Portugal | South America | 1,569,333 | – | – |
Shahi | 2014 | 1968–2008 | USA | USA | 139,280 | 65,649 | 71,240 |
Sung | 2013 | 2007–2011 | USA | USA | 563,931 | – | – |