Table 1.
Main characteristics of the included studies
| Study, year | Country | No. of Subjects | Gender (M/F) | Median/Mean age (years) | Age range (years) | Design | Inclusion interval | QUADAS scores |
|---|---|---|---|---|---|---|---|---|
| Kole,1998 [13] | Netherlands | 5 | 3/2 | 20/20.2 | 17–24 | Retrospective | NR | 13 |
| Schulte,1999 [14] | Germany | 27 | 17/10 | 17/NR | 5–36 | Prospective | Jan.1993-NR | 11 |
| Franzius,2000 [15] | Germany | 32 | NR | NR | NR | Retrospective | Aug.1995-Jun.1999 | 11 |
| Schulte,2000 [16] | Germany | 44 | NR | NR | NR | Retrospective | Jan.1993-NR | 12 |
| Franzius,2001 [17] | Germany | 32 | NR | NR | NR | Retrospective | Aug.1995-Jun.1999 | 11 |
| Franzius,2002 [18] | Germany | 6 | NR | NR | NR | Retrospective | NR | 11 |
| Yanagawa,2003 [19] | Japan | 5 | 4/1 | 14/14.4 | 11–20 | Prospective | Jun.1999-Mar.2000 | 13 |
| Kneisl,2006 [20] | USA | 38 | NR | NR | NR | Retrospective | Dec.1994-Nov.2004 | 13 |
| Iagaru,2006 [21] | USA | 6 | NR | NR | NR | Retrospective | Jan.2003-Dec.2005 | 12 |
| Volker,2007 [22] | Germany | 11 | NR | NR | 1–18 | Prospective | Dec.2003-Oct.2006 | 9 |
| Shin,2008 [23] | South Korea | 7 | NR | NR | 6–79 | Retrospective | May.2004-Jun.2007 | 12 |
| Charest,2009 [24] | Canada | 24 | NR | NR | NR | Retrospective | May.2004-Apr.2008 | 12 |
| Hawkins,2009 [25] | USA | 40 | NR | 15.1/NR | 7.1–31 | Prospective | Jul.1995-Aug.2004 | 11 |
| Benz,2010 [26] | USA | 6 | 2/4 | 27/30.8 | 18–58 | Prospective | Feb.2005-Nov.2007 | 13 |
| Lindholm,2011 [27] | Finland | 6 | 4/2 | 16.5/16.5 | 15–18 | Prospective | NR | 13 |
| Bandopadhyaya,2012 [30] | India | 22 | 14/8 | 21.55/NR | 8–66 | Prospective | NR | 13 |
| Cistaro,2012 [28] | Italy | 11 | NR | NR/14 | NR | NR | NR | 13 |
| Ozkan,2012 [29] | Turkey | 7 | 6/1 | 25/26.1 | 18–50 | Retrospective | 2007–2009 | 11 |
| Bai,2013 [33] | China | 14 | 9/5 | NR/14.9 | 8–22 | Retrospective | Jan.2009-Nov.2011 | 13 |
| Byun,2013 [31] | South Korea | 206 | 127/79 | 15/NR | 4–71 | Retrospective | Jan.2006-Nov.2011 | 11 |
| Kong,2013 [32] | South Korea | 26 | 16/10 | NR/21 | 9–55 | Prospective | May.2010-Aug.2011 | 12 |
| Chang,2015 [35] | South Korea | 109 | 74/35 | NR/17 | NR | Retrospective | Feb.2002-Sep.2012 | 11 |
| Quartuccio,2015 [34] | Italy | 20 | 10/10 | 15.5/NR | NR | Retrospective | Jan.2006-Sep.2010 | 11 |
| Hurley, 2016 [36] | USA | 39 | 19/20 | Median 12 | 5–19 | Retrospective | 2003–2012 | 13 |
| Angelini, 2017 [38] | Italy | 37 | 20/17 | Mean 20 | 7–52 | Retrospective | 2008–2014 | 13 |
| Sharp, 2017 [37] | USA | 8 | 5/3 | Median 13 | 8–16 | Retrospective | Oct.2004-Feb. 2013 | 13 |
M male, F female, NR not reported