Table 2.
General characteristics of the selected studies.
| Author/year/place | Study design | Level of evidence | Sample | Follow-up period |
|---|---|---|---|---|
| (Gul et al., 2005)7 Malaysia |
Cross-sectional | VI | 419 | January to May 2002 |
| (Colgan et al., 2005)9 Australia |
Retrospective cohort | IV | 420 | August/2011–July/2002 |
| (Askarian et al., 2006)10 Iran |
Prospective cohort | IV | 1000 | February to July/2004 |
| (Castella et al., 2006)11 Italy |
Cross-sectional | VI | 803 | October to November/2003 |
| (Bull et al., 2006)12 Australia |
Retrospective cohort | IV | 10,643 | January/2003–September/2004 |
| (Fennessy et al., 2006)13 Ireland |
Prospective cohort | IV | 131 | 2004 |
| (Sae-Tia and Chongsomchai, 2006)14 Thailand |
Prospective cohort | IV | 250 | August 2004–February/2005 |
| (Malavaud et al., 2008a)15 France |
Cross-sectional | VI | 84 | 2005 |
| (Tourmousoglou et al., 2008)6 Greece |
Prospective cohort | IV | 890 | January to October/2000 |
| (Malavaud et al., 2008b)16 France |
Cross-sectional | VI | 100 | July to December/2006 |
| (Mahdaviazad, 2011)17 Iran |
Cross-sectional | VI | 365 | April to September/2010 |
| (Meeks et al., 2011)18 United States |
Retrospective cohort | IV | 517 | July/2006–December/2007 |
| (Durando et al., 2012)19 Italy |
Prospective cohort | IV | 717 | November 15 to December 15/2007 |
| (Hohmann et al., 2012)20 Germany |
Prospective cohort | IV | 5064 | June/2008 to April/2009 |
| (Pittalis et al., 2013)21 Italy |
Prospective cohort | IV | 2835 | April to June/2008 |
| (Machado-Alba et al., 2013)22 Colombia |
Cross-sectional | VI | 211 | April 1st to June 30/2010 |
| (Napolitano et al., 2013)23 Italy |
Cross-sectional | VI | 382 | October/2009 to January/2012 |
| (Wright et al., 2013)24 United States |
Cross-sectional | VI | 545,322 | 2003–2010 |