| First Author | Published Year | Country and area | Mean Age | Cases (n) | Total (n) | Percentage of recorded cases | Research Type |
| Vanderpump M et al. [23] | 1996 | Whickham, UK | 46 | 212 | 664 | 32% | Cohort |
| Althaus B et al. [38] | 1987 | Switzerland | 30.9 | 70 | 116 | 60.3% | CC |
| Dikeman T et al. [48] | 1998 | Netherland | 44 | 10 | 20 | 50% | CC |
| Shapiro L et al. [49] | 1997 | USA | 43.2 | 17 | 34 | 50% | CC |
| Mercuro G et al. [50] | 2000 | Cagliari, Italy | 41.3 | 19 | 38 | 50% | CC |
| Biondi B et al. [51] | 1999 | Naples, Italy | 36 | 26 | 56 | 46.4% | CS |
| Nystrom E et al. [52] | 1988 | Sweden | 61.5 | 20 | 37 | 54% | CS |
| Hak A E et al. [53] | 2000 | Netherland | 54.5 | 124 | 1055 | 11.7% | Cohort |
| Parle J V et al. [54] | 2001 | UK | 70 | 386 | 1191 | 32.4% | Cohort |
| Walsh J P et al. [55] | 2005 | Australia | 49.6 | 158 | 2064 | 7.6% | CS |
| Luboshitzky R et al. [56] | 2002 | Nepal | 44.1 | 57 | 91 | 62.6% | CC |
| Bauer D C et al. [57] | 2007 | USA | 64.6 | 36 | 480 | 7.5% | |
| Total | 2152 | 7591 | 28.3% |