| Author | Year | Prevalence % | Ethnic group |
| Yu et al. | 1996 | 19.0 | Caucasian American |
| Sarin et al. | 1999 | 31.3 | Caucasian America |
| Raheem et al. | 2007 | 9.1 | Caucasian Irish |
| Tim et al. | 2010 | 3.1 | Caucasian Brazilian |
| Phukubye and Oyedele | 2011 | 23.5 | Caucasian and African |
| Piyawinijwong et al. | 2012 | 50.5 | Asian Thailand |
| Tabira et al. | 2012 | 68.6 | Asian Japanese |
| Zeng et al. | 2012 | 86.9 | Asian Chinese |
| Chew et al. | 2014 | 31.25 | Asian, Singapore |
| O.F. Egerci et al | 2016 | 22.8 | Caucasian Turkish |