1. Contacted authors.
| Study | Contact author | Contact email | Reply/did not reply |
| Ahmed 2014 | Mohammed G | dr_ghada77@hotmail.com | Did not reply |
| Asilian 2011 | Salimi E | s_salimi@resedent.mui.ac.ir | Did not reply |
| Bernstein 2001 | Bernstein EF | dermguy@hotmail.com | Did not reply |
| Chae 2015 | Choi YS | uuhderma@hanmail.net | Responded |
| Cho 2010 | Kim DH | terios92@hanmail.net | Did not reply |
| Gadkari 2014 | Gadkari R | drreshmagadkari@gmail.com | Did not reply |
| Hedelund 2010 | Hedelund L | lene.hedelund@hotmail.com | Did not reply |
| Hedelund 2012 | Hedelund L | lenhed@rm.dk | Did not reply |
| Karnik 2014 | Smith SR | ssmith@stacyrsmithmd.com | Did not reply |
| Kim 2009 | Lee JH | juhee@yuhs.ac | Did not reply |
| Kim 2009a | Kim S | i4ks@yahoo.com | Did not reply |
| Lee 2009 | Suh DH | daehun@snu.ac.kr | Did not reply |
| Lee 2011 | Kim BJ | beomjoon@unitel.co.kr | Did not reply |
| Linkner 2014 | Linkner RV | Rita.Linkner@mountsinai.org | Did not reply |
| Manuskiatti 2013 | Manuskiatti W | woraphong.man@mahidol.ac.th | Did not reply |
| Min 2009 | Suh DH | daehun@snu.ac.kr | Did not reply |
| Mohammed 2013 | Mohammed G | dr_ghada77@hotmail.com | Did not reply |
| Munavalli 2013 | Munavalli GS | gmunavalli@carolinaskin.com | Did not reply |
| Nofal 2014 | Nofal E | ahmadnofal5@hotmail.com | Did not reply |
| Rongsaard 2014 | Rongsaard N | nopnarueporn@gmail.com | Responded |
| Sage 2011 | Kouba DJ | dkouba1@hfhs.org | Did not reply |
| Tanzi 2004 | Alster TS | talster@skinlaser.com | Did not reply |
| Zhang 2013 | Chen J | xdchen@medmail.com.cn | Did not reply |