Study	Date trial author contacted (first)	Data requested from trial author (short summary)	Date trial author provided data (first)	Data trial author provided (short summary)
Choi 1999	6 Jan 2020	‐ Random sequence generation ‐ Allocation concealment	7 Jan 2020	Clinical trial agent managed this study. Central randomizations and allocation concealments may have been performed but the methods were not clearly confirmed in detail.
de Andrade 2007	6 Jan 2020	‐ Random sequence generation ‐ Allocation concealment	6 Jan 2020	The contact information is out of date and not possible to follow up.
Ham 2009	6 Jan 2020	‐ Random sequence generation ‐ Allocation concealment	6 Jan 2020	Available data were not provided.
Kim 1999	6 Jan 2020	‐ Random sequence generation ‐ Allocation concealment	7 Jan 2020	Clinical trial agent managed this study. Randomizations and allocation concealments maybe have been performed but the methods were not clearly confirmed in detail.