Additional file 1: of Public availability of results of observational studies evaluating an intervention registered at ClinicalTrials.gov

Appendix 1: Emails for principal investigators indexed in ClinicalTrials.gov. Appendix 2: Flowchart of email responses. Appendix 3: Publication status according to the date of registration (before the start of the study, between the start and the study completion, after the study completion). (DOCX 31 kb)