The RHINE study received approval from the Regional Committees for Medical and Health Research Ethics in compliance with national legislation.

Bergen
The RHINE study was specifically approved by the Regional Committee for Medical Research Ethics of Western Norway (REK West) under reference numbers #236168 and #300765.

Iceland
The RHINE study was approved by the Icelandic Scientific Ethics Committee under reference numbers #90/101 (RHINE I), #99/070/AF (RHINE II), #VSN 10-112 (RHINE III) and #VSN 21-077 (RHINE IV).