Correction: “Is this sedation?” – a Group Delphi process to define cut-off doses and dosing intervals for potentially sedating drugs in palliative care - Sabine H. Krauss; Constanze Rémi; Claudia Bausewein; Jeremias Bazata; Alina Grebe; Christoph Ostgathe; Jan Schildmann; Eva Schildmann; on behalf of the iSedPall study group (BMC Palliative Care)