Funding for this research was provided by:
Japan Society for the Promotion of Science (16K11418)
Received: 28 November 2019
Accepted: 22 January 2020
First Online: 11 February 2020
Ethics approval and consent to participate
: This observational study, a part of an interventional trial to investigate the preventative effect of sleep promotion to delirium, was approved by the Institutional Review Board of Jichi Medical University Saitama Medical Center. Informed consent with written confirmation was obtained from patients (or their family when the patient was unable to sign). Only anonymized data were entered into the study database and used for analysis.
: Not applicable.
: The authors declare that they have no competing interests.