Early postoperative neurocognitive complications in elderly patients: comparing those with and without preexisting mild cognitive impairment- a prospective study.

"Declarations Ethics approval and consent to participateAll patients in the study willingly agreed to participate and received information about the study both verbally and in written form. The patients completed the written informed consent form before their participation. This study was conducted with the prior approval of the Institutional Review Board, Faculty of Medicine Siriraj Hospital, Mahidol University (Si 515/2017). Consent for publicationNot applicable. Competing interestsThe authors declare no competing interests. Competing interests The authors declare no competing interests."

"Funding This study was supported by the Faculty of Medicine, Siriraj Hospital Mahidol University, Bangkok, Thailand (grant number [IO] R016037003). Open access funding provided by Mahidol University"

"Trial registration This trial was retrospectively registered in the Thai Clinical Trials Registry on 15/01/2019 (registration number: TCTR20190115001)."