Is there a relationship between processed electroencephalogram (EEG) characteristics during anaesthesia and general level of health?

Preoperative administration of: the Montreal Cognitive Assessment (MOCA), the WHO disability assessment schedule (WHODAS), the Edmonton Frailty assessment - and a timed ‘get up & go test’ (TUG). Administered/overseen by a single study researcher (for consistency) in the hospital setting prior to surgery. The assessments take approximately 30 minutes in total and, excepting the WHODAS, carried out only once. The WHODAS to be repeated (in-house) at Day 1 post-op and, usually, via telephone at Day 30 post-op. Duration of each follow-up approximately 5-10 minutes. EEG monitoring will be carried out by the procedural anaesthetist in the normal way and data collection will commence 15 minutes after the induction of anaesthesia and continue for a total of 20 minutes. Study description: Participants recruited between October 2018 and January 2019. Subjects were surgical candidates 65 years or older. Exclusion criteria included cardiac, neurological, or hip procedures, or inability to complete the initial health assessment questionnaires. Consenting participants completed four assessments: The WHO Disability Assessment Schedule (WHODAS), the Edmonton Frail Scale, the Timed Get Up and Go (TUG) and the Montreal Cognitive Assessment (MoCA). During anaesthesia a Masimo Sedline pEEG monitor was used. Anesthesia management was not standardized. Raw EEG data from the four frontal channels used by Sedline were downloaded and analysed offline. The primary outcome measure was mean absolute alpha power over the 20 min period commencing 15min after induction of anaesthesia. WHODAS was repeated at post-op days 1 & one month.