“…Objective versus subjective sleep measures. There was consensus across articles using objective sleep measures such as PSG, sensors, and actigraphy, that total sleep time (TST) did not significantly vary between healthy older adults and those with MCI or AD, which ranged between 6.5 and 8.5 hours among participants from various studies (Cavuoto et al, 2019;Hayes et al, 2014;Hita-Yanez et al, 2012;Sanchez-Espinosa et al, 2014;Tadokoro et al, 2020). However, the findings of one study (Yu et al, 2017) in which researchers measured sleep using the Pittsburgh Sleep Quality Index (PSQI) contradicted this consensus.…”