The utility of the Ascertain Dementia Eight-item Questionnaire (AD8) and Mini-Cog in detecting cognitive impairment in older surgical patients – The Detect CI study

Background: Brain health is often overlooked before surgery, missing an opportunity to identify at-risk patients. This study aimed to (1) examine the diagnostic performance of two ultra-rapid cognitive screening tools, the Ascertain Dementia Eight-item Questionnaire (AD8) and Mini-Cog, against a tool validated in surgical populations, the Montreal Cognitive Assessment (MoCA); and (2) compare preoperative patient-centered assessments and postoperative outcomes between those with and without cognitive impairment (CI). Methods: CI was classified by scoring ≥2 on the AD8, ≤2 on the Mini-Cog, and/or ≤25 on the MoCA in non-cardiac patients ≥65 years old. Results: Of 394 participants, 35 % had preoperative CI on the MoCA, 15 % on the AD8, and 12 % on the Mini-Cog. Both the AD8 and Mini-Cog demonstrated moderate area under the curve, with superior specificity over sensitivity. In contrast to the Mini-Cog, participants with CI on the MoCA and AD8 reported poorer preoperative patient-centered assessments than those without. Specifically, the AD8 was associated with poorer functional disability, frailty, anxiety and/or depression, pain level, sleep quality, and quality of life. Contrary to the MoCA and Mini-Cog, CI on the AD8 was associated with higher all-cause complications (15.1 % vs. 3.7 %, P = 0.003), emergency department visits (11.3 % vs. 2.5 %, P = 0.007), and composite adverse outcomes (15.1 % vs. 4.6 %, P = 0.008) at 90 days. Conclusions: Although the AD8 and Mini-Cog demonstrated comparable diagnostic accuracy for CI, the AD8 provided additional insights into preoperative patient-centered assessments and 90-day adverse outcomes. Our study emphasizes the importance of preoperative screening for CI, highlighting the AD8 as a valuable tool.