Registration of attentional function as a predictor of incident delirium (the RAPID study)

Introduction: Older adults undergoing elective surgery have a high risk of developing postoperative delirium (POD). Validated models predicting POD are scarce. This study investigated whether preoperative impairment of attentional function predicts POD in older adults without previously diagnosed cognitive impairment. Methods: In this prospective cohort study we recruited patients aged ≥70 years preceding major elective surgery. Preoperatively a visual vigilance test was administered to determine intra-individual reaction-time variability. Postoperatively, presence of delirium was screened daily. Results: We recruited 152 patients, 25 (16.4%) developed POD. Intra-individual reaction-time variability was not significantly different between patients with or without POD (0.18 ± 0.08 ms vs 0.22 ± 0.11 ms; P = 0.087). Receiver operating characteristic analyses indicated a poor accuracy for POD (area under the curve 0.609 ± 0.63). Except for surgery duration, no clinically significant between-group differences were found for secondary outcome parameters. Discussion: Preoperative intra-individual reaction time variability does not predict the incidence of POD in older patients undergoing major elective surgery.