Diagnostic accuracy of different diagnostic systems in estimating the incidence of delirium among surgery patients has not been investigated to date. Therefore, the authors evaluated the frequency of delirium according to DSM-IV and ICD-10 criteria and the cutoff values of the Memorial Delirium Assessment Scale (MDAS) and Delirium Index in 563 patients undergoing cardiac surgery. DSM-IV criteria were found as more inclusive, while ICD-10 criteria were more restrictive in establishing a diagnosis of postoperative delirium. The cutoff scores of 10 on the MDAS and 7 on the Delirium Index were optimal to the presence or absence of delirium.
Trial registration: ClinicalTrials.gov NCT00784576.