Validation of the Malay 3-Minute Diagnostic Interview for Confusion Assessment Method in a surgical population

Abstract

Background: Delirium is a common postoperative complication among elderly which can be easily missed and leads to poorer outcomes. The 3-Minute Diagnostic Assessment for Confusion Assessment Method (3D-CAM) is a short and structured tool to assess delirium by healthcare staff with minimal training. This study aimed to validate the translated Malay 3D-CAM (M3D-CAM) in postoperative surgical patients. Methods: In this prospective diagnostic study, 3D-CAM was translated into Malay and two assessors (1 and 2) independently interviewed surgical patients above 65 years old with M3D-CAM on postoperative day one. A psychiatrist diagnosed postoperative delirium according to the Diagnostic and Statistical Manual of Mental Disorders 5th Edition (DSM-5) as the reference standard. The sequence of examinations was done randomly with all results blinded to each other and the diagnostic characteristics of M3D-CAM analysed with k coefficient used to evaluate reliability. Results: A total of 427 patients were screened, 111 recruited with a final 100 paired interviews completed. Their mean age was 72 (± 6) years old. Two-thirds of patients were proficient in Malay and English, therefore assessed in both 3D-CAM and M3D-CAM. Delirium was identified in 11% and 12% of patients by assessors 1 and 2 respectively while compared to DSM-5, M3D-CAM had 80% and 90% sensitivity with 96.7% and 97.7% specificity. M3D-CAM had excellent inter-rater reliability (85%), substantial parallel reliability (70%) and features 1 and 3 with substantial parallel agreement (p <0.001). Conclusion: This study demonstrated that M3D-CAM is reliable and valid for delirium assessment in the postoperative setting.