Supplementary Material for: DAD-6: A 6-ltem Version of the Disability Assessment for Dementia Scale Which May Differentiate Alzheimer’s Disease and Mild Cognitive Impairment from Controls

Background: The need to detect early changes in instrumental activities of daily life led us to modify the Disability Assessment for Dementia Scale (DAD) by focusing on executive components of 6 instrumental items (DAD-6). Aim: To evaluate the relevance of the DAD-6 for detecting early impairment in a nondemented population. Methods: The DAD-6 was administered to informants of 84 patients: 31 with mild dementia (MD), 53 with mild cognitive impairment (MCI) and 55 healthy controls. Results: DAD-6 scores gradually decreased with increasing severity of the cognitive status [18 in healthy controls vs. 15.1 ± 3.2 in MCI versus 9.6 ± 3.5 in MD, p < 0.0001). Receiver-operating characteristic curve analyses yielded an optimal cut score of 14 to distinguish MCI from MD with a sensitivity of 0.83 (95% confidence interval 0.74–0.92) and a specificity of 0.84 (0.71–0.94), and a cut score of 15 to distinguish single-domain MCI from multi-domain MCI with a sensitivity of 0.96 (0.90–0.99) and a specificity of 0.54 (0.33–0.75). Conclusion: The DAD-6 reliably detects early loss of autonomy due to cognitive impairment.