Validation of the Dementia Care Assessment Packet-Instrumental Activities of Daily Living

Objective We aimed to evaluate the psychometric properties of the IADL measure included in the Dementia Care Assessment Packet (DCAP-IADL) in dementia patients. Methods The study involved 112 dementia patients and 546 controls. The DCAP-IADL was scored in two ways: observed score (OS) and predicted score (PS). The reliability of the DCAP-IADL was evaluated by testing its internal consistency, inter-rater reliability and test-retest reliability. Discriminant validity was evaluated by comparing the mean OS and PS between dementia patients and controls by ANCOVA. Pearson or Spearman correlation analysis was performed with other instruments to assess concurrent validity. Receiver operating characteristics curve analysis was performed to examine diagnostic accuracy. Results Chronbach's α coefficients of the DCAP-IADL were above 0.7. The values in dementia patients were much higher (OS=0.917, PS=0.927), indicating excellent degrees of internal consistency. Inter-rater reliabilities and test-retest reliabilities were statistically significant (p