Evaluation of Activities of Daily Living/Instrumental Activities of Daily Living to Accurately Determine Severity of Moderate and Severe Alzheimer's Disease: Comparison of Assessments by Receiver Operating Characteristic Curve and Discriminant Analyses.

Aim: The aim of this study was to determine Activities of Daily Living/Instrumental Activities of Daily Living (ADL/IADL) evaluations that will enable better understanding of the severity of Alzheimer's disease (AD).

Methods: AD patients were evaluated by Functional Independence Measure (FIM), Hyogo Activities of Daily Living Scale (HADLS), and Assessment of Motor and Process Skills (AMPS) to identify the assessments that will enable highly precise discrimination of AD Clinical Dementia Rating (CDR) 2 (moderate) and CDR3 (severe) using receiver operating characteristic (ROC) curve and discriminant analyses.

Results: The participants were 75 AD patients (CDR2 = 50, mean age = 80.3 ± 5.9 years; CDR3 = 25, mean age = 78.3 ± 9.0 years). The evaluation methods consisted of FIM, HADLS, and AMPS. The results were divided into FIM-M, FIM-C, HADLS-ADL, HADLS-IADL, AMPS-motor skills, and AMPS-process skills. The values for the area under the curve (AUC) were compared by ROC curve and discriminant analyses. AUC values for FIM-C and AMPS-process skills were 0.956 and 0.947, respectively. With these two evaluations only, values ≥0.9 were shown. Moreover, the AUC of the discrimination score (combination of the FIM-C and AMPS-process skills) was significantly higher than those for FIM-M, FIM-C, HADLS-ADL, HADLS-IADL, and AMPS-motor skills.

Conclusions: The results demonstrated that evaluation by FIM-C and AMPS-process skills methods was useful for discriminating between CDR2 (moderate) and CDR3 (severe) AD. Moreover, the results indicated that these two evaluation methods enabled more accurate determination of severity and the spared capabilities of AD patients.