The International Dementia Alliance Instrument for Feasible and Valid Staging of Individuals with Dementia by Informal Caregivers.

Abstract

To assess the feasibility and validity of the International Dementia Alliance (IDEAL) instrument for Informal Caregivers (IDEAL-IC), which is based on the IDEAL instrument for professionals (IDEAL-P), for staging individuals with dementia. Cross-sectional. Memory clinic of a university hospital. Informal caregivers of 73 community-dwelling elderly adults referred to a memory clinic and six geriatric registrars. Caregivers completed the IDEAL-IC; physicians completed the original IDEAL-P and the Clinical Dementia Rating sum of boxes (CDR-SB). Missing items and floor and ceiling effects were reviewed to assess feasibility. To test construct validity, a priori hypotheses were defined for expected correlations between IDEAL-IC, IDEAL-P, and CDR-SB scores. Seventy-three IDEAL-IC instruments were completed, 86% of which had no missing items. Three percent of all 730 individual items were missing. No floor or ceiling effects were detected. CDR scores were 0 7%, 0.5 in 33%, 1 in 27%, 2 in 10%, and unknown in 23%. IDEAL-IC scores correlated highly with IDEAL-P scores (correlation coefficient (r) = 0.70) and with CDR-SB scores (r = 0.65) as expected; the difference between these two correlations was smaller than expected. Agreement between IDEAL-IC and IDEAL-P scores was 34% within a range of 1 point difference on 36-point scales, 57% within a range of two points, and 81% within a range of five points. Correlation between IDEAL-P and CDR-SB was very high (r = 0.85). Results of this study indicate good feasibility and high validity of staging dementia by informal caregivers using the IDEAL-IC.