Objectives: 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.
Design: Cross-sectional.
Setting: Memory clinic of a university hospital.
Participants: Informal caregivers of 73 community-dwelling elderly adults referred to a memory clinic and six geriatric registrars.
Measurements: 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.
Results: 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).
Conclusion: Results of this study indicate good feasibility and high validity of staging dementia by informal caregivers using the IDEAL-IC.
Keywords: dementia; feasibility; informal caregiver; staging; validity.
© 2016, Copyright the Authors Journal compilation © 2016, The American Geriatrics Society.