Reduced quality-of-life ratings in mild cognitive impairment: analyses of subject and informant responses

Abstract

Objectives: To determine whether quality-of-life (QOL) ratings are reduced in mild cognitive impairment (MCI) and analyze correlations between QOL ratings and cognitive, neuropsychiatric, and functional indices in MCI.

Design: Cross-sectional.

Setting: The Easton Center for Alzheimer's Disease Research at the University of California, Los Angeles.

Participants: A total of 205 individuals who met criteria for normal cognition (n = 97) or MCI (n = 108). The MCI group included amnestic (n = 72) and nonamnestic (n = 36) MCI.

Measurements: QOL was assessed using subject and informant ratings on the Quality of Life-Alzheimer's Disease (QOL-AD) scale. Cognitive performance was assessed with the National Alzheimer's Disease Coordinating Center Uniform Data Set neuropsychological battery. Neuropsychiatric symptoms were assessed with the Geriatric Depression Scale (GDS) and the Neuropsychiatric Inventory. Functional abilities were assessed with the Functional Activities Questionnaire (FAQ).

Results: The normal cognition group had significantly higher QOL-AD scores than the MCI group on both subject and informant assessments. Individual item analyses indicated that the largest group differences were seen on the mood and memory items. Similar QOL-AD scores were seen in the amnestic and nonamnestic MCI subgroups. Multiple regression analyses within the MCI group indicated that QOL-AD ratings were not correlated with neuropsychological performance. Subject QOL-AD ratings were inversely correlated with GDS scores and informant QOL-AD ratings were inversely correlated with GDS, Neuropsychiatric Inventory, and FAQ scores.

Conclusions: Significant declines in QOL are seen in MCI and are associated with neuropsychiatric symptoms and functional decline. Interventions targeting mood symptoms and/or instrumental activities of daily living may improve QOL in MCI.

Figure 1

A) Total QOL-AD scores and B) average QOL-AD item scores in the NC and MCI groups. Error bars represent standard error of the mean. The number of subjects used for each analysis is indicated at the base of each bar. **p<0.05 vs. NC; **p<0.001 vs. NC.

Figure 2

Individual QOL-AD item scores in the NC and MCI groups using A) subject and B) informant ratings. Error bars represent standard error of the mean. *p<0.004 vs. NC.