DIMENSIONS Winter 1999

SPOTLIGHT ON RESEARCH: ADRC RESEARCHERS PRESENT QUALITY OF LIFE MODEL

by Cheryl Dawes

UW ADRC researchers collaborating on an investigation of ways to evaluate the quality of life (QOL) in people with Alzheimer's disease presented their research at the annual meeting of the Gerontological Society of America in Novemberber. The meeting is the oldest and largest gathering devoted to based gerontological research. Drs. Rebecca Logsdon, Linda Teri, and Sue McCurry from the UW Department of Psychosocial and Community Health, and Dr. Laura Gibbons from the UW Department of Environmental Health, held a symposium entitled "Modeling quality of life in community-residing individuals with Alzheimer's disease." The symposium, which consisted of presentations by each of the ADRC researchers, was attended by over 100 researchers and clinicians. Together, the talks comprised an overview of the model of QOL the researchers are testing in a population based sample of 140 individuals with Alzheimer's disease.

In recent years, QOL has begun to receive a great deal of attention among AD researchers due to the increasing need to provide evidence that newly developed treatments are noticeably improving the lives of people with AD. However, there is little agreement about how to best evaluate QOL in these individuals. In the UW study, led by Logsdon and funded by the Alzheimer's Association and the National Institute of Aging, Logsdon and her colleagues have collected baseline information from pairs of participants with Alzheimer's and their caregivers. The researchers are using these data to test a theoretical model based on the idea that physical, interpersonal, environmental and psychological factors all contribute to an individual's overall quality of life.

During the symposium, each researcher presented data from a particular aspect ofthe study, including: study design and characteristics of the study sample; psychological status of participants and caregivers; sleep and behavioral characteristics of participants and caregivers; and subjective ratings of Iife quality by participants and caregivers.

By correlating objective measures of functional and cognitive status, psychological state and behavior problems with subjective ratings of satisfaction with life, the researchers are working to build an empirically based model of QOL in AD.

Study Description

Dr. Gibbons described the study design, explaining that each of the 140 community-dwelling participants was diagnosed with probable or possible AD based on a comprehensive evaluation and a consensus meeting. Baseline data have been collected and the participants will be re-evaluated every 6 months for 3 years. This will allow the researchers to record participant and caregiver assessments of quality of life and to evaluate the impact of participant health and physical status, cognitive and functional ability, mood, sleep, and behavioral disturbance, and caregiver mood, sleep, and burden on QOL over time. At baseline, the mean age of participants was 77. Most participants are married and living with spouses. Most are at least high school graduates. Gibbons reported a wide range of cognitive functional impairment among the study sample, but found that physical functioning inthe group is comparable to other adults of their age.

Psychological Status of Participants and Caregivers

Dr. Teri discussed components of psychological health of individuals with AD and their caregivers. She is evaluating the relationship of physical, functional and caregiver factors to depression in individuals with AD. Analyzing data *om the study sample, Teri found variation in the measurement of patient depression among the different scales used to assess patient and caregiver depression. She concluded that, although the measurement of patient depression needs further refinement and the ability to predict depression is limited, it is clear that patient and caregiver depression are associated.

Three factors were consistently associated with patient depression--caregiver depression, infrequent pleasant events and lack of mobility. More research is needed, but these results suggest an approach to reducing depressive symptoms in AD, Teri pointed out. "Identifying and encouraging pleasant activities, improving mobility, identifying and treating behavioral disturbances, and treating depressive symptoms in caregivers all may prevent or reduce depressive symptoms in individuals with AD.

Sleep and Behavioral Characteristics

Dr. McCurry addressed another factor under study-sleep and related characteristics of individuals with AD and their caregivers. Sleep problems are common among persons diagnosed with Alzheimer's disease (AD) and among AD caregivers. Worsening patient sleep has been linked to caregiver depression, burden and patient institutionalization, she noted. "However, there have been no studies on the interactions between participant and caregiver sleep, health, mood, and function."

To investigate how sleep factors may be related to QOL, McCurry collected baseline data from patients and caregivers about the quality, length and interruptions oftheir sleep at night and about their napping and feelings of sleepiness during the daytime. Patients tended to minimize their sleep problems; nearly all of them considered their sleep to be very good or satisfactory, she noted. Yet one-third of the patients were reported by caregivers to have trouble sleeping at night. Less than half ofthe caregivers considered their own sleep to be satisfactory. McCurry found a relationship between patient sleep disturbance and patient depression, memory loss, functional impairment, gender and ethnicity. She found the greatest influence on caregivers' sleep is depression.

Subjective Ratings of the Quality of Life

Dr. Logsdon concluded the seminar with a discussion of what constitutes QOL in AD and an evaluation of four hypothesized components of QOL (psychological, behavioral, functional and cognitive factors). Logsdon described the relative contributions of each of the components to the overall ratings of life quality collected from participants and their caregivers. Based on statistical analysis of the relationship between objective measures of the hypothesized components and subjective measures of QOL, Logsdon concluded that depression is strongly associated with QOL, but is not the only factor involved. Functional ability appears to be more important to QOL than cognitive status. In addition, their own levels of depression influence caregiver reports of QOL.

"Greater independence of functioning, higher levels of pleasant events and lower levels of depressive symptoms in both participants and their caregivers are associated with higher QOL in individuals with AD," she reported. "Future research with this sample will investigate predictors of changes in QOL over time and thus identify potential areas in which intervention will result in improved QOL over the course of the disease."

If you or anyone you know may be interested in participating in this study, or for more information, please call Amy Moore at 206-685-9169.

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