Assessing the relationship between health utilities, quality of life, and health services use in Alzheimer's disease.

OBJECTIVES

To examine the relationship between use of multiple health services and health utilities, quality of life and other factors in Alzheimer's disease (AD).

DESIGN

Data were obtained via caregiver proxy at baseline and 3- 6- and 9-months post-random assignment among 421 community-dwelling AD patients participating in the CATIE-AD trial of anti-psychotic medications. Service use includes both institutional and outpatient services. Correlates include the AD-Related Quality of Life Scale (ADRQoL), Health Utilities Index (HUI)-III, Neuropsychiatric Inventory, Mini Mental Status Examination, and AD-Cooperative Study Activities of Daily Living Scale. Chi squared tests, t-tests and logistic regression (using general estimating equations) were used to examine the correlates of service use.

RESULTS

Three quarters (74.2%) used at least one service each month. Average monthly utilization rates for specific service types were: 4.5%, inpatient hospital; 5.6%, nursing home; 3.9%, residential care; 44.0%, AD-related outpatient; 9.4%, mental health outpatient; and 45.5%, medical-surgical outpatient. The likelihood of using any service was higher among older patients [Odds Ratio (OR) = 1.03] and non-Hispanic Whites (OR = 1.61). Each 0.10 increment on the Health Utilities Index (HUI)-III was associated with a 7.0% decrease in the odds of using one or more service (OR = 0.93). The odds of using outpatient and institutional services were 6.0% and 10.0% lower, respectively, for each 0.10 increment on the HUI-III (OR = 0.94, OR = 0.90). The AD-Related Quality of Life Scale proved significantly related to outpatient medical-surgical services only (OR = 1.01).

CONCLUSION

Findings suggest that the HUI-III could be combined with other known correlates of service use to inform population planning associated with AD.