Objective: To assess the importance of co-morbidities as a determinant of care costs and health-related quality of life in patients with Alzheimer’s disease.
Design: In a prospective observational study data was collected by questionnaires to patients, their primary caregiver and a responsible physician.
Materials and Methods: 272 patients with Alzheimer’s disease (AD) and their primary caregiver (spouse or child to the patient in most cases) were enrolled from memory clinics at six centers in Stockholm, Uppsala and Piteĺ (Sweden), Copenhagen (Denmark), Kuopio (Finland) and Bergen (Norway). Data collection was undertaken in three phases: at baseline, after 6 months and after 12 months. Formal and informal care costs were estimated by combining resource usage data with unit costs for Sweden. Health utilities were estimated from EuroQoL EQ-5D scores provided by patients and also by caregivers as proxies, using population weights from the literature. Also the quality of life instrument QoL-AD was administered to patients and caregivers. A brief version of the neuropsychiatric inventory (NPI) was included, as well as information about the occurrence of specific diagnoses including cardiovascular disease, diabetes, autoimmune disease, cancer, pulmonary disorders and neurological disease. Panel data regression methods were used to estimate the influence on costs and health utilities from the level of cognitive function, assessed with the mini-mental state examination (MMSE), NPI, co-morbidities and background factors such as age, gender and education. To account for the skewed distribution of cost data a two-part model was applied.
Results: The most common diagnoses reported were hypertension (34% of patients at baseline), angina pectoris (13%), heart failure (11%), diabetes (7%), thyroid disease (7%). 58% of patients had at least one diagnosis other than AD. The probability of requiring formal care was related to the number of co-morbidities, as well as the NPI score and the age of the patient. Among patients requiring formal care, costs were higher for those with lower MMSE scores. Informal care costs were strongly related to the MMSE score and the NPI but not to the number of co-morbidities. Proxy-rated health utilities ranged from 0.69 (MMSE>25) to 0.33 (MMSE<10) and were also related to the NPI score. Heart failure was the only diagnosis with a significant negative impact on proxy-rated health utilities.
Conclusion: In Alzheimer’s disease, the most important determinants of costs of care and health-related quality of life are level of cognitive impairment and the occurrence of neuropsychiatric manifestations. Patients with one or several co-morbidities have higher utilization of health care resources and higher formal care costs.
Back to S073 Health Economics and Public Health Implications of Alzheimer's Disease with and without Medical Co-Morbidities
Back to The Eleventh International Congress