Ability to perform activities of daily living is the main factor affecting quality of life in patients with dementia

BACKGROUND: Dementia is a chronic illness associated with a progressive loss of cognitive and intellectual abilities, such as memory, judgment and abstract thinking. The objective of this study was to assess the health utilities of patients with dementia in Europe and identify the key factors influencing their Health-Related Quality of Life (HRQol). METHODS: This study used cross-sectional data from the Odense study; a Danish cohort of patients aged 65–84 living in Odense, Denmark. A total of 244 patients with mild to severe dementia were interviewed together with a caregiver about their health status and activities of daily living (ADL). Alzheimer's disease was diagnosed according to the NINCDS-ADRDA criteria for probable dementia. Vascular dementia and other types of dementia were diagnosed according to the DSM-IIIR criteria. Severity of dementia was defined by score intervals on the Mini Mental State Examination score: mild (MMSE 20–30), moderate (MMSE 10–19), and severe (MMSE 0–9). Based on the ADL information, the patients' dependency level was defined as either dependent or independent. Questions from the Odense Study were mapped into each of the five dimensions of the EQ-5D in order to assess patients' HRQol. Danish EQ-5D social tariffs were used to value patients' HRQol. A regression analysis of EQ-5D values was conducted with backward selection on gender, age, severity, ADL level and setting in order to determine the main factor influencing HRQoL. RESULTS: The EQ-5D weight in patients independent upon others in ADL was 0.641 (95% CI: [0.612–0.669]), and in those dependent upon others was 0.343 (95% CI: [0.251–0.436]). CONCLUSION: Dependency upon others to perform ADL was the main factor affecting HRQoL.