Objectives: Quality of life (QoL) is a major outcome parameter in dementia care. Self-ratings are considered the best way to evaluate QoL, but staff-ratings also provide valid results. In particular, the discrepancies between self-ratings and staff-ratings are underrepresented. The aim was to identify characteristics of people with dementia that improve the probability of completing a self rating QoL instrument on the 'Quality of Life - Alzheimers' Disease' (QoL-AD). Additionally, a level of agreement was set between self-rated and staff-rated QoL-AD and possible influencing factors.
Method: A cross-sectional study was conducted in 2010 in Berlin. Using the instrument QoL-AD, the self- and staff-rated QoL of people with dementia was assessed.
Results: 104 residents (73.1% female, mean age: 79.0 years, mean cognitive function (MMSE): 11.5) were included in this research project. 49 (47.1%) residents were able to complete the QoL-AD questionnaire. A predictor to complete the QoL-AD was the MMSE-part 'language'. Residents rated their QoL as significantly higher than the nursing staff did. If the primary nurse rated the QoL, a significantly better agreement was identified.
Conclusion: The study generated new findings concerning a better understanding of QoL measurements. The results suggest the usefulness of performing self-ratings whenever possible. If proxy-ratings have to be used, these should be performed by primary nurses only in order to get reliable results.