[Measuring quality of life in nursing home residents with severe dementia: psychometric properties of the QUALID scale].

The Quality of Life in Late Stage Dementia (QUALID) Scale is an instrument to measure quality of life in patients with severe dementia over the last week by means of an interview with a nurse or nurse aid. We interviewed nurse aids on 48 patients with severe dementia in two nursing homes in The Netherlands to determine the psychometric properties of the Dutch translation of the QUALID. Test- retest reliability was good with an Concordance Correlation Coefficient (CCC) of 0.82, (95% Confidence Interval, CI 0.70 - 0.90); interrater reliability was moderate, with an CCC of 0.49 (CI: 0.17-0.72). There was a significant, but low correlation between QUALID ratings and discomfort ratings as observed with the Discomfort Scale-Dementia of Alzheimer Type (DS-DAT), amounting 0.32 (CI: 0.04 - 0.56). The QUALID seems appropriate for measuring quality of life in patients with advanced dementia, when one and the same rater monitors a patient over time in a longitudinal study.