Hendriks AAj et al. – This study investigated the use of DEMQOL and DEMQOL–proxy in patient–reported outcomes measures of health–related quality of life with dementia. The score of DEMQOL and DEMQOL–proxy improved using the Rasch measurement model. However, future work should focus on problems identified with content and response option.

Methods

• Modern psychometric methods were used to re–evaluate DEMQOL and DEMQOL–proxy. In addition, scale to sample targeting, ordering of item thresholds, item fit to the model, differential item functioning, local independence, unidimensionality, and reliability on the full set of items and a smaller item set were evaluated.

Results

• The smaller item set performed better than the original item set for both DEMQOL and DEMQOL–proxy. A revised scores were developed using the items from the smaller set.