[Item function analysis on the Quality of Life-Alzheimer's Disease(QOL-AD)Chinese version, based on the Item Response Theory(IRT)].

OBJECTIVE: To introduce the Item Function Analysis(IFA) of Quality of Life- Alzheimer's disease(QOL-AD)Chinese version and to explore the feasibility of its application on Chinese patients with AD. METHODS: Two hundred AD patients were interviewed and assessed by QOL-AD, through the stratified cluster sampling method. Multilog 7.03. was used for Item Function Analysis. Difference scale(a), difficulty scale(b)and Item Characteristic Curve(ICC) of each item of QOL-AD were provided. RESULTS: Different scales of the item 1, 7 were below 0.6, while all the others were above 0.6. As for ICC. The first and last lines for the other items were monotonic in which the two in between were in inverted V-shape, with very steep slopes, except for the item 1 and 7. CONCLUSION: Results form the IFA showed that QOL-AD was applicable to be used in the Chinese patients with AD.