Feasibility of ADL Test Construction Based on IRT

抄録

The purpose of this study was to examine the feasibility of constructing a new test by analyzing the item characteristic of motor function and physical independence ADL tests based on the item response theory (IRT). Subjects were 137 males and 198 females, aged over 65 years old. The average of age was 69.2±5.4 years old (male 70.4±5.5, female 68.7±5.2). The physical independence and the motor function ADL test were consisted of 15 items with 2 options. Unidimesionality of physical independence and motor function ADL tests were satisfied for item characteristic analysis. Item difficulty and item discrimination were calculated by using two-parameter logistic model. Item characteristic curves, item information functions, test characteristic curves, and test information functions were obtained from the item difficulty and the item discrimination. In the new test, 70% of the whole subjects were able to achieve 80% or more based on the item characteristic. The item difficulty, the item discrimination, and the amount of item information of each item were confirmed. Eighty % of the whole subjects were able to achieve 80% or more in physical independence ADL test. Fifty % of the whole subjects were able to achieve 80% or more in motor function ADL test. It was concluded that the new test satisfied target test characteristics could be composed from previous test items applying IRT techniques.