[The proposal of the activities of daily living (ADL) index for institutionalized older adults].

The purpose of this study was to propose the ADL index constructed with a unidimensional scale based on item difficulty for institutionalized older adults. Six hundreds and three subjects (159 males and 444 females) were divided into the following four groups based on assisting devices for movement: G1 did not use assisting devices for movement; G2 used a stick or a walker; G3 used a wheelchair; G4 could not move. As the results of examinations from the points of the approximation of proportions, non-answer rates and agreement rates of each item according to 74 ADL items representing 9 ADL domains, the 27 ADL items were selected as utility items. The reliability and unidimensionality of the ADL index consisting of 27 items were considered to be high. As the results of examining the difficulty of items and ADL ability characteristics of each group, the ADL concerning movement and other lower limb activity in G1 and G2, and concerning changes of posture and manual activity in G3 and G4 were considered to reflect the individual differences of ADL ability, respectively. The numbers of ADL items which should first be assessed in each group were as follows: 20 items in G1; 21 items in G2; 21 items in G3; 11 items in G4.