[The validity and reliability of a Japanese version of Arthritis Impact Measurement Scales in patients with rheumatoid arthritis].

A Japanese version of Arthritis Impact Measurement Scales (Japanese-AIMS) was developed after the original AIMS Version 2 (AIMS 2). We then conducted a Quality of Life measurement of 691 patients with Rheumatoid Arthritis (RA) with this newly developed questionnaire. Based on the data collected, the validity and reliability of the Japanese-AIMS was examined. The validity of the Japanese-AIMS, which was assessed by the examination of internal consistency among items and through factor analysis, was almost comparable with that of the original AIMS 2. QOL scales were also validated using internal standards based on the subject's responses to other items in the questionnaire. The test-retest reliability, which was the correlation of scale scores between two tests administered 4-5 weeks apart, was slightly lower than the original one. We conclude that the validity and reliability of the Japanese AIMS were comparable with those of the original one, though there could be possibly improved by the minor revision of phrasing. The large scale QOL measurement study with RA patients is under way, using the Japanese-AIMS with minor revision.