THE AIMS2-SF - A SHORT-FORM OF THE ARTHRITIS IMPACT MEASUREMENT SCALES-2

Objective. To develop a short form of the Arthritis Impact Measurement Scales 2 (AIMS2) questionnaire, preserving content validity as the pr iority criterion. Methods. A 2-step reduction procedure was used: 1) D elphi technique, with I panel of patients and I panel of experts each selecting 1 set of items independently; and 2) nominal group technique , where members of both panels reached consensus on the final selectio n of items, using information derived from item analysis. Psychometric properties of the AIMS2-Short Form (AIMS2-SF) and AIMS2 were compared using data from a cohort of 127 rheumatoid arthritis patients who com pleted the AIMS2 twice prior to the initiation of methotrexate (MTX) t reatment and 3 months postinitiation of MTX treatment. Results. The 2 panels reached consensus on a 26-item AIMS2-SF (54.4% reduction from t he AIMS2). Factor analysis showed preservation of the 5-component stru cture. Convergent validity (Physical and Symptom components with clini cal variables: r = 0.24-0.59), test-retest reproducibility (intraclass correlation coefficient >0.7), and sensitivity to change at 3 months (standardized response mean 0.36-0.8, except Social Interaction compon ent [0.08]) were very close to the values for the original AIMS2. Conc lusion. The AIMS2-SF is a shorter version of the AIMS2 (i.e., availabl e in 2-page format) and has psychometric properties similar to those o f the AIMS2.