The AIMS2‐SF. A short form of the arthritis impact measurement scales 2

Abstract Objective . To develop a short form of the Arthritis Impact Measurement Scales 2 (AIMS2) questionnaire, preserving content validity as the priority criterion. Methods . A 2‐step reduction procedure was used: 1) Delphi technique, with 1 panel of patients and 1 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 selection 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 completed the AIMS2 twice prior to the initiation of methotrexate (MTX) treatment and 3 months post‐initiation of MTX treatment. Results . The 2 panels reached consensus on a 26‐item AIMS2‐SF (54.4% reduction from the AIMS2). Factor analysis showed preservation of the 5‐component structure. Convergent validity (Physical and Symptom components with clinical 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 component [0.08]) were very close to the values for the original AIMS2. Conclusion . The AIMS2‐SF is a shorter version of the AIMS2 (i.e., available in 2‐page format) and has psychometric properties similar to those of the AIMS2.