Rheumatoid and Arthritis Outcome Score

RAOS is developed as an instrument to assess the patients’ opinion about their leg and associated problems.
RAOS is patient-administered, the format is user friendly, and takes about 10 minutes to fill out.
RAOS is self-explanatory and can be administered in the waiting room or used as a mailed survey.
RAOS has been used in patients 20-85 years old.
RAOS is intended to be used for patients with chronic inflammatory joint diseases, such as rheumatoid arthritis, spondyloarthropathies, psoriatic arthritis and polyarthritis etc. and problems from the lower extremity.
RAOS is meant to be used over short and long time; to assess changes from week to week induced by treatment (medication, operation, physical therapy) or over years.
RAOS content validity was ensured through literature search and an expert panel of patients, medical doctors and physical therapists.
RAOS content validity for older subjects with RA is ensured since WOMAC Osteoarthritis Index (1, 2) is included in the RAOS questionnaire.
RAOS consists of 5 subscales; Pain, other Symptoms, Function in daily living, Function in sport and recreation and leg specific Quality of life. The last week should be taken into consideration when answering the questions. Standardized answer options are given (5 Likert boxes) and each question gets a score from 0 to 4. A normalized score (100 indicating no symptoms and 0 indicating extreme symptoms) is calculated for each subscale.
RAOS has high test-retest repeatability (ICC >0.76, Cronbach’s alpha >0.78).
RAOS construct validity has been determined in comparison with SF-36 (3, 4), the HAQ (5, 6) and four subscales of the AIMS2 (7, 8) and expected correlations were found (9).
RAOS responsiveness in subjects undergoing 3-4 weeks of multidimensional team care has been studied. A significant change was found in all scores. As expected, small to medium (0.39-0.44) effect sizes were found.
RAOS validation work is ongoing. RAOS is currently being used in a clinical study involving patients with rheumatoid arthritis undergoing arthroplasty of the knee or the hip. A validation paper regarding the RAOS has been published (9).
RAOS is currently available in two versions, an English version and a Swedish version.


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2. Wolfe F, Kong SX. Rasch analysis of the Western Ontario MacMaster questionnaire (WOMAC) in 2205 patients with osteoarthritis, rheumatoid arthritis, and fibromyalgia. Ann Rheum Dis 1999;58(9):563-8.
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8. Archenholtz B, Bjelle A. Reliability, validity, and sensitivity of a Swedish version of the revised and expanded Arthritis Impact Measurement Scales (AIMS2). J Rheumatol 1997;24(7):1370-7.
9. Bremander ABI, Petersson IP, Roos EM. Validation of the Rheumatoid and Arthritis Outcome Score (RAOS) for the lower extremity. Health and Quality of Life Outcomes 2003, 1:55.