Development and validation of a preference weight multiattribute health outcome measure for rheumatoid arthritis.
OBJECTIVE
To develop and validate multiattribute measures for patients with rheumatoid arthritis (RA) to report health states and estimate preference weights.


METHODS
Survey materials were mailed to 748 patients. Factor analysis, an item response theory-based model, and an internal consistency test were used to identify attributes and evaluate items. Two multiattribute preference weight functions (MAPWF) were constructed. Construct validity of the new measures was then tested.


RESULTS
Four hundred eighty-seven patients returned the survey; 24 items on 6 health attributes were selected to form the new outcomes measure. Two MAPWF were derived with preference weights measured with time tradeoff and visual analog scales as dependent variables. All validity test results were statistically significant.


CONCLUSIONS
Our results reveal that the new measures are reliable and valid in assessing health states and associated preference weights of patients with RA.
Chiou
Chiun-Fang
CF
Amgen, Inc., Thousand Oaks, California, USA.
Suarez-Almazor
Maria E
ME
Sherbourne
Cathy D
CD
Chang
Chih-Hung
CH
Reyes
Carolina
C
Dylan
Michelle
M
Ofman
Joshua
J
Wallace
Daniel J
DJ
Mizutani
Wesley
W
Weisman
Michael
M
D000203:Activities of Daily Living; D001172:Arthritis, Rheumatoid / Q000503:physiopathology / Q000523:psychology* / Q000628:therapy; D005260:Female; D006304:Health Status; D006801:Humans; D008297:Male; D017060:Patient Satisfaction; D011594:Psychometrics / Q000295:instrumentation*; D012219:Rheumatology / Q000379:methods*; D012720:Severity of Illness Index; D011795:Surveys and Questionnaires; D016896:Treatment Outcome