The validity and responsiveness of generic utility measures in rheumatoid arthritis: a review.
OBJECTIVE
Cost-utility analysis is increasingly important as healthcare providers aim to invest scarce resources in interventions offering the greatest health benefit. The ability to attach utility values to health states is essential, and is increasingly performed using generic scales. However, the evidence regarding the validity of generic utility scales in rheumatoid arthritis (RA) is unclear. We summarize and review evidence on the validity and comparative performance of generic utility scales in RA.


METHODS
We searched the English-language medical literature for studies using utilities in RA between 1980 and mid-2006. Reports describing primary evidence of the validity or performance of a generic utility scale in RA were selected, summarized, and reviewed using the OMERACT filter.


RESULTS
In total 923 articles were identified, of which 228 reported the use of utility scales in RA; 26 studies related to the validation or evidence of generic utility scales in RA, the EQ-5D, Health Utility Index-2 (HUI2) and HUI3, SF-6D, and Quality of Well-Being Scale. The EQ-5D, HUI2 and HUI3, and SF-6D all have consistent evidence of construct validity and responsiveness in RA, but each has limitations.


CONCLUSIONS
The EQ-5D and HUI3 have been the most extensively studied instruments and show validity and responsiveness for use in RA, but both instruments have limitations. The SF-6D is relatively new and appears to have potential for use in milder RA, but needs further evaluation. More longitudinal head-to-head evaluation of measures is needed across the spectrum of RA disease severity to further investigate their comparative properties, and to seek consensus on the best utility measure for use in economic evaluation.
Harrison
Mark J
MJ
Arthritis Research Campaign Epidemiology Unit, and Health Economics Research at Manchester, The University of Manchester, Manchester, UK.
Davies
Linda M
LM
Bansback
Nick J
NJ
Ingram
Mary
M
Anis
Aslam H
AH
Symmons
Deborah P M
DP
D001172:Arthritis, Rheumatoid / Q000523:psychology*; D003362:Cost-Benefit Analysis; D019992:Databases as Topic; D006801:Humans; D011594:Psychometrics / Q000295:instrumentation*; D011788:Quality of Life; D019057:Quality-Adjusted Life Years; D015203:Reproducibility of Results; D018434:Sickness Impact Profile