The comparative responsiveness of the EQ-5D and SF-6D to change in patients with inflammatory arthritis.
OBJECTIVE
Comparative evidence regarding the responsiveness of the EQ-5D and SF-6D in arthritis patients is conflicting and insufficient across the range of disease severity. We examined the comparative responsiveness of the EQ-5D and SF-6D in cohorts of patients with early inflammatory disease through to severe rheumatoid arthritis (RA).


METHODS
Responsiveness was tested using the effect size (ES) and standardised response mean (SRM). Correlation of change in EQ-5D and SF-6D with disease specific measures was tested using Pearson correlations and the Steiger's Z test. Treatment response and self-reported change were used as anchors of important change.


RESULTS
The EQ-5D was more responsive to deterioration (ES ratio (EQ-5D/SF-6D): 1.6-3.0) and the SF-6D more responsive to improvement (ES ratio (SF-6D/EQ-5D): 1.1-1.8) in health. The SF-6D did not respond well to deterioration in patients with established severe RA (ES and SRM 0.08). The EQ-5D provided larger absolute mean change estimates but with greater variance compared to the SF-6D.


CONCLUSIONS
The comparative responsiveness of the EQ-5D and SF-6D differs according to the direction of change. The level of mean change of the EQ-5D relative to the SF-6D has implications for cost-effectiveness analysis. Use of the SF-6D in patients with severe progressive disease may be inappropriate.
ARC Epidemiology Unit, Stopford Building, The University of Manchester, Oxford Road, Manchester, M13 9PT, UK. mark.harrison@manchester.ac.uk
M J
MJ
Harrison
L M
LM
Davies
N J
NJ
Bansback
M J
MJ
McCoy
S M M
SM
Verstappen
K
K
Watson
D P M
DP
Symmons
D000328:Adult; D000368:Aged; D001172:Arthritis, Rheumatoid / Q000503:physiopathology / Q000523:psychology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D017063:Outcome Assessment, Health Care; D011788:Quality of Life; D015203:Reproducibility of Results; D011795:Surveys and Questionnaires