Meeting Brochure and registration form      SMDM Homepage

Saturday, 22 October 2005 - 1:30 PM

EQ5D CHANGES RHEUMATOID ARTHRITIS (RA) QUALITY OF LIFE IN UNITED STATES: STUDY OF 11,289 RA PATIENTS

Kaleb Michaud, MS, Stanford University, Stanford, CA and Frederick Wolfe, MD, Arthritis Research Center Foundation, Inc, Wichita, KS.

PURPOSE Patients with rheumatoid arthritis (RA) have reduced quality of life (QOL). Using the EQ5D health measure, we report the QOL using US (EQ5D-US) and European (EQ5D-E) preferences and study their differences in RA by disability-index.  

METHODS During 2.5 years (2002-2004) in a US observational outcomes study, 11,289 RA patients completed 35,422 EQ5D and Health Assessment Questionnaire (HAQ) measurements. The EQ5D was transformed using standard European and newly published US preferences1. All analyses were adjusted by sex, age and calendar date with clustering by patient.  

RESULTS The study group had the following mean values (SD): 22.1% male, 62.0 (12.4) years old, and 1.03 (0.72) HAQ. The average QOL (95% C.I.) values were 0.63 (0.62,0.64) EQ5D-E, and 0.73 (0.72,0.73) EQ5D-US. The Table shows QOL and their difference by HAQ category. The per-patient change in HAQ over six months corresponded to a larger mean change in EQ5D-E vs EQ5D-US: -0.044 vs -0.034 when HAQ increased (N=8399, mean HAQ change 0.30) and 0.060 vs 0.038 when HAQ decreased (N=8074, mean HAQ change -0.30).  

CONCLUSIONS Even though the ordinal HAQ is scored the same in the US and Europe and is considered to be the primary outcome of disease severity and therapeutic effectiveness in RA, the corresponding EQ5D valuations are significantly different and nonlinear. This impacts effectiveness studies and could affect coverage decisions of RA treatments, as a reduction in disability corresponds to a reduced improvement in QOL in the US compared to Europe even though the US QOL is more generous.

1Shaw JW, Johnson JA, Coons SJ. US valuation of the EQ-5D health states: development and testing of the D1 valuation model. Med Care. 2005 Mar;43(3):203-20  

Table. EQ5D QOL By HAQ Score
HAQ N EQ5D-US (SD) EQ5D-E (SD)
0 - <0.25  5801 0.90 (0.19) 0.87 (0.27)
0.25 - <0.5  3589 0.84 (0.16) 0.80 (0.23)
0.5 - <0.75  3498 0.81 (0.15) 0.75 (0.22)
0.75 - <1.00 3571 0.78 (0.15) 0.71 (0.23)
1.00 - <1.25 3908 0.75 (0.17) 0.66 (0.25)
1.25 - <1.50 3834 0.71 (0.19) 0.60 (0.28)
1.50 - <1.75 3683 0.65 (0.21) 0.52 (0.32)
1.75 - <2.00 3248 0.59 (0.23) 0.44 (0.36)
2.00 - <2.25 2287 0.54 (0.24) 0.36 (0.38)
2.25 - <2.50 1199 0.49 (0.26) 0.28 (0.41)
2.50 - <2.75 549 0.42 (0.24) 0.18 (0.37)
2.75 - 3.00 255 0.31 (0.32) 0.03 (0.46)


See more of Joint ISOQOL Plenary - Quality of life
See more of The 27th Annual Meeting of the Society for Medical Decision Making (October 21-24, 2005)