TY - JOUR
T1 - The relationship of medical, demographic and psychosocial factors to direct and indirect health utility instruments in rheumatoid arthritis
AU - Witney, AG
AU - Treharne, Gareth
AU - Tavakoli, M
AU - Lyons, Antonia
AU - Vincent, K
AU - Scott, DL
AU - Kitas, George
PY - 2006/2/20
Y1 - 2006/2/20
N2 - OBJECTIVES: Cost-effectiveness analysis (CEA) is essential for the comparison of treatments for rheumatoid arthritis (RA). CEA centres on accurate measurement of health utility (HU) preferences. Direct measures of HU in RA patients demonstrate weaker correlations with health status (functional disability and pain) than indirect measures. We examined whether demographic and psychosocial factors relate to HU in RA patients. METHODS: HU was measured for 142 RA patients (76% women; mean age 58.75 yr) directly through standard gamble (SG) and time trade-off (TTO), and indirectly on the EuroQol (EQ-5D). Current pain (100 mm visual analogue scale) and recent functional disability (Health Assessment Questionnaire; HAQ) were assessed. A subsample of 48 provided demographic and psychosocial information (education, employment, marital/family status, knowledge about RA, medication beliefs, desirable responding, social support, optimism, and the Hospital Anxiety and Depression Scale; HADS). RESULTS: Direct HU had higher means (SG = 0.88, TTO = 0.86) than indirect HU (EQ-5D = 0.52). HAQ functional disability correlated with SG (r = - 0.28), TTO (r = - 0.31) and EQ-5D (r = - 0.67). Current pain correlated with TTO (r = - 0.19) and EQ-5D (r = - 0.36). HADS depression correlated with TTO (r = - 0.35) and EQ-5D (r = - 0.64); HADS anxiety also correlated with EQ-5D (r = - 0.46). CONCLUSIONS: Demographic and psychosocial factors cannot completely explain either the significant differences between direct and indirect HUs in RA patients or the moderate correlations of direct HUs with health status. Characteristics of the SG and TTO may make them inappropriate for HU assessment and CEA among RA patients.
AB - OBJECTIVES: Cost-effectiveness analysis (CEA) is essential for the comparison of treatments for rheumatoid arthritis (RA). CEA centres on accurate measurement of health utility (HU) preferences. Direct measures of HU in RA patients demonstrate weaker correlations with health status (functional disability and pain) than indirect measures. We examined whether demographic and psychosocial factors relate to HU in RA patients. METHODS: HU was measured for 142 RA patients (76% women; mean age 58.75 yr) directly through standard gamble (SG) and time trade-off (TTO), and indirectly on the EuroQol (EQ-5D). Current pain (100 mm visual analogue scale) and recent functional disability (Health Assessment Questionnaire; HAQ) were assessed. A subsample of 48 provided demographic and psychosocial information (education, employment, marital/family status, knowledge about RA, medication beliefs, desirable responding, social support, optimism, and the Hospital Anxiety and Depression Scale; HADS). RESULTS: Direct HU had higher means (SG = 0.88, TTO = 0.86) than indirect HU (EQ-5D = 0.52). HAQ functional disability correlated with SG (r = - 0.28), TTO (r = - 0.31) and EQ-5D (r = - 0.67). Current pain correlated with TTO (r = - 0.19) and EQ-5D (r = - 0.36). HADS depression correlated with TTO (r = - 0.35) and EQ-5D (r = - 0.64); HADS anxiety also correlated with EQ-5D (r = - 0.46). CONCLUSIONS: Demographic and psychosocial factors cannot completely explain either the significant differences between direct and indirect HUs in RA patients or the moderate correlations of direct HUs with health status. Characteristics of the SG and TTO may make them inappropriate for HU assessment and CEA among RA patients.
KW - health utility
KW - rheumatoid arthritis
KW - time trade-off
KW - standard gamble
KW - disability evaluation
UR - http://www.scopus.com/inward/record.url?scp=33747869954&partnerID=8YFLogxK
U2 - 10.1093/rheumatology/kel027
DO - 10.1093/rheumatology/kel027
M3 - Article
C2 - 16461437
SN - 1460-2172
SN - 1462-0332
VL - 45
SP - 975
EP - 981
JO - Rheumatology
JF - Rheumatology
IS - 8
ER -