Ethgen Olivier, Tancredi Annalisa, Lejeune Eric, Kvasz Angela, Zegels Brigitte, Reginster Jean-Yves
WHO Collaborating Center for Public Health Aspects of Osteoarticular Disorders, University of Liège-CHU Sart Tilman, Avenue de l'Hôpital, Bâtiment B23, 4020 Liège, Belgium.
J Rheumatol. 2003 Nov;30(11):2452-9.
To establish whether health utility (time trade-off, TTO) and willingness to pay (WTP) values reflect clinical health outcome as evaluated by the Western Ontario McMaster Universities Osteoarthritis Index (WOMAC) in hip and knee osteoarthritis (OA).
One hundred twenty-eight patients with OA attending a specialized arthritis clinic were interviewed about their socioeconomic characteristics and administered the TTO technique and the WOMAC. Their WTP for 2 hypothetical anti-osteoarthritic drugs was also investigated: the first drug was said to provide a significant improvement in WOMAC dimensions and the second a complete cure of the disease. WTP was elicited by both discrete-choice and bidding game methods. Results. Answer rates were 89.1% for TTO, 98.4% for discrete-choice WTP for both scenarios, and 89.8% and 85.2% for bidding game WTP in the relief and the cure scenario, respectively. The mean TTO utility value was 0.84 (standard deviation 0.20). In discrete-choice, those accepting the bid had higher monthly income (EURO 1536.5 vs EURO 1060.1, p < 0.001, for the relief scenario and EURO 1449.3 vs EURO 1071.6, p < 0.001, for the cure scenario). With the bidding game format, WTP was positively correlated with income in both scenarios (r = 0.56, r = 0.55, p < 0.001). WTP measures differed equally between education and socioeconomic groups with those in favored groups consistently reporting higher WTP (Kruskal-Wallis tests statistics ranging from p < 0.01 to p < 0.001). Except for stiffness, WOMAC dimensions were correlated in the expected direction with TTO values (r = -0.27, p < 0.01 for pain and r = -0.36, r = -0.34, p < 0.001 for physical function and total score, respectively).
Whereas they showed good feasibility, WTP measures poorly reflected clinical condition and were mainly related to economic status and ability to pay. TTO was correlated with the WOMAC dimensions and may be considered closer to clinical situations than WTP. However, concern arises regarding the homogeneity of the study sample in terms of clinical severity, which may have precluded the identification of a relationship between WTP and clinical status.
确定健康效用（时间权衡法，TTO）和支付意愿（WTP）值是否反映了通过西安大略和麦克马斯特大学骨关节炎指数（WOMAC）评估的髋部和膝部骨关节炎（OA）的临床健康结果。
对128名在专门关节炎诊所就诊的OA患者进行访谈，了解他们的社会经济特征，并采用TTO技术和WOMAC进行评估。还调查了他们对两种假设的抗骨关节炎药物的WTP：第一种药物据说能使WOMAC维度有显著改善，第二种药物能完全治愈该疾病。通过离散选择法和投标博弈法来确定WTP。结果。TTO的回答率为89.1%，两种情况下离散选择WTP的回答率均为98.4%，缓解和治愈情况下投标博弈WTP的回答率分别为89.8%和85.2%。TTO效用值的平均值为0.84（标准差0.20）。在离散选择中，接受出价的人月收入较高（缓解情况下为1536.5欧元对1060.1欧元，p<0.001；治愈情况下为1449.3欧元对1071.6欧元，p<0.001）。采用投标博弈形式时，两种情况下WTP均与收入呈正相关（r=0.56，r=0.55，p<0.001）。教育和社会经济群体之间的WTP测量值差异相同，优势群体中的人始终报告较高的WTP（Kruskal-Wallis检验统计量范围为p<0.01至p<0.
