http://nova.newcastle.edu.au/vital/access/services/Feed ${session.getAttribute("locale")} 5 http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:5182 Objectives: To estimate indirect costs through human capital approach and intangible costs through willingness-to-pay (WTP), and identify factors potentially affecting these costs in multiethnic Asian patients with knee osteoarthritis (OA). Methods: Data were collected through face-to-face interviews among knee OA patients. Human capital approach was used to estimate indirect costs by multiplying: 1) days of absence from work because of OA, with average earnings per capita per day for working patients; or 2) productivity loss with the market price of housekeeping for retirees/homemakers. A closed-ended iterative bidding contingent valuation method was used to elicit willingness-to-pay for a hypothetical cure of OA as a proxy for intangible costs. Mann-Whitney U or Kruskal-Wallis H-tests were performed in univariate analyzes, and linear regression in multivariate analyses. Results: Indirect costs per year and intangible costs were estimated at US$1.008 and US$1200, accounting for 2.8% and 3.3% of annual household income, respectively. The indirect costs were significantly higher for male or working patients, while intangible costs were higher for Chinese, working patients, with higher income, or worse global well-being. Conclusion: This study demonstrated that eliciting indirect costs through human capital approach and intangible costs through WTP are acceptable and feasible in Asian patients with knee OA. Besides the direct costs, the indirect and intangible costs for the OA patients could be substantial. 2010-04-27T04:46:46.219Z ]]> http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:5185 Objective: Our aim was to cross-culturally validate Chinese Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) in patients with knee osteoarthritis (OA) scheduled for total knee replacement in Singapore. Methods: Chinese WOMAC was translated from the original English version following standard guidelines. Patients were asked to complete a questionnaire containing the WOMAC (twice within 6 days), the Short Form 36 (SF-36), and the EuroQoL EQ-5D. Reliability was assessed using Cronbach's alpha and intraclass correlation coefficients (ICC), dimensionality using item-to-domain correlations and factor analyses. Convergent and discriminant construct validity was assessed using six each a priori hypotheses. Results: Chinese WOMAC was well accepted by the patients in the pilot test. The Chinese and English versions were therefore administered to a consecutive sample of 131 Chinese- and 127 English-speaking subjects, respectively, with knee OA. Cronbach's alpha exceeded 0.7 for all domains except for Chinese pain domain, whereas the ICC exceeded 0.7 for all domains. Hypothesized item-to-domain correlations were observed for all items except for four items in Chinese physical function domain. The factor analyses yielded seven and five factors with eigenvalues of more than 1.0 in the Chinese and English versions, respectively. A total of 10/12 a priori construct validity hypotheses were satisfied for the Chinese version. Weak correlations between WOMAC pain and SF-36 bodily pain and moderate correlation between WOMAC pain and EQ-5D anxiety/depression were observed. Conclusions: Chinese WOMAC was well accepted and demonstrated acceptable psychometric properties in Singaporean patients with severe knee OA. 2010-04-27T04:46:42.537Z ]]>