@article {Waimannjrheum.151301, author = {Christian A. Waimann and Rodrigo J. Fernandez-Mazarambroz and Scott B. Cantor and Maria A. Lopez-Olivo and Andrea G. Barbo and Glenn C. Landon and Sherwin J. Siff and Heather Lin and Maria E. Suarez-Almazor}, title = {Effect of Body Mass Index and Psychosocial Traits on Total Knee Replacement Costs in Patients with Osteoarthritis}, elocation-id = {jrheum.151301}, year = {2016}, doi = {10.3899/jrheum.151301}, publisher = {The Journal of Rheumatology}, abstract = {Objective Clinical and psychosocial attributes are associated with clinical outcomes after total knee replacement (TKR) surgery in patients with osteoarthritis (OA), but their relationship with TKR-related costs is less clear. Our objective was to evaluate the effect of clinical and psychosocial attributes on TKR costs. Methods We conducted a 6-month prospective cohort study of patients with knee OA who underwent TKR. We examined baseline demographic, clinical [body mass index (BMI) and comorbidities], and psychosocial attributes (social support, locus of control, coping, depression, anxiety, stress, and self-efficacy); baseline and 6-month OA clinical outcomes [Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain and function]; and 6-month direct and indirect TKR-related costs. Multiple regression was performed to identify determinants of TKR-related costs. Results We included 212 patients; 66\% were women, 71\% were white, and the mean age was 65.2 years. The mean baseline WOMAC pain score was 55 (SD 19) and WOMAC function score was 54 (SD 20). Mean total TKR-related costs were US$30,831 (SD $9893). Multivariate regression analyses showed that increasing BMI and anxiety levels and decreasing levels of positive social interactions were associated with increased costs. A lower cost scenario with a lower range of normal BMI (19.5), highest positive social interaction, and no anxiety predicted TKR costs to be $22,247. Predicted costs in obese patients (BMI 36) with lowest positive social interaction and highest anxiety were $58,447. Conclusion Increased baseline BMI, anxiety, and poor social support lead to higher TKR-related costs in patients with knee OA. Preoperative interventions targeting these factors may reduce TKR-related costs, and therefore be cost-effective.}, issn = {0315-162X}, URL = {https://www.jrheum.org/content/early/2016/06/09/jrheum.151301}, eprint = {https://www.jrheum.org/content/early/2016/06/09/jrheum.151301.full.pdf}, journal = {The Journal of Rheumatology} }