RESUMO
The potential added costs of managing fibromyalgia patients after total knee arthroplasty (TKA) have not been assessed. Therefore, the purpose of this study was to perform a cost analysis of fibromyalgia versus nonfibromyalgia patients who underwent TKA. Specifically, we evaluated the following episodes of care: (1) readmission rates, (2) total costs, (3) total reimbursements, and (4) net losses for surgical and medical complications. Patients who underwent TKAs between 2005 and 2014 from the Medicare Standard Analytical Files of the PearlDiver supercomputer were propensity score matched by patients with and without fibromyalgia in a 1:1 ratio based on age, sex, and the Charlson Comorbidity Index, yielding a total of 305,510 patients distributed equally between the cohorts for analysis. Odds ratios (ORs), 95% confidence intervals (CIs), and p-values were calculated. Mean costs, total costs, and total reimbursements were assessed as along with total net losses, which were defined as total costs minus total reimbursements. Fibromyalgia patients had similar 90-day readmission rates compared with nonfibromyalgia patients (OR: 1.03; 95% CI: 1.00-1.06; p = 0.06) but incurred lower readmission costs (US$2,318,384,295 vs. US$2,534,482,404; p < 0.001). Although fibromyalgia patients had higher total reimbursements for medical complications ($27,758,057 vs. US$18,780,610; p < 0.001), the increased management costs (US$106,049,870 vs. US$66,080,469; p < 0.001) led to greater net losses (US$78,291,813 vs. US$47,299,859; p < 0.001). Similarly, although fibromyalgia patients had higher total reimbursements for surgical complications (US$94,192,334 vs. US$73,969,026; p < 0.001), the increased surgical costs (US$382,122,613 vs. US$306,359,910; p < 0.001) led to greater net losses (US$287,930,279 vs. US$232,390,884; p < 0.001). This study highlights some of the potential financial discrepancies of managing patients with fibromyalgia. Our findings suggest medical and surgical complication costs to be greater than reimbursement, resulting in overall net financial losses. These findings need to be considered in the light of health care reform and cost structuring.
