1177 - Cost-Effectiveness of ACR Guideline-Based Care and Lifetime Direct Medical Costs Attributable to Knee OA Management in the US

Monday, October 19, 2009: 3:45 PM
112 A (Pennsylvania Convention Center)
E. Losina1, N.N. Niu2, H.L. Holt3, W.M. Reichmann3, D.J. Hunter4, L.G. Suter5, D.H. Solomon2, E.H. Yelin6, J.M. Jordan7, R.P. Walensky8, A.D. Paltiel5 and J.N. Katz2, 1Brigham and Women's Hospital, BU School of Public Health and Harvard Medical School, Boston, MA, 2Brigham and Women's Hospital and Harvard Medical School, Boston, MA, 3Brigham and Women's Hospital, Boston, MA, 4New England Baptist Hospital, Boston, MA, 5Yale University, New Haven, CT, 6UCSF, San Francisco, CA, 7University of North Carolina, Chapel Hill, NC, 8Brigham and Women's Hospital and Massachusetts General Hospital, Boston, MA
Presentation Number: 1177


Knee OA is debilitating and affects >4.5 million US adults.  ACR treatment guidelines include pain management, physical therapy (PT), NSAIDS, intra-articular steroid injections and total knee arthroplasty (TKA) for those who reach end-stage disease. There have been no studies estimating cost-effectiveness (C-E) of ACR treatment guidelines or costs attributable to knee OA.


We used a validated computer simulation model of knee OA natural history and management to follow a cohort of newly diagnosed knee OA patients (mean age 60, 54% female, 65% K-L 2, 30% K-L 3, 5% K-L 4) to death. Treatment efficacy and toxicity were derived from published literature; OA progression was derived from Johnston County Osteoarthritis Project and calibrated to published literature. Prevalence of comorbidities and quality of life estimates were derived from NHANES and mortality, from US life tables. Treatment costs were derived from Medicare reimbursement and Red Book (range: $609/yr for PT, NSAIDS, devices and capsaicin to $20,456 for TKA). The cost of background pain control was $551/yr. Costs related to other co-morbidities ranged from $557/yr for 0-1 to $3,603/yr for >3 co-morbidities. We considered four scenarios: 1) no treatment; 2) pain control only; 3) ‘ideal': 100% of patients on ACR-recommended treatment; 4) ‘real': acceptance ranging from 100% for NSAIDS, PT, capsaicin to 30% for TKA and 12% for TKA revision.  The C-E of ACR recommended treatment was estimated as the ratio of incremental cost to incremental effectiveness (expressed in quality-adjusted life years, QALYs). Costs (in 2008 $US) are reported as total direct medical costs and costs attributable to knee OA.  Both costs and QALYs were discounted at 3%/yr.  


Discounted life expectancy of persons with knee OA was 15.6 years (22.2 years, undiscounted) or 11.9 QALYs.   Background (unrelated to knee OA) medical costs were $11,862.  Pain control increased costs by $7,434 without altering QALYs. ‘Ideal' ACR guideline-based treatment yielded costs of $25,052 and improved QALYs by 0.47, yielding an incremental to ‘no treatment' cost-effectiveness ratio of $28,060/QALY.  Figure 1 illustrates average time spent, distribution of cost attributed to and proportion of original cohort on each regimen according to ‘real' scenario.


ACR guideline-based knee OA care is very cost-effective.  Lifetime costs attributable to knee OA represent a relatively small part (24%) of total direct medical costs.  Using a conservative estimate of 4.5M affected by knee OA in US, $27 billion will be spent on knee OA related care.

Keywords: economics and osteoarthritis

Disclosure: E. Losina, None; N. N. Niu, None; H. L. Holt, None; W. M. Reichmann, None; D. J. Hunter, None; L. G. Suter, None; D. H. Solomon, Amgen, 2, Abbott Immunology Pharmaceuticals, 2 ; E. H. Yelin, None; J. M. Jordan, None; R. P. Walensky, None; A. D. Paltiel, None; J. N. Katz, None.