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A population-based nested case-control study of the costs of hip and knee replacement surgery


Background — Studies of total joint arthroplasty (TJA) have not evaluated the costs and outcomes in the context of expected arthritis worsening.

Objectives — Using a cost-consequence approach, to examine changes in direct healthcare costs and arthritis severity after TJA for hip/knee arthritis compared with contemporaneous changes in matched controls.

Research Design — Case control study nested in a population-based prospective cohort.

Subjects — In a population cohort with disabling hip/knee osteoarthritis followed from 1996 to 2003, primary TJA recipients were matched with cohort nonrecipients on age, sex, region of residence, comorbidity, and inflammatory arthritis diagnosis.

Measures — Pre- and postoperative total and arthritis-attributable direct healthcare costs, arthritis severity, and general health status were compared for cases and matched controls.

Results — Of 2109 participants with no prebaseline TJA, 185 cases received a single elective TJA during the follow-up period; of these, 183 cases and controls were successfully matched. Mean age was 71 years, 77.6% were female, 35.5% had ≥2 comorbidities, and 81.5% had ≥2 joints affected. At baseline, controls had less pain and disability and lower total and arthritis-attributable healthcare costs than cases. After surgery, although overall healthcare utilization was unchanged, cases experienced significant decreases in arthritis-attributable costs (mean decrease $278 including prescription drugs) and pain and disability (P < 0.0001 for all). Over the same time period, controls experienced a significant increase in total healthcare costs (mean increase $1978 including prescription drugs, P = 0.04) and no change or worsening of their arthritis status.

Conclusion — Compared with matched controls, arthroplasty is associated with significant reductions in pain, disability, and arthritis-attributable direct costs.



Hawker GA, Badley EM, Croxford R, Coyte PC, Glazier RH, Guan J, Harvey BJ, Williams JI, Wright JG. Med Care. 2009; 47(7):732-41.