Two-stage revisions of total hip arthroplasties complicated by chronic infection result in reinfection rates that are lower than those following single-stage revisions but may also result in increased surgical morbidity. Using a decision analysis, we compared single-stage and two-stage revisions to determine which treatment modality resulted in greater quality-adjusted life years (QALYs).
A review of the literature on the treatment of patients with an infection at the site of a total hip arthroplasty provided probabilities; utility values for common postoperative health states were determined in a previously published study. With these data, we conducted a Markov cohort simulation decision analysis. Sensitivity analysis validated the model, and comparisons were made in terms of QALYs.
The twelve-month model favored direct-exchange revision over the two-stage approach, regardless of whether surgeon or patient-derived utilities were used (0.945 versus 0.896 and 0.897 versus 0.861 QALYs for the patient and surgeon models, respectively). Similar results were observed in a lifetime model with a ten-year life expectancy (7.853 versus 7.771, and 7.438 versus 7.362 QALYs, respectively). The findings were found to be robust in sensitivity analyses in which clinically relevant ranges of input variables were used.
This analysis favored the direct-exchange arthroplasty over the two-stage approach. This study should be considered hypothesis-generating for future randomized controlled trials in which, ideally, health end points will be considered in addition to the eradication of infection.
Economic and decision analysis Level II. See Instructions to Authors for a complete description of levels of evidence.
1Department of Orthopaedics and Sports Medicine, University of Washington, Box 356500, 1959 N.E. Pacific Street, Seattle, WA 98195
2Pharmerit North America, LLC, 4350 East West Highway, Suite 430, Bethesda, MD 20814. E-mail address: email@example.com
3School of Pharmacy, University of Southern California, 1540 East Alcazar Street, CHP-140, Los Angeles, CA 90089-9004