Shearer David W, Youm Jiwon, Bozic Kevin J
Department of Orthopaedic Surgery, University of California, San Francisco, 500 Parnassus Avenue, MU 320-W, San Francisco, CA, 94143, USA.
Clin Orthop Relat Res. 2015 May;473(5):1702-8. doi: 10.1007/s11999-014-4110-z. Epub 2015 Jan 6.
Outcomes research in THA has focused largely on long-term implant survivorship as a primary outcome and emphasized the development of new implant technologies. In contrast, strategies to improve short-term outcomes, such as the frequencies of periprosthetic joint infections and unplanned readmissions, have received less attention.
QUESTIONS/PURPOSES: We asked whether reductions in periprosthetic joint infections and early readmissions would have greater influence on the net monetary benefit (a summation of lifetime cost and quality of life) for THA compared with equivalent reductions in aseptic loosening.
A Markov model was created using decision-analysis software with six health states and death to represent seven major potential outcomes of THA. We compared the effect of a 10% reduction in each of the following outcomes: (1) periprosthetic joint infection, (2) hospital readmission, and (3) aseptic loosening. Procedure costs (not charges) were derived from our hospital cost-accounting system. Probabilities were derived primarily from the Australian Orthopaedic Association National Joint Replacement Registry, and utilities were estimated from a previous study at our institution using the time trade-off method. The primary outcome of the study is the net monetary benefit, which combines the reductions in cost and improvement in health-related quality of life in a single metric. Quality of life is expressed in quality-adjusted life years (QALYs), which are calculated by multiplying the utility of a health state (ranging from 0 to 1) by the duration of time in the health state. The cost and QALYs are reported separately as secondary outcomes. One-way and multivariate sensitivity analyses were performed including a probabilistic sensitivity analysis to account for uncertainty in model inputs.
The net monetary benefit for a 10% reduction in periprosthetic joint infections was USD 278 (95% CI, USD 239-295) per index procedure compared with USD 174 (95% CI, USD 150-185) and USD 113 (95% CI, USD 94-129) for reductions in aseptic loosening and early readmission, respectively. Compared with the base case, reductions in cost associated with a 10% reduction in periprosthetic joint infections, early readmissions, and aseptic loosening were USD 98, USD 93, and USD 75 per index procedure, respectively. The increase in QALYs for an equivalent reduction in periprosthetic joint infections, aseptic loosening, and early readmissions were 0.0036, 0.002, and 0.0004 QALYs, respectively. Results were most sensitive to age, baseline rate of readmission, periprosthetic joint infection, aseptic loosening, and the costs of readmission and revision THA.
Strategies to reduce periprosthetic joint infections may have a greater effect on the cost and long-term effectiveness of THA than further enhancements in implant longevity. Reductions in the rate of readmission resulted in greater reductions in cost but not quality-of-life, and therefore had smaller effect on the net monetary benefit compared with aseptic loosening. Surgeons preferentially should engage in strategies focusing on periprosthetic joint infections to improve the value of THA care.
Level II, economic and decision analysis.
全髋关节置换术（THA）的疗效研究主要集中在长期植入物存活率这一主要结果上，并强调了新植入技术的发展。相比之下，改善短期结果的策略，如假体周围关节感染的发生率和意外再入院率，受到的关注较少。
问题/目的：我们探讨了与同等程度降低无菌性松动相比，降低假体周围关节感染和早期再入院率对THA的净货币效益（终身成本和生活质量的总和）是否有更大影响。
使用决策分析软件创建一个马尔可夫模型，该模型有六个健康状态和死亡状态，以代表THA的七个主要潜在结果。我们比较了以下每种结果降低10%的影响：（1）假体周围关节感染，（2）医院再入院，（3）无菌性松动。手术成本（非收费）来自我们医院的成本核算系统。概率主要来自澳大利亚骨科协会国家关节置换登记处，效用值是根据我们机构之前一项使用时间权衡法的研究估算得出的。该研究的主要结果是净货币效益，它将成本降低和与健康相关的生活质量改善结合在一个单一指标中。生活质量用质量调整生命年（QALY）表示，通过将健康状态的效用值（范围从0到1）乘以处于该健康状态的时间长度来计算。成本和QALY分别作为次要结果报告。进行了单因素和多因素敏感性分析，包括概率敏感性分析，以考虑模型输入中的不确定性。
与降低无菌性松动和早期再入院率相比，假体周围关节感染降低10%时，每个索引手术的净货币效益为278美元（95%CI，239 - 295美元），而降低无菌性松动和早期再入院率时分别为174美元（95%CI, 150 - 185美元）和113美元（95%CI, 94 - 129美元）。与基础病例相比，假体周围关节感染、早期再入院和无菌性松动分别降低10%时，每个索引手术相关成本的降低分别为98美元、93美元和75美元。假体周围关节感染、无菌性松动和早期再入院同等程度降低时，QALY的增加分别为0.0036、0.002和0.0004 QALY。结果对年龄、再入院基线率、假体周围关节感染、无菌性松动以及再入院和翻修THA的成本最为敏感。
与进一步提高植入物使用寿命相比，降低假体周围关节感染的策略可能对THA的成本和长期疗效有更大影响。再入院率的降低导致成本降低幅度更大，但对生活质量没有影响，因此与无菌性松动相比，对净货币效益的影响较小。外科医生应优先采用关注假体周围关节感染的策略，以提高THA治疗的价值。
二级，经济和决策分析。
