Cram Peter, Ibrahim Said A, Lu Xin, Wolf Brian R
Department of Internal Medicine, Division of General Internal Medicine, University of Iowa Carver College of Medicine, Iowa City, IA, USA ; CADRE, Iowa City Veterans Administration Medical Center, Iowa City, IA, USA.
Geriatr Orthop Surg Rehabil. 2012 Mar;3(1):17-26. doi: 10.1177/2151458511435723.
Administrative data are commonly used to examine orthopedic outcomes including total hip arthroplasty (THA), but little is known about how minor analytic decisions impact results. Our objective was to examine how the rates of 3 adverse outcomes (deep vein thrombosis [DVT], pulmonary embolism [PE], and hemorrhage) varied with subtle adjustments to our analytic method.
We used Medicare Part A data to identify all beneficiaries who underwent primary or revision THA during 2007 to 2008. We used 2 published algorithms (Katz/Cram and Patient Safety Indicators [PSIs]) to identify cases of DVT, PE, and hemorrhage occurring at 3 different points in time; index admission; 30-day readmission; and index admission plus readmission. We used the kappa statistic to compare the agreement between methods. We examined variation in complication rates across hospitals using regression models that adjusted for differences in patient demographics and comorbidity.
Among 202 773 primary and 40 973 revision THA patients, the agreement between the Katz/Cram and PSI methods was excellent for DVT and PE at all time points (kappa 0.95-1.0) but poor for hemorrhage (kappa 0.07-0.29). The incidence of DVT during the index admission among the primary THA cohort was 0.40% using the Katz/Cram method and 0.37% using the PSI method. The incidence of hemorrhage during the index admission among the primary THA cohort was 1.29% using the Katz/Cram method and 0.05% using the PSI method. We found significant variation in hospital rates of all 3 complications (DVT, PE, and hemorrhage). For example, the mean rate of hemorrhage at index admission or readmission for revision THA was 5.7% (standard deviation: 12.8%); we found 137 hospitals with hemorrhage rates of 25% or higher among their revision THA patients.
We found important differences in the rates of THA complications depending upon the coding algorithms and time frame employed. Our results suggest that administrative data can be used to evaluate THA complications but that methodology should be carefully considered.
行政数据常用于研究包括全髋关节置换术（THA）在内的骨科手术结果，但对于微小的分析决策如何影响结果却知之甚少。我们的目的是研究对分析方法进行细微调整时，三种不良结局（深静脉血栓形成[DVT]、肺栓塞[PE]和出血）的发生率如何变化。
我们使用医疗保险A部分的数据，确定了2007年至2008年期间接受初次或翻修THA的所有受益人。我们使用两种已发表的算法（Katz/Cram和患者安全指标[PSI]）来确定在三个不同时间点发生的DVT、PE和出血病例；索引入院；30天再入院；以及索引入院加再入院。我们使用kappa统计量来比较方法之间的一致性。我们使用回归模型检查了不同医院并发症发生率的差异，该模型对患者人口统计学和合并症的差异进行了调整。
在202773例初次THA患者和40973例翻修THA患者中，Katz/Cram和PSI方法在所有时间点对DVT和PE的一致性都非常好（kappa 0.95 - 1.0），但对出血的一致性较差（kappa 0.07 - 0.29）。初次THA队列中索引入院期间DVT的发生率，使用Katz/Cram方法为0.40%，使用PSI方法为0.37%。初次THA队列中索引入院期间出血的发生率，使用Katz/Cram方法为1.29%，使用PSI方法为0.05%。我们发现所有三种并发症（DVT、PE和出血）在不同医院的发生率存在显著差异。例如，翻修THA索引入院或再入院时出血的平均发生率为5.7%（标准差：12.8%）；我们发现137家医院的翻修THA患者出血率达到或超过25%。
我们发现，根据所采用的编码算法和时间框架，THA并发症的发生率存在重要差异。我们的结果表明，行政数据可用于评估THA并发症，但应仔细考虑方法。
