Factors That Predict Short-term Complication Rates After Total Hip Arthroplasty

417

292

Background Scores derived from comorbidities can help with risk adjustment of quality and safety data. The Charlson and Elixhauser comorbidity measures are wellknown risk adjustment models, yet the optimal score for orthopaedic patients remains unclear. Questions/purposes We determined whether there was a difference in the accuracy of the Charlson and Elixhauser comorbidity-based measures in predicting (1) in-hospital mortality after major orthopaedic surgery, (2) in-hospital adverse events, and (3) nonroutine discharge. Methods Among an estimated 14,007,813 patients undergoing orthopaedic surgery identified in the National Hospital Discharge Survey (1990Survey ( -2007, 0.80% died in the hospital. The association of each Charlson comorbidity measure and Elixhauser comorbidity measure with mortality was assessed in bivariate analysis. Two main multivariable logistic regression models were constructed, with in-hospital mortality as the dependent variable and one of the two comorbidity-based measures (and age, sex, and year of surgery) as independent variables. A base model that included only age, sex, and year of surgery also was evaluated. The discriminative ability of the models was quantified using the area under the receiver operating characteristic curve (AUC). The AUC quantifies the ability of our models to assign a high probability of mortality to patients who die. Values range from 0.50 to 1.0, with 0.50 indicating no ability to discriminate and 1.0 indicating perfect discrimination. Results Elixhauser comorbidity adjustment provided a better prediction of in-hospital case mortality (AUC, 0.86; 95% CI, 0.86-0.86) compared with the Charlson model (AUC, 0.83; 95% CI, and to the base model with no comorbidities (AUC, 0.81; 95% CI, 0.81-0.81). In terms of relative improvement in predictive performance, the Elixhauser measure performed 60% better than the Charlson score in predicting mortality. The Elixhauser model discriminated inpatient morbidity better than the Charlson measure, but the discriminative ability of the model was poor and the difference in the absolute improvement in predictive power between the two models (AUC, 0.01) is of dubious clinical importance. Both comorbidity models exhibited the same degree of discrimination for estimating nonroutine discharge (AUC, 0.81; 95% CI, 0.81-0.82 for both models). Conclusions Provider-specific outcomes, particularly inpatient mortality, may be evaluated differently depending on the comorbidity risk adjustment model selected. Future research assessing and comparing the performance of the

Section: Introductionmentioning

confidence: 99%

The Elixhauser Comorbidity Method Outperforms the Charlson Index in Predicting Inpatient Death After Orthopaedic Surgery

Menendez

Neuhaus

Dijk

et al. 2014

417

292

“…In orthopaedic surgery, comorbidities have been identified as predictors of mortality after arthroplasty, trauma surgery, and oncologic surgery [4,9,18,20,21,25,27,36]. Complications after ankle fractures, spinal metastasis surgery, and knee or hip arthroplasty also are associated with comorbidities [2,12,[31][32][33][34] as are infections after orthopaedic trauma, spine surgery, knee or hip arthroplasty [8,17,22,36], and transfusion after knee or shoulder arthroplasty [12,29].…”

Section: Introductionmentioning

confidence: 99%

“…A higher CCI indicates a higher risk of death within 1 year. The CCI also has been evaluated as a predictor for outcomes after orthopaedic trauma surgery, postoperative adverse events after general surgery, and readmission for geriatric and general medicine patients [2,9,17,30,[32][33][34]37].…”

Section: Introductionmentioning

confidence: 99%

Higher Charlson Comorbidity Index Scores are Associated With Readmission After Orthopaedic Surgery

Voskuijl

Hageman

Ring

2014

169

Background The Charlson Comorbidity Index (CCI) originally was developed to predict mortality within 1 year of hospital admission in patients without trauma. As it includes factors associated with medical and surgical complexities, it also may be useful as a predictive tool for hospital readmission after orthopaedic surgery, but to our knowledge, this has not been studied. Questions/purposes We asked whether an increased score on the CCI was associated with (1) readmission, (2) an increased risk of surgical site infection or other adverse events, (3) transfusion risk, or (4) mortality after orthopaedic surgery. Methods A total of 30,129 orthopaedic surgeries performed between 2008 and 2011 without any orthopaedic surgery in the preceding 30 days were analyzed. International Classification of Diseases, 9 th Revision codes were used to identify diagnoses, procedures, surgery-related adverse events, surgical site infection, and comorbidities as listed in the updated and reweighted CCI. A total of 913 patients (3.0%) were readmitted within 30 days after discharge; in 393 (1.4%) patients adverse events occurred; 417 patients (1.4%) had a surgical site infection develop; 211 (0.7%) needed transfusions, and 56 (0.2%) died within 30 days after surgery. Ordinary least squares regression analyses were used to determine whether the CCI was associated with these outcomes. Results The CCI accounted for 10% of the variation in readmissions. Every point increase in CCI score added an additional 0.45% risk in readmission for patients undergoing arthroplasty, 0.63% for patients undergoing trauma surgery, and 0.9% risk for patients undergoing spine surgery (all p \ 0.01). The CCI was not associated with surgical site infection or other adverse events, but accounted for 8% of the variation in transfusion rate and 10% of the variation in mortality within 30 days of surgery. Conclusions The CCI can be used to estimate the risk of readmission after arthroplasty, hand and upper extremity surgery, spine surgery, and trauma surgery. It also can be used to estimate the risk of transfusion after arthroplasty, spine, trauma, and oncologic orthopaedic surgery and the risk of mortality after shoulder, trauma, and oncologic orthopaedic surgery.

“…High ASA scores have been shown to be associated with an increased risk of medical complications [30,36], prosthesis dislocation [2,23,26,28], infection [4,9,25,27,33,41,43,45,50,57], prolonged hospital stay [6,17,29], and discharge to a rehabilitation service [15] after hip and knee arthroplasties.…”

Section: Introductionmentioning

confidence: 99%

Does Preoperative American Society of Anesthesiologists Score Relate to Complications After Total Shoulder Arthroplasty?

Johnson

Sodha

Garzon-Muvdi

et al. 2014