Predicting Outcomes During Cerebral Aneurysm Coiling
Predicting Outcomes During Cerebral Aneurysm Coiling
Background Benchmarking of complications is necessary in the context of the developing path to accountable care. We attempted to create a predictive model of negative outcomes in patients undergoing cerebral aneurysm coiling (CACo).
Methods We performed a retrospective cohort study involving patients who underwent CACo from 2005 to 2009 and who were registered in the Nationwide Inpatient Sample database. A model for outcome prediction based on individual patient characteristics was developed.
Results Of the 10 607 patients undergoing CACo, 6056 presented with unruptured aneurysms (57.1%) and 4551 with subarachnoid hemorrhage (42.9%). The respective inpatient postoperative risks were 0.3%, 5.7%, 1.8%, 0.8%, 0.5%, 0.2%, 1.9%, and 0.1% for unruptured aneurysms, and 13.8%, 52.8%, 4.9%, 36.7%, 1%, 2.9%, 2.3%, and 0.8% for ruptured aneurysms for death, unfavorable discharge, stroke, treated hydrocephalus, cardiac complications, deep vein thrombosis, pulmonary embolism, and acute renal failure. Multivariate analysis identified risk factors independently associated with the above outcomes. A validated model for outcome prediction based on individual patient characteristics was developed. The accuracy of the model was estimated by the area under the receiver operating characteristic curve, and it was found to have good discrimination.
Conclusions The presented model can aid in the prediction of the incidence of postoperative complications, and can be used as an adjunct in tailoring the treatment of cerebral aneurysms.
Since the publication of the International Study for Aneurysm Treatment, there has been a paradigm shift in the treatment of cerebral aneurysms in the USA. Cerebral aneurysm coiling (CACo) has surfaced as the predominant treatment modality, not only for subarachnoid hemorrhage (SAH), but also for elective cases, increasing the total number of aneurysms treated in recent years. This trend for more coiling of unruptured aneurysms is not based on randomized controlled trials (RCT). Even in cases of SAH, where several RCT have supported the superiority of coiling at least after 1 year of follow-up (with the Barrow Ruptured Aneurysm Trial trial demonstrating equivalence in 3 years), the rigorous inclusion criteria restrict their results in certain patients with low operative risk and predefined age range. Determination of an estimated risk of adverse events for each individual patient could tailor the application of the results of evidence based medicine and assist in decision making, especially in patients suitable for clipping and coiling. This strategy can also allow the identification of modifiable risk factors associated with postoperative medical complications in patients undergoing coiling.
Several studies have attempted to identify such complications. However, they have mostly focused on comparing those for patients undergoing clipping versus coiling. There has been no investigation of modifiable patient level risk factors that can affect outcomes. Most of the studies have been retrospective analyses of single institution experiences, demonstrating results with limited generalization given their inherent selection bias. Interpretation of other multicenter studies is equally limited given their focus on specific subgroup data or their consideration of all morbidity as one variable.
The Nationwide Inpatient Sample (NIS) is a hospital discharge database that represents approximately 20% of all inpatient admissions to non-federal hospitals in the USA. It allows for the unrestricted study of the patient population in question. Using this database, preoperative comorbidities associated with postoperative death, unfavorable discharge, stroke, treated hydrocephalus, cardiac complications, deep vein thrombosis (DVT), pulmonary embolism (PE), acute renal failure (ARF), and prolonged length of stay in patients undergoing CACo were identified. Based on these data, a risk factor based predictive model for negative outcomes in CACo was developed.
Abstract and Introduction
Abstract
Background Benchmarking of complications is necessary in the context of the developing path to accountable care. We attempted to create a predictive model of negative outcomes in patients undergoing cerebral aneurysm coiling (CACo).
Methods We performed a retrospective cohort study involving patients who underwent CACo from 2005 to 2009 and who were registered in the Nationwide Inpatient Sample database. A model for outcome prediction based on individual patient characteristics was developed.
Results Of the 10 607 patients undergoing CACo, 6056 presented with unruptured aneurysms (57.1%) and 4551 with subarachnoid hemorrhage (42.9%). The respective inpatient postoperative risks were 0.3%, 5.7%, 1.8%, 0.8%, 0.5%, 0.2%, 1.9%, and 0.1% for unruptured aneurysms, and 13.8%, 52.8%, 4.9%, 36.7%, 1%, 2.9%, 2.3%, and 0.8% for ruptured aneurysms for death, unfavorable discharge, stroke, treated hydrocephalus, cardiac complications, deep vein thrombosis, pulmonary embolism, and acute renal failure. Multivariate analysis identified risk factors independently associated with the above outcomes. A validated model for outcome prediction based on individual patient characteristics was developed. The accuracy of the model was estimated by the area under the receiver operating characteristic curve, and it was found to have good discrimination.
Conclusions The presented model can aid in the prediction of the incidence of postoperative complications, and can be used as an adjunct in tailoring the treatment of cerebral aneurysms.
Introduction
Since the publication of the International Study for Aneurysm Treatment, there has been a paradigm shift in the treatment of cerebral aneurysms in the USA. Cerebral aneurysm coiling (CACo) has surfaced as the predominant treatment modality, not only for subarachnoid hemorrhage (SAH), but also for elective cases, increasing the total number of aneurysms treated in recent years. This trend for more coiling of unruptured aneurysms is not based on randomized controlled trials (RCT). Even in cases of SAH, where several RCT have supported the superiority of coiling at least after 1 year of follow-up (with the Barrow Ruptured Aneurysm Trial trial demonstrating equivalence in 3 years), the rigorous inclusion criteria restrict their results in certain patients with low operative risk and predefined age range. Determination of an estimated risk of adverse events for each individual patient could tailor the application of the results of evidence based medicine and assist in decision making, especially in patients suitable for clipping and coiling. This strategy can also allow the identification of modifiable risk factors associated with postoperative medical complications in patients undergoing coiling.
Several studies have attempted to identify such complications. However, they have mostly focused on comparing those for patients undergoing clipping versus coiling. There has been no investigation of modifiable patient level risk factors that can affect outcomes. Most of the studies have been retrospective analyses of single institution experiences, demonstrating results with limited generalization given their inherent selection bias. Interpretation of other multicenter studies is equally limited given their focus on specific subgroup data or their consideration of all morbidity as one variable.
The Nationwide Inpatient Sample (NIS) is a hospital discharge database that represents approximately 20% of all inpatient admissions to non-federal hospitals in the USA. It allows for the unrestricted study of the patient population in question. Using this database, preoperative comorbidities associated with postoperative death, unfavorable discharge, stroke, treated hydrocephalus, cardiac complications, deep vein thrombosis (DVT), pulmonary embolism (PE), acute renal failure (ARF), and prolonged length of stay in patients undergoing CACo were identified. Based on these data, a risk factor based predictive model for negative outcomes in CACo was developed.
