Zhu Haifeng, Hill Michael D
Department of Clinical Neurosciences, University of Calgary, Foothills Hospital, Rm 1242A, 1403 29th Street NW, Calgary, Alberta, Canada T2N 2T9.
Neurology. 2008 Jul 22;71(4):283-7. doi: 10.1212/01.wnl.0000318278.41347.94.
Adjustment for comorbidity is an important component of any clinical outcome study using administrative data. The Elixhauser Index is a relatively newer comorbidity index for use with administrative data and has not been used to assess prognosis in patients with stroke. Similarly, an International Classification of Diseases (ICD)-10 coding algorithm has been rarely reported for Elixhauser Index.
To evaluate whether the Elixhauser Index provides a useful comorbidity adjustment for predicting in-hospital case-fatality in stroke outcome studies and to compare the degree of consistency using ICD-9-CM and ICD-10 coding algorithms.
Patients who had stroke from 1998 to 2000 (cohort A in the ICD-9-CM data) and 2003 to 2005 (cohort B in the ICD-10 data) in a large Canadian city were identified from the Hospital Discharge database. The performance of two coding algorithms for predicting the in-hospital case-fatality was assessed using multivariable logistic regression models. The C-statistic was used to compare the performance of each coding algorithm in predicting in-hospital case-fatality.
Among 2,465 patients with stroke in the ICD-9-CM data (cohort A) and 2,987 patients with stroke in the ICD-10 data (cohort B), there was no difference in model performance using ICD-9-CM (C-statistic was 0.717) as compared with ICD-10 coding algorithms (C-statistic was 0.721; p = 0.83). Elixhauser comorbidity adjustment provided a better prediction of in-hospital case-fatality compared to reduced models including only age and gender (p < 0.0001) for both coding models.
The Elixhauser Index provides similar comorbidity adjusted risk estimates using both ICD-9-CM and ICD-10, and may be useful for predicting risk-adjusted in-hospital case-fatality in stroke outcome studies.
在任何使用行政数据的临床结局研究中，合并症的调整都是一个重要组成部分。埃利克斯豪泽指数是一种相对较新的用于行政数据的合并症指数，尚未用于评估中风患者的预后。同样，国际疾病分类（ICD）-10编码算法在埃利克斯豪泽指数方面的报道也很少。
评估埃利克斯豪泽指数在中风结局研究中预测院内病死率时是否能提供有用的合并症调整，并比较使用ICD-9-CM和ICD-10编码算法时的一致性程度。
从加拿大一个大城市的医院出院数据库中识别出1998年至2000年（ICD-9-CM数据中的队列A）以及2003年至2005年（ICD-10数据中的队列B）发生中风的患者。使用多变量逻辑回归模型评估两种编码算法预测院内病死率的性能。C统计量用于比较每种编码算法在预测院内病死率方面的性能。
在ICD-9-CM数据中的2465例中风患者（队列A）和ICD-10数据中的2987例中风患者（队列B）中，与ICD-10编码算法（C统计量为0.721；p = 0.83）相比，使用ICD-9-CM（C统计量为0.717）时模型性能没有差异。与仅包括年龄和性别的简化模型相比，埃利克斯豪泽合并症调整对两种编码模型的院内病死率都提供了更好的预测（p < 0.0001）。
埃利克斯豪泽指数使用ICD-9-CM和ICD-10提供了相似的合并症调整风险估计，并且可能有助于预测中风结局研究中风险调整后的院内病死率。
