Haifeng Zhu1, Michael D Hill. 1. Department of Clinical Neurosciences, University of Calgary, Foothills Hospital, Rm 1242A, 1403 29th Street NW, Calgary, Alberta, Canada T2N 2T9.
Abstract
BACKGROUND: 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. OBJECTIVE: 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. METHODS: 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. RESULTS: 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. CONCLUSION: 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.
BACKGROUND: 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. OBJECTIVE: 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. METHODS: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. RESULTS: 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. CONCLUSION: 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.
Authors: Shouri Lahiri; Stephan A Mayer; Matthew E Fink; Aaron S Lord; Axel Rosengart; Halinder S Mangat; Alan Z Segal; Jan Claassen; Hooman Kamel Journal: Neurocrit Care Date: 2015-08 Impact factor: 3.210
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Authors: Eric E Smith; Nandavar Shobha; David Dai; DaiWai M Olson; Mathew J Reeves; Jeffrey L Saver; Adrian F Hernandez; Eric D Peterson; Gregg C Fonarow; Lee H Schwamm Journal: J Am Heart Assoc Date: 2013-01-28 Impact factor: 5.501