DOCUMENTS

papers

Coding algorithms for defining comorbidities in ICD-9-CM and ICD-10 administrative data

Published: November 1, 2005
Category: Papers
Authors: Beck CA, Burnand B, Feasby TE, Fong A, Ghali WA, Halfon P, Luthi JC, Quan H, Saunders LD, Sundararajan V
Country: Canada
Language: null
Type: Care Management
Setting: Academic

Med Care 43:1130-1139.

Department of Community Health Sciences, University of Calgary, Calgary, AB, Canada

OBJECTIVES: Implementation of the International Statistical Classification of Disease and Related Health Problems, 10th Revision (ICD-10) coding system presents challenges for using administrative data. Recognizing this, we conducted a multistep process to develop ICD-10 coding algorithms to define Charlson and Elixhauser comorbidities in administrative data and assess the performance of the resulting algorithms.

METHODS: ICD-10 coding algorithms were developed by “translation” of the ICD-9-CM codes constituting Deyo’s (for Charlson comorbidities) and Elixhauser’s coding algorithms and by physicians’ assessment of the face-validity of selected ICD-10 codes. The process of carefully developing ICD-10 algorithms also produced modified and enhanced ICD-9-CM coding algorithms for the Charlson and Elixhauser comorbidities. We then used data on in-patients aged 18 years and older in ICD-9-CM and ICD-10 administrative hospital discharge data from a Canadian health region to assess the comorbidity frequencies and mortality prediction achieved by the original ICD-9-CM algorithms, the enhanced ICD-9-CM algorithms, and the new ICD-10 coding algorithms.

RESULTS: Among 56,585 patients in the ICD-9-CM data and 58,805 patients in the ICD-10 data, frequencies of the 17 Charlson comorbidities and the 30 Elixhauser comorbidities remained generally similar across algorithms. The new ICD-10 and enhanced ICD-9-CM coding algorithms either matched or outperformed the original Deyo and Elixhauser ICD-9-CM coding algorithms in predicting in-hospital mortality. The C-statistic was 0.842 for Deyo’s ICD-9-CM coding algorithm, 0.860 for the ICD-10 coding algorithm, and 0.859 for the enhanced ICD-9-CM coding algorithm, 0.868 for the original Elixhauser ICD-9-CM coding algorithm, 0.870 for the ICD-10 coding algorithm and 0.878 for the enhanced ICD-9-CM coding algorithm.

CONCLUSIONS: These newly developed ICD-10 and ICD-9-CM comorbidity coding algorithms produce similar estimates of comorbidity prevalence in administrative data, and may outperform existing ICD-9-CM coding algorithms.

PMID: 16224307

Co-morbidity,Resource Use,Performance Assessment,Canada,Canada/epidemiology,Disease/classification,Hospital Mortality,Medical Records/classification,Gender,Middle Aged,Models,Statistical,Risk Adjustment

Please log in/register to access.

Log in/Register

© The Johns Hopkins University, The Johns Hopkins Hospital, and Johns Hopkins Health System.
All rights reserved. Terms of Use Privacy Statement

Back to top