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Research article:

Adaptation and validation of the Charlson Index for Read/OXMIS coded databases

Reference:

Nada F Khan, Rafael Perera, Stephen Harper, Peter W Rose(2010) Adaptation and validation of the Charlson Index for Read/OXMIS coded databases. BMC Family Practice, doi: 10.1186/1471-2296-11-1

Link to fulltext article
http://www.biomedcentral.com/1471-2296/11/1/
Abstract
Background The Charlson comorbidity index is widely used in ICD-9 administrative data, however, there is no translation for Read/OXMIS coded data despite increasing use of the General Practice Research Database (GPRD). Our main objective was to translate the Charlson index for use with Read/OXMIS coded data such as the GPRD and test its association with mortality. We also aimed to provide a version of the comorbidity index for other researchers using similar datasets. Methods Two clinicians translated the Charlson index into Read/OXMIS codes. We tested the association between comorbidity score and increased mortality in 146 441 patients from the GPRD using proportional hazards models. Results This Read/OXMIS translation of the Charlson index contains 3156 codes. Our validation showed a strong positive association between Charlson score and age. Cox proportional models show a positive increasing association with mortality and Charlson score. The discrimination of the logistic regression model for mortality was good (AUC = 0.853). Conclusion We have translated a commonly used comorbidity index into Read/OXMIS for use in UK primary care databases. The translated index showed a good discrimination in our study population. This is the first study to develop a co-morbidity index for use with the Read/OXMIS coding system and the GPRD. A copy of the co-morbidity index is provided for other researchers using similar databases.
Author for correspondence
Nada F Khan
Email for correspondence
nada.khan@dphpc.ox.ac.uk

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1 comment has been posted.

April 22, 2015, 8:52 a.m. - David Springate

This entry contains the Read/OXMIS code lists used to define the Charlson Index.

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