Recalibration and validation of the Charlson Comorbidity Index in acute kidney injury patients underwent continuous renal replacement therapy

Abstract

Background: Comorbid conditions impact the survival of patients with severe acute kidney injury (AKI) who require continuous renal replacement therapy (CRRT). The weights assigned to comorbidities in predicting survival vary based on type of index, disease, and advances in management of comorbidities. We developed a modified Charlson Comorbidity Index (CCI) for use in patients with AKI requiring CRRT (mCCI-CRRT) and improved the accuracy of risk stratification for mortality. Methods: A total of 828 patients who received CRRT between 2008 and 2013, from three university hospital cohorts was included to develop the comorbidity score. The weights of the comorbidities were recalibrated using a Cox proportional hazards model adjusted for demographic and clinical information. The modified index was validated in a university hospital cohort (n = 919) using the data of patients treated from 2009 to 2015. Results: Weights for dementia, peptic ulcer disease, any tumor, and metastatic solid tumor were used to recalibrate the mCCI-CRRT. Use of these calibrated weights achieved a 35.4% (95% confidence interval [CI], 22.1%-48.1%) higher performance than unadjusted CCI in reclassification based on continuous net reclassification improvement in logistic regression adjusted for age and sex. After additionally adjusting for hemoglobin and albumin, consistent results were found in risk reclassification, which improved by 35.9% (95% CI, 23.3%-48.5%). Conclusion:The mCCI-CRRT stratifies risk of mortality in AKI patients who require CRRT more accurately than does the original CCI, suggesting that it could serve as a preferred index for use in clinical practice.

Mortality in elderly hemodialysis patients, influence of frailty and comorbidity

“…Nonetheless, we choose two scores that are already extensively validated in hemodialysis patients. 6,10,11,[31][32][33] Finally, as one time acquisition of the scores also enables the misclassification of the patients, longitudinal evaluation of frailty and comorbidity could improve the accuracy of data collection and limit the misclassification.…”

Effects of different palliative care models on decedents with kidney failure receiving maintenance dialysis: a nationwide population-based retrospective observational study in Taiwan

“…We took several related confounding variables into consideration, including age at death, gender, low income, living in a rural area and comorbidities based on prior empirical research 51 52. Data regarding comorbidities were calculated using Charlson’s Comorbidity Index (CCI),53 a widely used comorbidity index in acute kidney injury and chronic kidney disease outcome studies 54 55. This index is the sum of weighted scores based on the presence or absence of 17 different medical conditions.…”

“… 51 52 Data regarding comorbidities were calculated using Charlson’s Comorbidity Index (CCI), 53 a widely used comorbidity index in acute kidney injury and chronic kidney disease outcome studies. 54 55 This index is the sum of weighted scores based on the presence or absence of 17 different medical conditions. The low-income qualification was regulated by Article 4 of the Public Assistance Act of Taiwan under the following conditions: (1) individuals are approved by their local municipality’s competent authority via application, (2) the average divided monthly income among each person in the household falls below the lowest living index and (3) total household assets do not exceed the specified amount announced by both the central and municipality competent authorities in the year of application.…”

“…51 52 Data regarding comorbidities were calculated using Charlson's Comorbidity Index (CCI), 53 a widely used comorbidity index in acute kidney injury and chronic kidney disease outcome studies. 54 55…”