Development and Validation of a Comorbidity Scoring System for Patients with Cirrhosis.
Gastroenterology. 2013 Sep 17;
Authors: Jepsen P, Vilstrup H, Lash TL
BACKGROUND: & Aims: At least 40% of patients with cirrhosis have comorbidities, which increase mortality. We developed a cirrhosis-specific comorbidity scoring system (CirCom) to help determine how these comorbidities affect mortality, and compared it with the generic Charlson Comorbidity Index.
METHODS: We used data from nationwide healthcare registries to identify Danish citizens diagnosed with cirrhosis in 1999-2008 (n=12,976). They were followed through 2010 and characterized by 34 comorbidities. We used Cox regression to assign severity weights to comorbidities with an adjusted mortality hazard ratio ≥1.20. Each patient's CirCom score was based on at most 2 of these comorbidities. Performance was measured with Harrell's C statistic and the Net Reclassification Index (NRI), and results were compared with those obtained using the Charlson index (based on 17 comorbidities). Findings were validated in 2 separate cohorts of patients with alcohol-related cirrhosis or chronic hepatitis C.
RESULTS: The CirCom score included chronic obstructive pulmonary disease, acute myocardial infarction, peripheral arterial disease, epilepsy, substance abuse, heart failure, non-metastatic cancer, metastatic cancer, and chronic kidney disease; 24.2% of patients had 1 or more of these, and mortality correlated with the CirCom score. Patients' CirCom score correlated with their Charlson Comorbidity Index (Kendall's τ = 0.57, P<.0001). Compared with the Charlson index, the CirCom score increased Harrell's C statistic by 0.6% (95% confidence interval, 0.3%-0.8%). The NRI for the CirCom score was 5.2% (95% confidence interval, 3.7%-6.9%), whereas the NRI for the Charlson index was 3.6% (95% confidence interval, 2.3%-5.0%). Similar results were obtained from the validation cohorts.
CONCLUSIONS: We developed a scoring system to predict mortality among patients with cirrhosis, based on 9 comorbidities. This system had higher C statistic and NRI values than the Charlson Comorbidity Index, and is easier to use. It could therefore be a preferred method to predict death or survival of patients and for epidemiologic studies.
PMID: 24055278 [PubMed - as supplied by publisher]