Comorbidity and survival of Danish cirrhosis patients: a nationwide population-based cohort study

Patients with liver cirrhosis have a high mortality, not just from cirrhosis-related causes, but also from other causes. This observation indicates that many patients with cirrhosis have other chronic diseases, yet the prognostic impact of comorbidities has not been examined. Using data from a nationwide Danish population-based hospital registry, we identified patients who were diagnosed with cirrhosis between 1995 and 2006 and computed their burden of comorbidity using the Charlson comorbidity index. We compared survival between comorbidity groups, adjusting for alcoholism, sex, age, and calendar period. We also examined the risks of cirrhosis-related and non-cirrhosis-related death using data from death certificates and identified a matched comparison cohort without cirrhosis from the Danish population. We included 14,976 cirrhosis patients, 38% of whom had one or more comorbidities. The overall 1-year survival probability was 65.5%; the 10-year survival probability was 21.5%. Compared with patients with a Charlson comorbidity index of 0, the mortality rate was increased 1.17-fold in patients with an index of 1 [95% confidence interval (CI), 1.11-1.23], 1.51-fold in patients with an index of 2 (95% CI, 1.42-1.62), and two-fold in patients with an index of 3 or higher (95% CI, 1.85-2.15). In the first year of follow-up, but not later, comorbidity increased the risk of cirrhosis-related death, and this was consistent with an apparent synergy between the cirrhosis and comorbidity effects on mortality in the same period.

Our findings demonstrate that comorbidity is an important prognostic factor for patients with cirrhosis. Successful treatment of comorbid diseases in the first year after diagnosis may substantially reduce the mortality rate.