Background & Aims
The long-term mortality of patients infected with hepatitis C virus (HCV) is not known; few studies have controlled for potential confounders, investigated how mortality changes with age at diagnosis and length of follow-up period, provided absolute risk estimates of death, or analyzed specific causes of death.

Methods
Using a Danish population, we compared mortality of a cohort of 10,991 HCV-infected patients with that of an age- and sex-matched cohort. Using regression analysis, we adjusted for municipality of residence, history of psychiatric illness, comorbidities, alcohol and drug abuse, and income. We analyzed causes of death and effects of HCV with age and length of follow-up period.

Results
HCV-infected patients had lower income levels and more comorbidities, psychiatric illnesses, and substance and alcohol abuse than the comparison cohort. The 10-year survival rate decreased from 84.1% among HCV-infected patients aged 20 to 29 years to 21.1% among those aged 70 years or older. The increased risk of death among HCV-infected patients was more pronounced in the first year of follow-up period than in subsequent years and in the unadjusted than in the adjusted analysis. Starting in the second year of the follow-up period, HCV-infected patients aged 20 to 29 years had an 18.2-fold increased risk of death, whereas those that were 70 years or older had a 1.6-fold increased risk. Most deaths among younger patients were from unnatural causes, and most deaths among patients 70 years or older were from non–liver-related natural causes.

Conclusions
HCV infection is associated with increased mortality; younger patients (age, 20–29 y) have an increased risk of unnatural death.