In this study, the investigator would conduct an ambispective cohort study to build a prediction model of HCV-related disease after DAAs.

The emergence of direct antiviral agents (DAAs) makes it possible to cure HCV, and the sustained virological response (SVR) rate is up to 90% after DAAs therapy. However, the acquisition of SVR does not mean the cure of HCV-related diseases, some patients still developed liver cirrhosis, liver cancer and other diseases after achived SVR by DAAs therapy.In this study the investigator would like to bulid a prediction model of HCV-related disease after DAAs by conducting an ambispective cohort study. The participants of this study would be adult patients (≥18 years old) with chronic HCV infection and have received DAA therapy, the investigator would retrospectively collected DAA therapy-related information, and follow-up all the enrolled participants every 6 months to observe their liver-related disease outcomes (composite liver outcome, including liver-related deaths, hepatocellular carcinoma, liver decompensation, and liver transplantation).

Inclusion Criteria:

• adult patients (≥18 years old) with chronic HCV infection that were HCV RNA positive;
• have received DAA treatment;
• would like to adhere to the follow-up

Exclusion Criteria:

• lack of HCV treatment information;

Adult patients (≥18 years old) with chronic HCV infection that were HCV RNA positive and have received DAA therapy were included, former hcv treatment information and sustained virologic response data were collected restropectively, liver-related events including liver-related deaths, HCC, liver decompensation, and liver transplantation were collected restropectively and prospectively.