1.4　Mortality

Previous surveys exploring the survival of CP patients indicate the life expectancy of these patients is reduced significantly comparing with the general population.It is estimated that the median survival time is about 15-20 years since the onset of CP.A study was conducted among 174 CP patients（95%were smokers）to explore the survival rates and cause of death（Pedrazzoli et al.2008）.The result showed the mortality rate was increased from 15.3%for 5 years to 76.5%for 30 years，and the median survival time was 15.5 years.The death of CP patients is mainly caused（60%-75%）by the extrapancreatic consequences of alcohol and smoking over use rather than CP by itself（Levy et al.2014）.The survival time of patients with alcohol-related pancreatitis is significantly shorter than the general population，but the mortality risk was not different between those with hereditary pancreatitis and the general population（Pedrazzoli et al.2008；Cavallini et al.1998；Rebours et al.2009）.(https://www.daowen.com)