Epidemiology of liver cirrhosis morbitity and mortality in Iceland.

BACKGROUND: The mortality from liver cirrhosis in Iceland is the lowest in the Western world. OBJECTIVE: To study the epidemiology of liver cirrhosis mortality and morbitity in Iceland and to obtain a reliable separation between alcoholic cirrhosis (AC) and non alcoholic cirrhosis (NAC) by using multiple data sources. METHODS: The study included the whole population of Iceland. Mortality was studied through death certificate data for the period 1951-1990 and morbidity (clinical incidence) through hospital, autopsy and biopsy records for the period 1971-1990. RESULTS: 1) The average mortality for AC in age group 20 years and older was 8.6 and for NAC 19.2 per 106 per year and the average clinical incidence was 22.1 for AC and 25.9 for NAC. 2) In the morbitity study 44% were due to AC. In the mortality study 24% were due to AC but the data suggested an underreporting of AC for males at a rate of 30%. 3) There was a significant decrease in AC mortality with time but no change in NAC. 4) Alcohol consumption per inhabitant over 15 years increased from 2.1 to 4.9 litre (130%) during the period 1951-1990. CONCLUSION: The incidence of cirrhosis in Iceland is very low for both AC and NAC accounting for only 0.2% of total deaths. The reasons are unknown. The low incidence of AC in Iceland is probably partly due to a low population alcohol consumption. The decreasing incidence of AC despite 130% increase in alcohol consumption is thought to be due to intensive treatment of alcoholism. A low prevalence of hepatitis B and C probably contributes to the low incidence of NAC.