Incidence, aetiology and related comorbidities of cirrhosis: a Swedish population-based cohort study

Background The incidence of cirrhosis for individuals in Sweden has previously been reported as stable/low among European countries. However, Swedish population-based studies are scarce and none of them included data from the most recent decade (2010-2019). We aimed to describe the incidence and aetiology of cirrhosis in the Halland region from 2011 to 2018, and to describe the severity and prevalence of liver-related complications and other primary comorbidities at the time of cirrhosis diagnosis. Methods We conducted a retrospective cohort study of all patients with cirrhosis in Halland, which has a population of 310,000 inhabitants. Medical records and histopathology registries were reviewed. Results A total of 598 patients with cirrhosis were identified. The age-standardised incidence was estimated at 23.2 per 100,000 person-years (95% CI 21.3-25.1), 30.5 (95% CI 27.5-33.8) for men and 16.4 (95% CI 14.3-18.7) for women. When stratified by age, the highest incidence rates were registered at age 60-69 years. Men had a higher incidence rate for most age groups when compared to women. The most common aetiology was alcohol (50.5%), followed by cryptogenic cirrhosis (14.5%), hepatitis C (13.4%), and non-alcoholic fatty liver disease (5.7%). Most patients had at least one liver-related complication at diagnosis (68%). The most common comorbidities at diagnosis were arterial hypertension (33%), type 2 diabetes (29%) and obesity (24%). Conclusions Based on previous Swedish studies, our results indicate that the incidence of cirrhosis in Sweden might be considerably higher than previously reported. It is uncertain if the incidence of cirrhosis has previously been underestimated or if an actual increment has occurred during the course of the most recent decade. The increased incidence rates of cirrhosis reported in Halland are multifactorial and most likely related to higher incidence rates among the elderly. Pre-obesity and obesity are common in cirrhosis and non-alcoholic fatty liver disease has become an important cause of cirrhosis in Halland.