Epidemiology and causes of death in a Swedish cohort of patients with autoimmune hepatitis

Abstract

Background: Epidemiological studies of autoimmune hepatitis (AIH) show varying figures on prevalence and incidence, and data on the long-term prognosis are scarce. Objective To investigate the epidemiology, long-term prognosis and causes of death in a Swedish AIH cohort.

Material and methods: Data collected from 634 AIH patients were matched to the Cause of Death Registry, and survival analyses were made. Prevalence and incidence were calculated for university hospitals with full coverage of cases and compared to the County of Västerbotten in Northern Sweden.

Results: AIH point prevalence was 17.3/100,000 inhabitants in 2009, and the yearly incidence 1990-2009 was 1.2/100,000 inhabitants and year. The time between diagnosis and end of follow-up, liver transplantation or death was in median 11.3 years (range 0-51.5 years). Men were diagnosed earlier (p < .001) and died younger than women (p = .002). No gender differences were found concerning transplant-free, overall survival and liver-related death. Cirrhosis at diagnosis was linked to an inferior survival (p < .001). Liver-related death was the most common cause of death (32.7%). The relative survival started to diverge from the general population 4 years after diagnosis but a distinct decline was not observed until after more than 10 years.

Conclusions: Long-term survival was reduced in patients with AIH. No gender difference regarding prognosis was seen but men died younger, probably as a result of earlier onset of disease. Cirrhosis at diagnosis was a risk factor for poor prognosis and the overall risk of liver-related death was increased.

Keywords: Autoimmune hepatitis; causes of death; cirrhosis; epidemiology; liver.