Impact of Serious Infection on Mortality of Patients With Chronic Liver Disease: A Nationwide Population-based Cohort Study

Background & Aims: This study aimed to investigate the impact of serious infection on mortality of patients with chronic liver disease (CLD). Methods: This study was conducted on 1,699,159 patients with CLD from the Korean National Health Insurance Service between 2009 and 2021. Serious infection was defined as acute meningitis, acute osteomyelitis, bacteremia, pneumonia, pyelonephritis, serious gastrointestinal infection, skin and soft tissue infections, spontaneous bacterial peritonitis, or COVID-19 infection. The primary outcome was all-cause mortality stratified by serious infection episodes (0, 1, and ≥2). Results: The mean age of patients was 57.4 years, with 55.6% being men. Among them, the proportion of CLD without cirrhosis, compensated cirrhosis, and decompensated cirrhosis was 77.5% (n = 1,317,468), 17.5% (n = 296,617), and 5.0% (n = 85,074), respectively. During follow-up, there were 336,602 episodes of serious infections, with pneumonia being the most common, followed by serious gastrointestinal infection, pyelonephritis, and bacteremia. Mortality rates were 3.94, 41.58, and 114.03 per 1000 person-years in patients with 0, 1, and ≥2 serious infections, respectively. Multivariable analysis indicated that adjusted hazard ratios (aHRs) for mortality were 6.04 (95% confidence interval [CI], 5.96–6.13) for 1 infection and 13.40 (95% CI, 13.20–13.60) for ≥2 infections, compared with no infections. Compared with CLD without cirrhosis, the development of serious infection was higher in compensated cirrhosis (aHR, 1.99; 95% CI, 1.97–2.02) and decompensated cirrhosis (aHR, 3.31; 95% CI, 3.26–3.37). Conclusions: Patients with CLD exhibited a trend of increased mortality dependent on the number of serious infections and the degree of disease severity of CLD, ranging from CLD without cirrhosis, compensated cirrhosis, and decompensated cirrhosis. Decompensated cirrhosis has more than a 3-fold risk of infection than CLD without cirrhosis.