JMIR Publications

ABSTRACT

Background:

Hepatitis A outbreaks in the United Kingdom are uncommon. Most people develop mild-to-moderate symptoms that resolve, without sequelae, within months. However, in high-risk groups, including those with underlying chronic liver disease, hepatitis A infection can be severe, with higher risk of mortality and morbidity. The UK’s public health body, the Health Security Agency and the English guidelines organisation, the National Institute of Health and Care Excellence, recommend pre-exposure hepatitis A vaccination given as two doses to people with chronic liver disease, regardless of its cause. There are currently no published reports of vaccination coverage in people with chronic liver disease in England, or internationally.

Objective:

To describe hepatitis A vaccination coverage in adults with chronic liver disease in a UK primary care setting. To compare liver disease aetiology, sociodemographic characteristics and comorbidities in people who are and are not exposed to hepatitis A vaccine.

Methods:

This is a retrospective cohort study with data from the Primary Care Sentinel Cohort of the Oxford-Royal College of General Practitioners Clinical Informatics Digital Hub (ORCHID) database; nationally representative of the English population. We will include people 18 years of age and older who have been registered in general practices in the RSC network and have a record of chronic liver disease between 01-01-2012 and 31-12-2022, including those with alcohol related liver disease, chronic hepatitis B, chronic hepatitis C, non-alcohol fatty liver disease, Wilson’s disease, haemochromatosis, and autoimmune hepatitis. We will carefully curate variables using the Systematized Nomenclature of Medicine Clinical Terms. We will report the sociodemographic characteristics of those who are vaccinated. These include: age, gender, ethnicity, population density, region, socioeconomic status (measured using the index of multiple deprivation), obesity, alcohol consumption and smoking. Hepatitis A vaccination coverage for one and two doses will be calculated using an estimate of the chronic liver disease population as the denominator. We will analyse the baseline characteristics using descriptive statistics including measures of dispersion. Pairwise comparisons of case-mix characteristics, comorbidities and complications will be reported according to vaccination status. A multistate survival model will be fitted to estimate the transition probabilities between four states: 1) Diagnosed with CLD, 2) First dose of hepatitis A vaccination, 3) Second dose of hepatitis A vaccination, 4) Death. This will identify any potential disparities in which people with chronic liver disease get vaccinated.

Results:

The RSC population comprises over 8 million people. The reported incidence of chronic liver disease is 20.7 cases per 100,000. International estimates of Hepatitis A vaccine coverage vary between 10 to 50% in this group.

Conclusions:

This study will describe the uptake of hepatitis A vaccine in people with CLD and report any disparities or differences in characteristics of the vaccinated population. Clinical Trial: Not Applicable