Socioeconomic inequalities in the incidence of alcohol-related liver disease: A nationwide Danish study

Background: There is socio-economic inequality in total alcohol-related harm, but knowledge of inequality in the incidence of specific alcohol-related diseases would be beneficial for prevention. Registry-based studies with nationwide coverage may reveal the full burden of socioeconomic inequality compared to what can be captured in questionnaire-based studies. We examined the incidence of alcohol-related liver disease (ALD) according to socioeconomic status and age. Methods: We used national registries to identify patients with an incident diagnosis of ALD and their socio-economic status in 2009-2018 in Denmark. We computed ALD incidence rates by socioeconomic status (education and employment status) and age-group (30-39, 40-49, 50-59, 60-69 years) and quantified the inequalities as the absolute and relative difference in incidence rates between low and high socioeconomic status. Findings: Of 17,473 patients with newly diagnosed ALD, 78% of whom had cirrhosis, 86% had a low or medium-low educational level and only 20% were employed. ALD patients were less likely to be employed in the 10 years prior to diagnosis than controls. The incidence rate of ALD correlated inversely with educational level, from 181 (95% CI, 167-197) to 910 (95% CI, 764-1086) per million person-years from the highest to the lowest educational level. By employment status, the incidence rate per million person-years was 211 (95% CI, 189-236) for employed and 3449 (95% CI, 2785-4271) for unemployed. Incidence rates increased gradually with age leading to larger inequalities in absolute numbers for older age-groups. Although ALD was rare in the younger age-groups, the relative differences in incidence rates between high and low socio-economic status were large for these ages. The pattern of socioeconomic inequality in ALD incidence was similar for men and women. Interpretation: This study showed substantial socioeconomic inequalities in ALD incidence for people aged 30-69 years. Funding: The study was supported by grants from the Novo Nordisk Foundation (NNF18OC0054612) and the Research Fund of Bispebjerg Hospital. (c) 2021 The Author(s). Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/)