Social exclusion (such as that experienced by people who are homeless, incarcerated or use drugs) increases morbidity across a range of diseases but is poorly captured in routine data sets. The aim of this study was to use a novel composite variable in a national-level hospital usage dataset to identify social exclusion and to determine whether social exclusion is associated with concurrent venous thromboembolism (VTE) in hospitalised patients in Ireland. Identifying and characterising this association in people who are socially excluded will inform VTE prevention and treatment strategies.

Retrospective cross-sectional study.

Irish Hospital Inpatient Enquiry (HIPE) system, which collects diagnostic information by International Classification of Diseases Tenth Revision code on all hospital admission episodes in the Ireland.

All hospital admission episodes involving a VTE diagnosis (in a primary ‘Dx 1’ or secondary ‘Dx 2–30’ coding position) during a 12-month period in the Ireland were identified from consolidated, national-level datasets derived from the Irish HIPE system. Social exclusion was defined as the presence of one or more indicators of homelessness, drug use, incarceration, health hazards due to socioeconomic status or episodes of healthcare terminated prematurely.

Of 5701 admission episodes involving a VTE diagnosis (in a primary or secondary position) during the study period, 271 (4.8%) related to an individual affected by social exclusion. Among hospitalised individuals identified as being socially excluded based on the novel composite variable, the likelihood of having a concurrent VTE diagnosis was over twofold greater than that observed in the general population (OR 2.14, 95% CI 1.79 to 2.26; p

These data suggest that VTE (primary and secondary) is over-represented in hospitalised socially excluded persons in Ireland and that the development of strategies to address this potentially life-threatening accompanying condition in this vulnerable patient group must be prioritised.